# Patent

## Title
Zoom optical system, optical device and method for manufacturing the zoom optical system

## Abstract

A zoom optical system comprises, in order from an object side: a first lens group having positive refractive power; a front-side lens group; an intermediate lens group having positive refractive power; and a rear-side lens group. The front-side lens group is composed of one or more lens groups and has a negative lens group. At least part of the intermediate lens group is a focusing lens group. The rear-side lens group is composed of one or more lens groups. Upon zooming, distances between the first lens group and the front-side lens group, between the front-side lens group and the intermediate lens group, and between the intermediate lens group and the rear-side lens group change. The following conditional expressions are satisfied:

−10.000<fF/fRF<10.000

0.010<|fF/fXR|<10.000

where fF denotes a focal length of the focusing lens group, fRF denotes a focal length of a lens group closest to the object side in the rear-side lens group, and fXR denotes a focal length of a lens group closet to an image surface in the front-side lens group.

## Background
INCORPORATION BY REFERENCE
This application is a division of application Ser. No. 16/880,945 filed May 21, 2020 (incorporated herein by reference), which is a division of application Ser. No. 16/601,602 filed Oct. 15, 2019 (incorporated herein by reference; now U.S. Pat. No. 10,684,455), which is a division of application Ser. No. 16/270,568 filed Feb. 7, 2019 (incorporated herein by reference; now U.S. Pat. No. 10,451,859), which is a division of application Ser. No. 15/984,344 filed May 19, 2018 (incorporated herein by reference; now U.S. Pat. No. 10,209,498), which is a division of application Ser. No. 15/430,027 filed Feb. 10, 2017 (incorporated herein by reference; now U.S. Pat. No. 10,018,814), which a continuation of International Application No. PCT/JP2015/004375 filed Aug. 28, 2015 (also incorporated herein by reference).


TECHNICAL FIELD
The present invention relates to a zoom optical system, an optical device, and a method for manufacturing the zoom optical system.
TECHNICAL BACKGROUND
A zoom optical system suitable for photographic cameras, electronic still cameras, video cameras, and the like has conventionally been proposed (see, for example, Patent Document 1).
Such a conventional zoom optical system includes a focusing group having a large number of lenses that is likely to lead to a large size and focusing involving large variation of image magnification.
A zoom optical system has conventionally been proposed that has an image blur (or image shake) correction mechanism and achieves focusing with smaller variation of image magnification (see, for example, Patent Document 2).
Such a conventional zoom optical system has a focusing group using a lens close to an image surface that can achieve focusing with smaller variation of image magnification but involves a large movement amount leading to a large size. Furthermore, the system involves a large and heavy vibration-proof lens group because the image blur correction is achieved with all three groups of plurality of lenses having a relatively large diameter.
A zoom optical system has conventionally been proposed that performs focusing with a second lens group including a relatively large number of lenses (see, for example, Patent Document 1).
This conventional technique is plagued by degradation of a performance upon focusing on short-distant object with the second lens group.
A zoom optical system suitable for photographic cameras, electronic still cameras, video cameras, and the like have conventionally been proposed (see, for example, Patent Document 2).
Such a conventional zoom optical system has a focusing group using a lens close to an image surface that can achieve focusing with smaller variation of image magnification but involves a large movement amount leading to a large size. Furthermore, the system involves a large and heavy vibration-proof lens group because the image blur correction is achieved with all three groups of plurality of lenses having a relatively large diameter.
A zoom optical system suitable for photographic cameras, electronic still cameras, video cameras, and the like has conventionally been proposed (see, for example, Patent Document 2).
Such a conventional zoom optical system has a focusing group using a lens close to an image surface that can achieve focusing with smaller variation of image magnification but involves a large movement amount leading to a large size.
PRIOR ART LIST
Patent Documents


    Patent Document 1: Japanese Laid-Open Patent Publication No. 2012-252278(A)
    Patent Document 2: Japanese Laid-Open Patent Publication No. 2010-276655(A)


SUMMARY OF THE INVENTION
Means to Solve the Problems
A zoom optical system according to the present invention comprises, in order from an object side, a first lens group having positive refractive power; a front-side lens group; an intermediate lens group having positive refractive power; and a rear-side lens group. Wherein the front-side lens group is composed of one or more lens groups and has a negative lens group, at least part of the intermediate lens group is a focusing lens group, the rear-side lens group is composed of one or more lens groups, upon zooming, the first lens group and the intermediate lens group are moved with respect to an image surface, a distance between the first lens group and the front-side lens group is changed, and a distance between the intermediate lens group and the rear-side lens group is changed, and the following conditional expression is satisfied:

0.000<βFw<0.800

where βFw denotes a lateral magnification of the focusing lens group in the wide-angle end state.
An optical device according to the present invention includes the zoom optical system above.
A method for manufacturing a zoom optical system according to the present invention comprises: arranging, in order from an object side, a first lens group having positive refractive power, a front-side lens group, an intermediate lens group having positive refractive power, and a rear-side lens group, wherein the front-side lens group is composed of one or more lens groups and has a negative lens group, at least part of the intermediate lens group is a focusing lens group, the rear-side lens group is composed of one or more lens groups, the lens groups are arranged in a lens barrel in such a manner that, upon zooming, the first lens group is moved with respect to an image surface, a distance between the first lens group and the front-side lens group is changed, a distance between the front-side lens group and the intermediate lens group is changed and a distance between the intermediate lens group and the rear-side lens group is changed, and the following conditional expression is satisfied:

0.000<βFw<0.800

where βFw denotes a lateral magnification of the focusing lens group in the wide-angle end state.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 1 respectively in a wide angle end state, an intermediate focal length state, and a telephoto end state.
FIG. 2 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 2 respectively in a wide angle end state, an intermediate focal length state, and a telephoto end state.
FIG. 3 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 3 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 4 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 4 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 5 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 5 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 6 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 6 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 7 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 7 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 8 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using a lens L51 as a vibration-proof lens group VR) according to Example 8 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 9 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using a lens L52 as a vibration-proof lens group VR) according to Example 8 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 10 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using the lens L51 as the vibration-proof lens group VR) according to Example 9 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 11 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using the lens L52 as the vibration-proof lens group VR) according to Example 9 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 12 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using the lens L51 as the vibration-proof lens group VR) according to Example 10 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 13 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using the lens L52 as the vibration-proof lens group VR) according to Example 10 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 14 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using the lens L51 as the vibration-proof lens group VR) according to Example 11 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 15 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system (using the lens L52 as the vibration-proof lens group VR) according to Example 11 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 16 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 12 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 17 is a cross-sectional view with sections (W), (M), and (T) showing a zoom optical system according to Example 13 respectively in the wide angle end state, the intermediate focal length state, and the telephoto end state.
FIG. 18 is a cross-sectional view of a zoom optical system according to Example 14.
FIG. 19 is a diagram illustrating a configuration of a camera including a zoom optical system according to 1st to 10th embodiments.
FIG. 20 is a diagram illustrating a method for manufacturing the zoom optical system according to the 1st embodiment.
FIG. 21 is a cross-sectional view of a zoom optical system according to Example 15.
FIG. 22 is a cross-sectional view of a zoom optical system according to Example 16.
FIG. 23 is a cross-sectional view of a zoom optical system according to Example 17.
FIG. 24 is a cross-sectional view of a zoom optical system according to Example 18.
FIG. 25 is a cross-sectional view of a zoom optical system according to Example 19.
FIG. 26 is a cross-sectional view of a zoom optical system according to Example 20.
FIG. 27 is a cross-sectional view of a zoom optical system according to Example 21.
FIG. 28 is a cross-sectional view of a zoom optical system according to Example 22.
FIG. 29 is a cross-sectional view of a zoom optical system according to Example 23.
FIG. 30 is a cross-sectional view of a zoom optical system according to Example 24.
FIG. 31 is a cross-sectional view of a zoom optical system according to Example 25.
FIG. 32 is a cross-sectional view of a zoom optical system according to Example 26.
FIG. 33 is a cross-sectional view of a zoom optical system according to Example 27.
FIG. 34 is a cross-sectional view of a zoom optical system according to Example 28.
FIG. 35 is a cross-sectional view of a zoom optical system according to Example 29.
FIG. 36 is a cross-sectional view of a zoom optical system according to Example 30.
FIG. 37 is a cross-sectional view of a zoom optical system according to Example 31.
FIG. 38 is a cross-sectional view of a zoom optical system according to Example 32.
FIG. 39 is a cross-sectional view of a zoom optical system according to Example 33.
FIG. 40 is a cross-sectional view of a zoom optical system according to Example 34.
FIG. 41 is a cross-sectional view of a zoom optical system according to Example 35.
FIG. 42 is a cross-sectional view of a zoom optical system according to Example 36.
FIG. 43 is a cross-sectional view of a zoom optical system according to Example 37.
FIG. 44 is a cross-sectional view of a zoom optical system according to Example 38.
FIG. 45 is a cross-sectional view of a zoom optical system according to Example 39.
FIG. 46 is a diagram illustrating a configuration of a camera including a zoom optical system according to 11th to 14th embodiments.
FIG. 47 is a diagram illustrating a method for manufacturing the zoom optical system according to the 11th embodiment.



DESCRIPTION OF THE EMBODIMENTS (1ST TO 10TH EMBODIMENTS)
In the description below, 1st to 10th embodiments are described with reference to drawings. A zoom optical system ZLI according to each of the embodiments includes a first lens group G1 having positive refractive power, a front-side lens group GX, an intermediate lens group GM having positive refractive power, and a rear-side lens group GR that are arranged in order from an object side. The front-side lens group GX is composed of one or more lens groups and has a negative lens group. At least part of the intermediate lens group GM is a focusing lens group GF. The rear-side lens group GR is composed of one or more lens groups. Upon zooming, the first lens group G1 is moved with respect to an image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed.
In the description of the 1st to the 10th embodiments below, a second lens group G2 is a lens group with a largest absolute value of refractive power in the negative lens group of the front-side lens group GX. A third lens group G3 is a lens group disposed closest to an image, in the front-side lens group GX. A fourth lens group G4 is the intermediate lens group GM at least partially including the focusing lens group GF. A fifth lens group G5 is a lens group disposed closest to an object, in the rear-side lens group GR. A sixth lens group G6 is a lens group disposed second closest to an object, in the rear-side lens group GR.
The 1st embodiment is described below with reference to drawings. The zoom optical system ZLI (ZL1) according to the 1st embodiment includes, as illustrated in FIG. 1, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. Upon zooming, the first lens group G1 is moved with respect to an image surface. Upon zooming from a wide angle end state to a telephoto end state, the fourth lens group G4 moves to the object side. Focusing is performed by moving at least part of the fourth lens group G4 as the focusing lens group GF in an optical axis direction. A forefront surface of the focusing lens group GF has a convex surface facing the object side.
With the above-described configuration including the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 and performing the zooming by changing a distance between the lens groups, downsizing and an excellent optical performance can be achieved. The configuration in which the first lens group G1 is moved with respect to an image surface upon zooming can achieve efficient zooming, and thus can achieve further downsizing and a higher performance. The configuration in which the fourth lens group G4 moves toward the object side with respect to the image surface upon zooming from the wide angle end state to the telephoto end state can reduce a spherical aberration. The configuration in which at least part of the fourth lens group G4 serves as the focusing lens group GF can reduce variation of image magnification, and variation of the spherical aberration and the curvature of field aberration upon focusing. The configuration in which the forefront surface of the focusing lens group GF (a lens surface of the fourth lens group G4 closest to an object) has the convex surface facing the object side can reduce variation of the spherical aberration.
The zoom optical system ZLI according to the 1st embodiment with the configuration described above satisfies the following conditional expressions (JA1) to (JA4).

0.430<|fF/fRF|<10.000  (JA1)

0.420<(−fXn)/fXR<2.000  (JA2)

0.010<fF/fW<8.000  (JA3)

32.000Wω  (JA4)

where, fF denotes a focal length of the focusing lens group GF,
fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5),
fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2),
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3),
fW denotes a focal length of the entire system in the wide angle end state, and
Wω denotes a half angle of view in the wide angle end state.
The conditional expression (JA1) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JA1) is satisfied.
A value higher than the upper limit value of the conditional expression (JA1) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA1) is preferably set to be 7.000. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA1) is preferably set to be 4.000. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA1) is preferably set to be 1.415. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA1) is preferably set to be 1.300.
A value lower than the lower limit value of the conditional expression (JA1) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA1) is preferably set to be 0.475. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA1) is preferably set to be 0.520.
The conditional expression (JA2) is for setting an appropriate value of the focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2), and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity can be achieved when the conditional expression (JA2) is satisfied.
A value higher than the upper limit value of the conditional expression (JA2) leads to a short focal length of the third lens group G3, and thus results in the third lens group G3 involving a large spherical aberration.
To guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA2) is preferably set to be 1.500. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA2) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JA2) leads to a short focal length of the second lens group G2, and thus results in the second lens group G2 involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA2) is preferably set to be 0.424. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA2) is preferably set to be 0.428.
The conditional expression (JA3) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the entire system in the wide angle end state. A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JA3) is satisfied.
A value higher than the upper limit value of the conditional expression (JA3) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length.
To guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA3) is preferably set to be 6.900. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA3) is preferably set to be 5.800.
A value lower than the lower limit value of the conditional expression (JA3) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA3) is preferably set to be 0.550. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA3) is preferably set to be 1.100.
The conditional expression (JA4) is for setting an appropriate value of the half angle of view in the wide angle end state. A value lower than the lower limit value of the conditional expression (JA4) results in failure to successfully correct the curvature of field aberration and distortion with a wide angle of view achieved.
To guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA4) is preferably set to be 35.000. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA4) is preferably set to be 38.000.
Preferably, the zoom optical system ZLI according to the 1st embodiment satisfies the following conditional expression (JA5).

0.010<fF/fXR<3.400  (JA5)

where, fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JA5) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JA5) is satisfied.
A value higher than the upper limit value of the conditional expression (JA5) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the third lens group G3 becomes short, and thus, the third lens group G3 involves a large spherical aberration.
To guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA5) is preferably set to be 3.300. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA5) is preferably set to be 3.200.
A value lower than the lower limit value of the conditional expression (JA5) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA5) is preferably set to be 0.300. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA5) is preferably set to be 0.650.
Preferably, the zoom optical system ZLI according to the 1st embodiment satisfies the following conditional expressions (JA6) and (JA7).

0.001<DXRFT/fF<1.500  (JA6)

Tω≤20.000  (JA7)

where, DXRFT denotes a distance between a lens group closest to an image in the front-side lens group GX and the focusing lens group GF in the telephoto end state (a distance between the third lens group G3 and the focusing lens group GF in the telephoto end state), and
Tω denotes a half angle of view in the telephoto end state.
The conditional expression (JA6) is for setting an appropriate value of the distance between the lens group closest to an image in the front-side lens group GX and the focusing lens group GF in the telephoto end state (the distance between the third lens group G3 and the focusing lens group GF in the telephoto end state) and the focal length of the focusing lens group GF. A sufficient performance upon focusing on short-distant object as well as downsizing can be achieved when the conditional expression (JA6) is satisfied.
A value higher than the upper limit value of the conditional expression (JA6) leads to a long distance between the third lens group G3 and the focusing lens group GF in the telephoto end state, and thus results in a large entire length. Furthermore, the value leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA6) is preferably set to be 0.800. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA6) is preferably set to be 0.400. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA6) is preferably set to be 0.230.
A value lower than the lower limit value of the conditional expression (JA6) leads to a short distance between the third lens group G3 and the focusing lens group GF in the telephoto end state, and thus results in a risk of collision between the third lens group G3 and the focusing lens group GF upon focusing. Furthermore, the value results in a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length.
To guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA6) is preferably set to be 0.020. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA6) is preferably set to be 0.040. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA6) is preferably set to be 0.070. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA6) is preferably set to be 0.114. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA6) is preferably set to be 0.130.
The conditional expression (JA7) is for setting an appropriate value of the half angle of view in the telephoto end state. A value higher than the upper limit value of the conditional expression (JA7) results in a failure to successfully correct the spherical aberration in the telephoto end state.
To guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA7) is preferably set to be 18.000. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA7) is preferably set to be 16.000.
Preferably, the zoom optical system ZLI according to the 1st embodiment satisfies the following conditional expression (JA8).

0.100<DGXR/fXR<1.500  (JA8)

where, DGXR denotes a thickness of the lens group closest to an image in the front-side lens group GX on an optical axis (the thickness of the third lens group G3 on the optical axis), and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JA8) is for setting an appropriate value of the thickness of the lens group (the third lens group G3) closest to an image in the front-side lens group GX on an optical axis (that is, a distance between a lens surface closest to an object in the third lens group G3 and a lens surface closest to an image in the third lens group G3 on the optical axis) and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity as well as excellent performance in terms of brightness can be achieved when the conditional expression (JA8) is satisfied. Furthermore, downsizing of the entire system can be achieved.
A value higher than the upper limit value of the conditional expression (JA8) leads to a short focal length of the third lens group G3, and thus results in the third lens group G3 involving a large spherical aberration. Furthermore, the value leads to the third lens group G3 with a larger thickness and thus results in a longer entire length.
To guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA8) is preferably set to be 1.200. To more effectively guarantee the effects of the 1st embodiment, the upper limit value of the conditional expression (JA8) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JA8) leads to a long focal length, that is, a large movement amount of the third lens group G3 upon zooming, and thus results in a large variation of the spherical aberration. Furthermore, the value leads to the third lens group G3 with a smaller thickness and thus more simple configuration, and thus results in the third lens group G3 involving a large spherical aberration.
To guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA8) is preferably set to be 0.250. To more effectively guarantee the effects of the 1st embodiment, the lower limit value of the conditional expression (JA8) is preferably set to be 0.350.
Preferably, in the zoom optical system ZLI according to the 1st embodiment, the second lens group G2 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 1st embodiment, the third lens group G3 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 1st embodiment, the fifth lens group G5 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
As described above, the 1st embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) including the above-described zoom optical system ZLI described above will be described with reference to FIG. 19. As illustrated in FIG. 19, this camera 1 is a lens interchangeable camera (what is known as a mirrorless camera) including the above-described zoom optical system ZLI as an imaging lens 2. In the camera 1, light from an unillustrated object (subject) is collected by the imaging lens 2 and passes through an unillustrated optical low pass filter (OLPF) to be a subject image formed on an imaging plane of an imaging unit 3. Then, the subject image is photoelectrically converted into an image of the subject by a photoelectric conversion element on the imaging unit 3. The image is displayed on an Electronic view finder (EVF) 4 provided to the camera 1. Thus, a photographer can monitor the subject through the EVF 4. When the photographer presses an unillustrated release button, the image of the subject generated by the imaging unit 3 is stored in an unillustrated memory. In this manner, the photographer can capture an image of a subject with the camera 1.
The zoom optical system ZLI according to the 1st embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 1st embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL1) will be described with reference to FIG. 20. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST110). The lenses are arranged in such a manner that the first lens group G1 is moved with respect to the image surface upon zooming (step ST120). The lenses are arranged in such a manner that at least part of the fourth lens group G4 moves toward the object side upon zooming from the wide angle end state to the telephoto end state (step ST130). The lenses are arranged in such a manner that the fourth lens group G4 moves as the focusing lens group GF in the optical axis direction upon focusing (step ST140). The lenses are arranged in such a manner that the forefront surface of the focusing lens group GF has a convex surface facing the object side (step ST150). The lenses are arranged to satisfy the following conditional expressions (JA1) to (JA4) (step ST160).

0.430<|fF/fRF|<10.000  (JA1)

0.420<(−fXn)/fXR<2.000  (JA2)

0.010<fF/fW<8.000  (JA3)

32.000≤Wω  (JA4)

where, fF denotes a focal length of the focusing lens group GF,
fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5),
fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2),
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3),
fW denotes a focal length of the entire system in the wide angle end state, and
Wω denotes a half angle of view in the wide angle end state.
In one example of the lens arrangement according to the 1st embodiment, as illustrated in FIG. 1, the first lens group G1 including a cemented lens including a negative meniscus lens L11 having a concave surface facing the image surface side and a biconvex lens L12, and a positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including a negative meniscus lens L21 having a concave surface facing the image surface side, a negative meniscus lens L22 having a concave surface facing the object side, a biconvex lens L23, and a negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including a biconvex lens L31, an aperture stop S, a cemented lens including a negative meniscus lens L32 having a concave surface facing the image surface side and a biconvex lens L33, a biconvex lens L34, and a cemented lens including a biconvex lens L35 and a biconcave lens L36, the fourth lens group G4 including a cemented lens including a biconvex lens L41 and a negative meniscus lens L42 having a concave surface facing the object side, and the fifth lens group G5 including a cemented lens including a positive meniscus lens L51 having a convex surface facing the image surface side and a biconcave lens L52, a biconvex lens L53, and a negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 1st embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 2nd embodiment is described below with reference to drawings. The zoom optical system ZLI (ZL1) according to the 2nd embodiment includes, as illustrated in FIG. 1, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. Upon zooming, the lenses move with respect to an image surface. Upon zooming from a wide angle end state to a telephoto end state, the fourth lens group G4 moves to the object side. Upon zooming from a wide angle end state to a telephoto end state, the distance between the fourth lens group G4 and the fifth lens group G5 increases. Focusing is performed by moving at least part of the fourth lens group G4 as the focusing lens group GF in the optical axis direction.
With the above-described configuration that includes the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5, and performs the zooming by changing a distance between the lens groups, downsizing and an excellent optical performance can be achieved. The configuration in which the lens groups move with respect to an image surface upon zooming can achieve efficient zooming, and thus can achieve further downsizing and a higher performance. The configuration in which upon zooming from the wide angle end state to the telephoto end state, the distance between the fourth lens group G4 and the fifth lens group G5 increases with the fourth lens group G4 moving toward the object side with respect to the image surface can achieve efficient zooming and reduce the variation of the spherical aberration and the curvature of field aberration. The configuration in which at least part of the fourth lens group G4 serves as the focusing lens group GF can reduce variation of variation of image magnification, the spherical aberration, and the curvature of field aberration upon focusing.
Preferably, the zoom optical system ZLI according to the 2nd embodiment satisfies the following conditional expressions (JB1) and (JB3).

0.001<(DMRT−DMRW)/fF<1.000  (JB1)

32.000≤Wω  (JB2)

Tω≤20.000  (JB3)

where, DMRW denotes a distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR in the wide angle end state (a distance between the fourth lens group G4 and the fifth lens group G5 in the wide angle end state),
DMRT denotes a distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR in the telephoto end state (a distance between the fourth lens group G4 and the fifth lens group G5 in the telephoto end state),
Wω denotes a half angle of view in the wide angle end state, and
Tω denotes a half angle of view in the telephoto end state.
The conditional expression (JB1) is for setting an appropriate value of the difference in the distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR (a distance between the fourth lens group G4 and the fifth lens group G5) between the wide angle end state and the telephoto end state, and the focal length of the focusing lens group GF. A sufficient performance upon focusing on short-distant object as well as downsizing can be achieved when the conditional expression (JB1) is satisfied.
A value higher than the upper limit value of the conditional expression (JB1) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB1) is preferably set to be 0.700. To more effectively guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB1) is preferably set to be 0.400.
A value lower than the lower limit value of the conditional expression (JB1) results in a small difference in the distance between the fourth lens group G4 and the fifth lens group G5 between the wide angle end state and the telephoto end state, and thus leads to a less configuration in terms of zooming and a large entire length. Furthermore, the value leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length.
To guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB1) is preferably set to be 0.010. To more effectively guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB1) is preferably set to be 0.020.
The conditional expression (JB2) is for setting an appropriate value of the half angle of view in the wide angle end state. A value lower than the lower limit value of the conditional expression (JB2) results in failure to successfully correct the curvature of field aberration and distortion with a wide angle of view achieved.
To guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB2) is preferably set to be 35.000. To more effectively guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB2) is preferably set to be 38.000.
The conditional expression (JB3) is for setting an appropriate value of the half angle of view in the telephoto end state. A value higher than the upper limit value of the conditional expression (JB3) results in a failure to successfully correct the spherical aberration in the telephoto end state.
To guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB3) is preferably set to be 18.000. To more effectively guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB3) is preferably set to be 16.000.
Preferably, the zoom optical system ZLI according to the 2nd embodiment satisfies the following conditional expression (JB4).

10.000<fF/fRF<10.000  (JB4)

where, fF denotes a focal length of the focusing lens group GF, and
fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5).
The conditional expression (JB4) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JB4) is satisfied.
A value higher than the upper limit value of the conditional expression (JB4) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB4) is preferably set to be 7.000. To more effectively guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB4) is preferably set to be 4.000.
A value lower than the lower limit value of the conditional expression (JB4) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB4) is preferably set to be −7.000. To more effectively guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB4) is preferably set to be −4.000. To more effectively guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB4) is preferably set to be −0.750. To more effectively guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB4) is preferably set to be −0.650.
Preferably, the zoom optical system ZLI according to the 2nd embodiment satisfies the following conditional expression (JB5).

0.010<fF/fXR<10.000  (JB5)

where, fF denotes a focal length of the focusing lens group GF, and
fXR: a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JB5) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JB5) is satisfied.
A value higher than the upper limit value of the conditional expression (JB5) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the third lens group G3 becomes short, and thus, the third lens group G3 involves a large spherical aberration.
To guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB5) is preferably set to be 8.000. To more effectively guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB5) is preferably set to be 6.000.
A value lower than the lower limit value of the conditional expression (JB5) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB5) is preferably set to be 0.300. To more effectively guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB5) is preferably set to be 0.650.
Preferably, the zoom optical system ZLI according to the 2nd embodiment satisfies the following conditional expression (JB6).

0.100<DGXR/fXR<1.500  (JB6)

where, DGXR denotes a thickness of the lens group closest to an image in the front-side lens group GX on the optical axis (the thickness of the third lens group G3 on the optical axis), and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JB6) is for setting an appropriate value of the thickness of the lens group (the third lens group G3) closest to an image in the front-side lens group GX on an optical axis (that is, a distance between a lens surface closest to an object in the third lens group G3 and a lens surface closest to an image in the third lens group G3 on the optical axis) and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity as well as excellent performance in terms of brightness can be achieved when the conditional expression (JB6) is satisfied. Furthermore, downsizing of the entire system can be achieved.
A value higher than the upper limit value of the conditional expression (JB6) leads to a short focal length of the third lens group G3, and thus results in the third lens group G3 involving a large spherical aberration. Furthermore, the value leads to the third lens group G3 with a larger thickness and thus results in a longer entire length.
To guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB6) is preferably set to be 1.200. To more effectively guarantee the effects of the 2nd embodiment, the upper limit value of the conditional expression (JB6) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JB6) leads to a long focal length, that is, a large movement amount of the third lens group G3 upon zooming, and thus results in a large variation of the spherical aberration. Furthermore, the value leads to the third lens group G3 with a smaller thickness and thus more simple configuration, and thus results in the third lens group G3 involving a large spherical aberration.
To guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB6) is preferably set to be 0.250. To more effectively guarantee the effects of the 2nd embodiment, the lower limit value of the conditional expression (JB6) is preferably set to be 0.350.
In the zoom optical system ZLI according to the 2nd embodiment, the third lens group G3 preferably includes the aperture stop S and a lens that is disposed next to and on an image side of the aperture stop S and has a convex surface facing the object side.
The configuration can reduce the spherical aberration generated upon zooming.
Preferably, in the zoom optical system ZLI according to the 2nd embodiment, upon zooming from the wide angle end state to the telephoto end state, the distance between the third lens group G3 and the fourth lens group G4 increases as it gets closer to the intermediate focal length state from the wide angle end state and decreases as it gets closer to the telephoto end state from the intermediate focal length state.
The configuration can reduce the curvature of field aberration generated upon zooming.
As described above, the 2nd embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 2nd embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 2nd embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL1) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST210). The lenses are arranged in such a manner that the lens groups move with respect to the image surface upon zooming (step ST220). The lenses are arranged in such a manner that the fourth lens group G4 moves toward the object side upon zooming from the wide angle end state to the telephoto end state (step ST230). The lenses are arranged in such a manner that the distance between the fourth lens group G4 and the fifth lens group G5 increases upon zooming from the wide angle end state to the telephoto end state (step ST240). The lenses are arranged in such a manner that the at least part of the fourth lens group G4 moves as the focusing lens group GF in the optical axis direction upon focusing (step ST250).
In one example of the lens arrangement according to the 2nd embodiment, as illustrated in FIG. 1, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the negative meniscus lens L22 having a concave surface facing the object side, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31 the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, and the fifth lens group G5 including the cemented lens including a positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 2nd embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 3rd embodiment is described below with reference to drawings. The zoom optical system ZLI (ZL2) according to the 3rd embodiment includes, as illustrated in FIG. 2, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5, and the sixth lens group G6 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. Upon zooming, the first lens group G1 is moved with respect to an image surface. Upon zooming from a wide angle end state to a telephoto end state, the fourth lens group G4 moves to the object side. Upon zooming from a wide angle end state to a telephoto end state, the distance between the fourth lens group G4 and the fifth lens group G5 increases. Focusing is performed by moving at least part of the fourth lens group G4 as the focusing lens group GF in an optical axis direction.
With the above-described configuration that includes the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5, and the sixth lens group G6 and performs the zooming by changing a distance between the lens groups, downsizing and an excellent optical performance can be achieved. The configuration in which the first lens group G1 moves to an image surface upon zooming can achieve efficient zooming, and thus can achieve further downsizing and a higher performance. The configuration in which upon zooming from the wide angle end state to the telephoto end state, the distance between the fourth lens group G4 and the fifth lens group G5 increases with the fourth lens group G4 moved toward the object side with respect to the image surface can achieve efficient zooming and reduce variation of the spherical aberration and the curvature of field aberration. The configuration in which at least part of the fourth lens group G4 serves as the focusing lens group GF can reduce variation of the image magnification, the spherical aberration, and the curvature of field aberration upon focusing.
The zoom optical system ZLI according to the 3rd embodiment with the configuration described above satisfies the following conditional expressions (JC1) to (JC4).

0.170<|fF/fRF|<10.000  (JC1)

0.010<(DMRT−DMRW)/fF<1.000  (JC2)

32.000≤Wω  (JC3)

Tω≤20.000  (JC4)

where, fF denotes a focal length of the focusing lens group GF,
fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5),
DMRW denotes a distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR in the wide angle end state (a distance between the fourth lens group G4 and the fifth lens group G5 in the wide angle end state),
DMRT denotes a distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR in the telephoto end state (a distance between the fourth lens group G4 and the fifth lens group G5 in the telephoto end state),
Wω denotes a half angle of view in the wide angle end state, and
Tω denotes a half angle of view in the telephoto end state.
The conditional expression (JC1) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JC1) is satisfied.
A value higher than the upper limit value of the conditional expression (JC1) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC1) is preferably set to be 7.000. To more effectively guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC1) is preferably set to be 4.000.
A value lower than the lower limit value of the conditional expression (JC1) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC1) is preferably set to be 0.260. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC1) is preferably set to be 0.350.
The conditional expression (JC2) is for setting an appropriate value of a difference in the distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR (a distance between the fourth lens group G4 and the fifth lens group G5) between the wide angle end state and the telephoto end state, and the focal length of the focusing lens group GF. A sufficient performance upon focusing on short-distant object as well as downsizing can be achieved when the conditional expression (JC2) is satisfied.
A value higher than the upper limit value of the conditional expression (JC2) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC2) is preferably set to be 0.820. To more effectively guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC2) is preferably set to be 0.640.
A value lower than the lower limit value of the conditional expression (JC2) results in a small difference in the distance between the fourth lens group G4 and the fifth lens group G5 between the wide angle end state and the telephoto end state, and thus leads to a less advantageous zooming and a large entire length. Furthermore, the value results in a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length.
To guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC2) is preferably set to be 0.016. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC2) is preferably set to be 0.023. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC2) is preferably set to be 0.027. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC2) is preferably set to be 0.050.
The conditional expression (JC3) is for setting an appropriate value of the half angle of view in the wide angle end state. A value lower than the lower limit value of the conditional expression (JC3) results in failure to successfully the curvature of field aberration and distortion with a wide angle of view achieved.
To guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC3) is preferably set to be 35.000. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC3) is preferably set to be 38.000.
The conditional expression (JC4) is for setting an appropriate value of the half angle of view in the telephoto end state. A value higher than the upper limit value of the conditional expression (JC4) results in a failure to successfully correct the spherical aberration in the telephoto end state.
To guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC4) is preferably set to be 18.000. To more effectively guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC4) is preferably set to be 16.000.
Preferably, the zoom optical system ZLI according to the 3rd embodiment satisfies the following conditional expression (JC5).

10.000<fRF/fRF2<10.000  (JC5)

where, fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5), and
fRF2 denotes a focal length of the lens group second closest to an object in the rear-side lens group GR (the focal length of the sixth lens group G6).
The conditional expression (JC5) is for setting an appropriate value of the focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5) and the focal length of the lens group second closest to an object in the rear-side lens group GR (the focal length of the sixth lens group G6). A sufficient performance upon focusing on infinity can be achieved when the conditional expression (JC5) is satisfied.
A value higher than the upper limit value of the conditional expression (JC5) results in a short focal length of the sixth lens group G6, and thus leads to the fifth lens group G5 involving a large curvature of field aberration.
To guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC5) is preferably set to be 5.000. To more effectively guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC5) is preferably set to be 3.000. To more effectively guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC5) is preferably set to be 2.500.
A value lower than the lower limit value of the conditional expression (JC5) results in a short focal length of the sixth lens group G6, and thus leads to the fifth lens group G5 involving a large curvature of field aberration.
To guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC5) is preferably set to be −5.000. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC5) is preferably set to be −3.000. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC5) is preferably set to be −2.500.
Preferably, the zoom optical system ZLI according to the 3rd embodiment satisfies the following conditional expression (JC6).

0.100<DGXR/fXR<1.500  (JC6)

where, DGXR denotes a thickness of the lens group closest to an image in the front-side lens group GX on an optical axis (the thickness of the third lens group G3 on the optical axis), and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JC6) is for setting an appropriate value of the thickness of the lens group (the third lens group G3) closest to an image in the front-side lens group GX on the optical axis (that is, a distance between a lens surface closest to an object in the third lens group G3 and a lens surface closest to an image in the third lens group G3 on the optical axis) and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity as well as excellent performance in terms of brightness can be achieved when the conditional expression (JC6) is satisfied. Furthermore, downsizing of the entire system can be achieved.
A value higher than the upper limit value of the conditional expression (JC6) leads to a short focal length of the third lens group G3, and thus results in the third lens group G3 involving a large spherical aberration. Furthermore, the value leads to the third lens group G3 with a larger thickness and thus results in a longer entire length.
To guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC6) is preferably set to be 1.200. To more effectively guarantee the effects of the 3rd embodiment, the upper limit value of the conditional expression (JC6) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JC6) leads to a long focal length, that is, a large movement amount of the third lens group G3 upon zooming upon focusing, and thus results in a large variation of the spherical aberration. Furthermore, the value leads to the third lens group G3 with a smaller thickness and thus more simple configuration, and thus results in the third lens group G3 involving a large spherical aberration.
To guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC6) is preferably set to be 0.250. To more effectively guarantee the effects of the 3rd embodiment, the lower limit value of the conditional expression (JC6) is preferably set to be 0.350.
Preferably, in the zoom optical system ZLI according to the 3rd embodiment the second lens group G2 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 3rd embodiment, the third lens group G3 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 3rd embodiment, the fifth lens group G5 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
As described above, the 3rd embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 3rd embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 3rd embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL2) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5, and the sixth lens group G6 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST310). The lenses are arranged in such a manner that the first lens group G1 is moved with respect to the image surface upon zooming (step ST320). The lenses are arranged in such a manner that the fourth lens group G4 moves toward the object side upon zooming from the wide angle end state to the telephoto end state (step ST330). The lenses are arranged in such a manner that the distance between the fourth lens group G4 and the fifth lens group G5 increases upon zooming from the wide angle end state to the telephoto end state (step ST340). The lenses are arranged in such a manner that the at least part of the fourth lens group G4 moves as the focusing lens group GF in the optical axis direction upon focusing (step ST350). The lenses are arranged to satisfy the following conditional expressions (JC1) to (JC4) (step ST360).

0.170<|fF/fRF|<10.000  (JC1)

0.010<(DMRT−DMRW)/fF<1.000  (JC2)

32.000≤Wω  (JC3)

Tω≤20.000  (JC4)

where, fF denotes a focal length of the focusing lens group GF,
fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5),
DMRW denotes a distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR in the wide angle end state (a distance between the fourth lens group G4 and the fifth lens group G5 in the wide angle end state),
DMRT denotes a distance between the intermediate lens group GM and a lens group closest to an object in the rear-side lens group GR in the telephoto end state (a distance between the fourth lens group G4 and the fifth lens group G5 in the telephoto end state),
Wω denotes a half angle of view in the wide angle end state, and
Tω denotes a half angle of view in the telephoto end state.
In one example of the lens arrangement according to the 3rd embodiment, as illustrated in FIG. 2, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, a biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, the fifth lens group G5 including the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side, and the sixth lens group G6 including a plano-convex lens L61 having a convex surface facing the object side are arranged in order from the object side. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 3rd embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 4th embodiment is described below with reference to drawings. The zoom optical system ZLI (ZL1) according to the 4th embodiment includes, as illustrated in FIG. 1, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. Upon zooming, the first lens group G1 moves to an image surface. Focusing is performed by moving at least part of the fourth lens group G4 as the focusing lens group GF in an optical axis direction. A vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, and is configured to be movable with a displacement component in a direction orthogonal to the optical axis to correct image blur.
With the above-described configuration that includes the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5, and performs the zooming by changing a distance between the lens groups, downsizing and an excellent optical performance can be achieved. The configuration in which the first lens group G1 moves to an image surface upon zooming can achieve efficient zooming, and thus can achieve further downsizing and a higher performance. The configuration in which at least part of the fourth lens group G4 serves as the focusing lens group GF can reduce variation of image magnification, and variation of the spherical aberration and the curvature of field aberration upon focusing. In the configuration in which the vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, decentering coma aberration and curvature of field aberration can be corrected upon image blur correction.
The zoom optical system ZLI according to the 4th embodiment with the configuration described above satisfies the following conditional expression (JD1).

−1.500<fV/fRF<0.645  (JD1)

where, fV denotes a focal length of the vibration-proof lens group VR, and
fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5).
The conditional expression (JD1) is for setting an appropriate value of the focal length of the vibration-proof lens group VR and the focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5). A sufficient vibration-proof performance can be achieved when the conditional expression (JD1) is satisfied.
A value higher than the upper limit value of the conditional expression (JD1) results in a long focal length, that is, a large movement amount of the vibration-proof lens group VR upon image blur correction, making the decentering coma aberration and curvature of field aberration difficult to correct. The larger amount of the movement of the vibration-proof lens group VR leads to a larger diameter, rendering driving control for the vibration-proof lens group VR difficult. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD1) is preferably set to be 0.643. To more effectively guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD1) is preferably set to be 0.641.
A value lower than the lower limit value of the conditional expression (JD1) results in a long focal length, that is, a large movement amount of the vibration-proof lens group VR upon image blur correction, making the decentering coma aberration and curvature of field aberration difficult to correct. The larger amount of the movement of the vibration-proof lens group VR leads to a larger diameter, rendering driving control for the vibration-proof lens group VR difficult. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD1) is preferably set to be −1.081. To more effectively guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD1) is preferably set to be −0.662.
Preferably, the zoom optical system ZLI according to the 4th embodiment satisfies the following conditional expressions (JD2) and (JD3).

−1.000<DVW/fV<1.000  (JD2)

32.000≤Wω  (JD3)

where, DVW denotes a distance between the vibration-proof lens group VR and a next lens in the wide angle end state, and
Wω denotes a half angle of view in the wide angle end state.
The conditional expression (JD2) is for setting an appropriate value of the distance between the vibration-proof lens group VR and a next lens in the wide angle end state, and the focal length of the vibration-proof lens group VR. A sufficient vibration-proof performance can be achieved when the conditional expression (JD2) is satisfied.
A value higher than the upper limit value of the conditional expression (JD2) results in the distance being large making the decentering coma aberration and the curvature of field aberration generated at the vibration-proof lens group VR difficult to correct by the lenses after the vibration-proof lens group VR. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration that are difficult to correct.
To guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD2) is preferably set to be 0.600. To more effectively guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD2) is preferably set to be 0.250.
A value lower than the lower limit value of the conditional expression (JD2) results in the distance being large making the decentering coma aberration and the curvature of field aberration generated at the vibration-proof lens group VR difficult to correct by a lens after the vibration-proof lens group VR. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration that are difficult to correct.
To guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD2) is preferably set to be −0.750. To more effectively guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD2) is preferably set to be −0.400.
The conditional expression (JD3) is for setting an appropriate value of the half angle of view in the wide angle end state. A value lower than the lower limit value of the conditional expression (JD3) results in failure to successfully correct the curvature of field aberration and distortion with a wide angle of view achieved.
To guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD3) is preferably set to be 35.000. To more effectively guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD3) is preferably set to be 38.000.
Preferably, the zoom optical system according to the 4th embodiment satisfies the following conditional expression (JD4).

0.010<fF/fXR<10.000  (JD4)

where, fF denotes a focal length of the focusing lens group GF, and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JD4) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JD4) is satisfied.
A value higher than the upper limit value of the conditional expression (JD4) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the third lens group G3 becomes short, and thus, the third lens group G3 involves a large spherical aberration.
To guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD4) is preferably set to be 8.000. To more effectively guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD4) is preferably set to be 6.000.
A value lower than the lower limit value of the conditional expression (JD4) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD4) is preferably set to be 0.300. To more effectively guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD4) is preferably set to be 0.650.
Preferably, the zoom optical system ZLI according to the 4th embodiment satisfies the following conditional expression (JD5).

0.010<(−fXn)/fXR<1.000  (JD5)

where, fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2), and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JD5) is for setting an appropriate value of the focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2), and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity as well as downsizing of the entire system can be achieved when the conditional expression (JD5) is satisfied.
A value higher than the upper limit value of the conditional expression (JD5) results in a long focal length, that is, a large movement amount of the second lens group G2 upon focusing, leading to large variation of spherical aberration and curvature of field aberration. The larger movement amount of the second lens group G2 upon focusing leads to larger diameter and entire length. Furthermore, the focal length of the third lens group (G3) becomes short, and thus, the third lens group (G3) involves a large spherical aberration.
To guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD5) is preferably set to be 0.800. To more effectively guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD5) is preferably set to be 0.650.
A value lower than the lower limit value of the conditional expression (JD5) leads to a short focal length of the second lens group G2, and thus results in the second lens group G2 involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD5) is preferably set to be 0.130. To more effectively guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD5) is preferably set to be 0.250.
Preferably, the zoom optical system ZLI according to the 4th embodiment satisfies the following conditional expression (JD6).

0.100<DGXR/fXR<1.500  (JD6)

where, DGXR denotes a thickness of the lens group closest to an image in the front-side lens group GX on an optical axis (the thickness of the third lens group G3 on the optical axis), and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JD6) is for setting an appropriate value of the thickness of the lens group (the third lens group G3) closest to an image in the front-side lens group GX on an optical axis (that is, a distance between a lens surface closest to an object in the third lens group G3 and a lens surface closest to an image in the third lens group G3 on the optical axis) and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity as well as excellent performance in terms of brightness can be achieved when the conditional expression (JD6) is satisfied. Furthermore, downsizing of the entire system can be achieved.
A value higher than the upper limit value of the conditional expression (JD6) leads to a short focal length of the third lens group G3, and thus results in the third lens group G3 involving a large spherical aberration. Furthermore, the value leads to the third lens group G3 with a larger thickness and thus results in a longer entire length.
To guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD6) is preferably set to be 1.200. To more effectively guarantee the effects of the 4th embodiment, the upper limit value of the conditional expression (JD6) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JD6) leads to a long focal length, that is, a large movement amount of the third lens group G3 upon zooming, and thus results in a large variation of the spherical aberration. Furthermore, the value leads to the third lens group G3 with a smaller thickness and thus more simple configuration, and thus results in the third lens group G3 involving a large spherical aberration.
To guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD6) is preferably set to be 0.250. To more effectively guarantee the effects of the 4th embodiment, the lower limit value of the conditional expression (JD6) is preferably set to be 0.350.
Preferably, in the zoom optical system ZLI according to the 4th embodiment, the second lens group G2 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 4th embodiment, the third lens group G3 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 4th embodiment, the fourth lens group G4 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 4th embodiment, the fifth lens group G5 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 4th embodiment, part of the fifth lens group G5 is preferably the vibration-proof lens group VR.
The configuration is effective for correcting the decentering coma aberration and the curvature of field aberration upon image blur correction. The vibration-proof lens group VR is part of the group and is not the group as a whole, and thus can have a small size.
As described above, the 4th embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 4th embodiment, installed in the camera 1 as the imaging lens 2, features a small size, and small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 4th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL1) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST410). The lenses are arranged in such a manner that the first lens group G1 is moved with respect to the image surface upon zooming (step ST420). The lenses are arranged in such a manner that the at least part of the fourth lens group G4 moves as the focusing lens group GF in the optical axis direction upon focusing (step ST430). The lenses are arranged in such a manner that the vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, and is configured to be movable with a displacement component in a direction orthogonal to the optical axis to correct image blur (step ST440). The lenses are arranged to satisfy the following conditional expression (JD1) (step ST450).

1.500<fV/fRF<0.645  (JD1)

where, fV: a focal length of the vibration-proof lens group VR, and
fRF: a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5).
In one example of the lens arrangement according to the 4th embodiment, as illustrated in FIG. 1, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the negative meniscus lens L22 having a concave surface facing the object side, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, and the fifth lens group G5 including the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The cemented lens including the lenses L51 and L52 forming the fifth lens group G5 serves as the vibration-proof lens group VR. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 4th embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 5th embodiment is described below with reference to drawings. The zoom optical system ZLI (ZL1) according to the 5th embodiment includes, as illustrated in FIG. 1, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. Upon zooming, the first lens group G1 moves to an image surface. Focusing is performed by moving at least part of the fourth lens group G4 as the focusing lens group GF in an optical axis direction. The vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, and is configured to be movable with a displacement component in a direction orthogonal to the optical axis to correct image blur.
With the above-described configuration that includes the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5, and performs the zooming by changing a distance between the lens groups, downsizing and an excellent optical performance can be achieved. The configuration in which the first lens group G1 moves to an image surface upon zooming can achieve efficient zooming, and thus can achieve further downsizing and a higher performance. The configuration in which at least part of the fourth lens group G4 serves as the focusing lens group GF can reduce variation of image magnification, and variation of the spherical aberration and the curvature of field aberration upon focusing. In the configuration in which the vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, decentering coma aberration and curvature of field aberration can be corrected upon image blur correction.
A zoom optical system ZLI according to the 5th embodiment with the configuration described above satisfies the following conditional expressions (JE1) and (JE2).

−0.150<DVW/fV<1.000  (JE1)

32.000≤Wω  (JE2)

where, DVW denotes a distance between the vibration-proof lens group VR and a next lens in the wide angle end state,
fV denotes a focal length of the vibration-proof lens group VR, and
Wω denotes a half angle of view in the wide angle end state.
The conditional expression (JE1) is for setting an appropriate value of the distance between the vibration-proof lens group VR and a next lens in the wide angle end state, and the focal length of the vibration-proof lens group VR. A sufficient vibration-proof performance can be achieved when the conditional expression (JE1) is satisfied.
A value higher than the upper limit value of the conditional expression (JE1) results in the distance being large making the decentering coma aberration and the curvature of field aberration generated at the vibration-proof lens group VR difficult to correct by a lens after the vibration-proof lens group VR. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration that are difficult to correct.
To guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE1) is preferably set to be 0.691. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE1) is preferably set to be 0.383.
A value lower than the lower limit value of the conditional expression (JE1) results in the distance being large making the decentering coma aberration and the curvature of field aberration generated at the vibration-proof lens group VR difficult to correct by a lens after the vibration-proof lens group VR. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration that are difficult to correct.
To guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE1) is preferably set to be −0.141. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE1) is preferably set to be −0.132.
The conditional expression (JE2) is for setting an appropriate value of the half angle of view in the wide angle end state. A value lower than the lower limit value of the conditional expression (JE2) results in failure to successfully correct the curvature of field aberration and distortion with a wide angle of view achieved.
To guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE2) is preferably set to be 35.000. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE2) is preferably set to be 38.000.
Preferably, the zoom optical system ZLI according to the 5th embodiment satisfies the following conditional expression (JE3).

0.001<fF/fW<20.000  (JE3)

where, fF denotes a focal length of the focusing lens group GF, and
fW denotes a focal length of the entire system in the wide angle end state.
The conditional expression (JE3) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the entire system in the wide angle end state. A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JE3) is satisfied.
A value higher than the upper limit value of the conditional expression (JE3) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length.
To guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE3) is preferably set to be 15.000. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE3) is preferably set to be 10.000. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE3) is preferably set to be 8.500.
A value lower than the lower limit value of the conditional expression (JE3) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE3) is preferably set to be 0.400. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE3) is preferably set to be 0.800. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE3) is preferably set to be 1.150.
Preferably, the zoom optical system ZLI according to the 5th embodiment satisfies the following conditional expression (JE4).

−1.000<fV/fRF<2.000  (JE4)

where, fRF: a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5).
The conditional expression (JE4) is for setting an appropriate value of the focal length of the vibration-proof lens group VR and the focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5). A sufficient vibration-proof performance can be achieved when the conditional expression (JE4) is satisfied.
A value higher than the upper limit value of the conditional expression (JE4) results in a long focal length, that is, a large movement amount of the vibration-proof lens group VR upon image blur correction, making the decentering coma aberration and curvature of field aberration difficult to correct. The larger amount of the movement of the vibration-proof lens group VR leads to a larger diameter, rendering driving control for the vibration-proof lens group VR difficult. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE4) is preferably set to be 1.600. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE4) is preferably set to be 1.300.
A value lower than the lower limit value of the conditional expression (JE4) results in a long focal length, that is, a large movement amount of the vibration-proof lens group VR upon image blur correction, making the decentering coma aberration and curvature of field aberration difficult to correct. The larger amount of the movement of the vibration-proof lens group VR leads to a larger diameter, rendering driving control for the vibration-proof lens group VR difficult. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE4) is preferably set to be −0.750. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE4) is preferably set to be −0.435.
Preferably, the zoom optical system ZLI according to the 5th embodiment satisfies the following conditional expression (JE5).

0.010<fF/fXR<10.000  (JE5)

where, fF denotes a focal length of the focusing lens group GF, and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JE5) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JE5) is satisfied.
A value higher than the upper limit value of the conditional expression (JE5) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the third lens group G3 becomes short, and thus, the third lens group G3 involves a large spherical aberration.
To guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE5) is preferably set to be 8.000. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE5) is preferably set to be 6.000.
A value lower than the lower limit value of the conditional expression (JE5) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE5) is preferably set to be 0.300. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE5) is preferably set to be 0.650.
Preferably, the zoom optical system ZLI according to the 5th embodiment satisfies the following conditional expression (JE6).

0.100<DGXR/fXR<1.500  (JE6)

where, DGXR denotes a thickness of the lens group closest to an image in the front-side lens group GX on an optical axis (the thickness of the third lens group G3 on the optical axis), and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JE6) is for setting an appropriate value of the thickness of the lens group (the third lens group G3) closest to an image in the front-side lens group GX on an optical axis (that is, a distance between a lens surface closest to an object in the third lens group G3 and a lens surface closest to an image in the third lens group G3 on the optical axis) and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity as well as excellent performance in terms of brightness can be achieved when the conditional expression (JE6) is satisfied. Furthermore, downsizing of the entire system can be achieved.
A value higher than the upper limit value of the conditional expression (JE6) leads to a short focal length of the third lens group G3, and thus results in the third lens group G3 involving a large spherical aberration. Furthermore, the value leads to the third lens group G3 with a larger thickness and thus results in a longer entire length.
To guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE6) is preferably set to be 1.200. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE6) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JE6) leads to a long focal length, that is, a large movement amount of the third lens group G3 upon zooming, and thus results in a large variation of the spherical aberration. Furthermore, the value leads to the third lens group G3 with a smaller thickness and thus more simple configuration, and thus results in the third lens group G3 involving a large spherical aberration.
To guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE6) is preferably set to be 0.250. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE6) is preferably set to be 0.350.
Preferably, the zoom optical system ZLI according to the 5th embodiment satisfies the following conditional expression (JE7).

0.390<DXnW/ZD1<5.000  (JE7)

where, DXnW denotes a distance between a lens group with the largest absolute value of the refractive power in the negative lens groups of the front-side lens group GX and a lens group closest to the image in the front-side lens group GX in the wide angle end state, and
ZD1 denotes a movement amount of the first lens group G1 upon zooming from the wide angle end state to the telephoto end state.
The conditional expression (JE7) is for setting an appropriate value of the distance between a lens group (second lens group G2) with the largest absolute value of the refractive power in the negative lens groups of the front-side lens group GX and the lens group (third lens group G3) closest to the image in the front-side lens group GX in the wide angle end state, and the movement amount of the first lens group G1 upon zooming from the wide angle end state to the telephoto end state. An excellent optical performance can be achieved when the conditional expression (JE7) is satisfied.
A value higher than the upper limit value of the conditional expression (JE7) results in a large distance between a lens group with the largest absolute value of the refractive power in the negative lens groups of the front-side lens group GX and the lens group closest to the image in the front-side lens group GX (that is, a distance between the second lens group G2 and the third lens group G3), and thus results in curvature of field aberration in the wide angle end state.
To guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE7) is preferably set to be 4.000. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE7) is preferably set to be 3.000. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE7) is preferably set to be 2.000. To more effectively guarantee the effects of the 5th embodiment, the upper limit value of the conditional expression (JE7) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JE7) leads to a movement amount of the first lens group G1, and thus results in a zooming involving a large variation of the curvature of field aberration.
To guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE7) is preferably set to be 0.400. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE7) is preferably set to be 0.410. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE7) is preferably set to be 0.420. To more effectively guarantee the effects of the 5th embodiment, the lower limit value of the conditional expression (JE7) is preferably set to be 0.430.
Preferably, in the zoom optical system ZLI according to the 5th embodiment, the second lens group G2 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 5th embodiment, the third lens group G3 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 5th embodiment, the fourth lens group G4 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 5th embodiment, the fifth lens group G5 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 5th embodiment, part of the fifth lens group G5 is preferably the vibration-proof lens group VR.
The configuration is effective for correcting the decentering coma aberration and the curvature of field aberration upon image blur correction. The vibration-proof lens group VR is part of the group and is not the group as a whole, and thus can have a small size.
As described above, the 5th embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 5th embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 5th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL1) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST510). The lenses are arranged in such a manner that the first lens group G1 is moved with respect to the image surface upon zooming (step ST520). The lenses are arranged in such a manner that the at least part of the fourth lens group G4 moves as the focusing lens group GF in the optical axis direction upon focusing (step ST530). The lenses are arranged in such a manner that the vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, and is configured to be movable with a displacement component in a direction orthogonal to the optical axis to correct image blur (step ST540). The lenses are arranged to satisfy the following conditional expressions (JE1) and (JE2) (step ST550).

−0.150<DVW/fV<1.000  (JE1)

32.000≤Wω  (JE2)

where, DVW denotes a distance between the vibration-proof lens group VR and a next lens in the wide angle end state,
fV denotes a focal length of the vibration-proof lens group VR, and
Wω denotes a half angle of view in the wide angle end state.
In one example of the lens arrangement according to the 5th embodiment, as illustrated in FIG. 1, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the negative meniscus lens L22 having a concave surface facing the object side, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, and the fifth lens group G5 including the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The cemented lens including the lenses L51 and L52 forming the fifth lens group G5 serves as the vibration-proof lens group VR. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 5th embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 6th embodiment is described below with reference to drawings. The zoom optical system ZLI (ZL2) according to the 6th embodiment includes, as illustrated in FIG. 2, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5, and the sixth lens group G6 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. Upon zooming, the first lens group G1 moves to an image surface. Focusing is performed by moving at least part of the fourth lens group G4 as the focusing lens group GF in an optical axis direction. The vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, and is configured to be movable with a displacement component in a direction orthogonal to the optical axis to correct image blur.
With the above-described configuration that includes the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5, and the sixth lens group G6 and performs the zooming by changing a distance between the lens groups, downsizing and an excellent optical performance can be achieved. The configuration in which the first lens group G1 moves to an image surface upon zooming can achieve efficient zooming, and thus can achieve further downsizing and a higher performance. The configuration in which at least part of the fourth lens group G4 serves as the focusing lens group GF can reduce variation of image magnification and variation of the spherical aberration and the curvature of field aberration upon focusing. In the configuration in which the vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, decentering coma aberration and curvature of field aberration can be corrected upon image blur correction.
Preferably, the zoom optical system ZLI according to the 6th embodiment satisfies the following conditional expression (JF1).

−20.000<fF/fV<20.000  (JF1)

where, fF denotes a focal length of the focusing lens group GF, and
fV denotes a focal length of the vibration-proof lens group VR.
The conditional expression (JF1) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the vibration-proof lens group.
A value higher than the upper limit value of the conditional expression (JF1) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration.
To guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF1) is preferably set to be 15.000. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF1) is preferably set to be 10.000.
A value lower than the lower limit value of the conditional expression (JF1) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration.
To guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF1) is preferably set to be −15.000. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF1) is preferably set to be −10.000.
Preferably, the zoom optical system ZLI according to the 6th embodiment satisfies the following conditional expression (JF2).

−15.000<fV/fRF<10.000  (JF2)

where, fV denotes a focal length of the vibration-proof lens group VR, and
fRF denotes a focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5).
The conditional expression (JF2) is for setting an appropriate value of the focal length of the vibration-proof lens group VR and the focal length of the lens group closest to an object in the rear-side lens group GR (the focal length of the fifth lens group G5). A sufficient vibration-proof performance can be achieved when the conditional expression (JF2) is satisfied.
A value higher than the upper limit value of the conditional expression (JF2) results in a long focal length, that is, a large movement amount of the vibration-proof lens group VR upon image blur correction, making the decentering coma aberration and curvature of field aberration difficult to correct. The larger amount of the movement of the vibration-proof lens group VR leads to a larger diameter, rendering driving control for the vibration-proof lens group VR difficult. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF2) is preferably set to be 7.500. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF2) is preferably set to be 5.000.
A value lower than the lower limit value of the conditional expression (JF2) results in a long focal length, that is, a large movement amount of the vibration-proof lens group VR upon image blur correction, making the decentering coma aberration and curvature of field aberration difficult to correct. The larger amount of the movement of the vibration-proof lens group VR leads to a larger diameter, rendering driving control for the vibration-proof lens group VR difficult. Furthermore, the focal length of the fifth lens group G5 becomes short, and thus, the fifth lens group G5 involves a large curvature of field aberration.
To guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF2) is preferably set to be −13.000. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF2) is preferably set to be −11.000.
Preferably, the zoom optical system ZLI according to the 6th embodiment satisfies the following conditional expressions (JF3) and (JF4).

−1.000<DVW/fV<1.000  (JF3)

32.000≤Wω  (JF4)

where, DVW denotes a distance between the vibration-proof lens group VR and a next lens in the wide angle end state,
fV denotes a focal length of the vibration-proof lens group VR, and
Wω denotes a half angle of view in the wide angle end state.
The conditional expression (JF3) is for setting an appropriate value of the distance between the vibration-proof lens group VR and a next lens in the wide angle end state, and the focal length of the vibration-proof lens group VR. A sufficient vibration-proof performance can be achieved when the conditional expression (JF3) is satisfied.
A value higher than the upper limit value of the conditional expression (JF3) results in the distance being large making the decentering coma aberration and the curvature of field aberration generated at the vibration-proof lens group VR difficult to correct by a lens after the vibration-proof lens group VR. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration that are difficult to correct.
To guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF3) is preferably set to be 0.700. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF3) is preferably set to be 0.400.
A value lower than the lower limit value of the conditional expression (JF3) results in the distance being large making the decentering coma aberration and the curvature of field aberration generated at the vibration-proof lens group VR difficult to correct by a lens after the vibration-proof lens group VR. Furthermore, the value results in a short focal length of the vibration-proof lens group VR, and thus leads to the vibration-proof lens group VR involving large decentering coma aberration and curvature of field aberration that are difficult to correct.
To guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF3) is preferably set to be −0.700. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF3) is preferably set to be −0.450.
The conditional expression (JF4) is for setting an appropriate value of the half angle of view in the wide angle end state. A value lower than the lower limit value of the conditional expression (JF4) results in failure to successfully correct the curvature of field aberration and distortion with a wide angle of view achieved.
To guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF4) is preferably set to be 35.000. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF4) is preferably set to be 38.000.
Preferably, the zoom optical system ZLI according to the 6th embodiment satisfies the following conditional expression (JF5).

0.010<fF/fXR<10.000  (JF5)

where, fF denotes a focal length of the focusing lens group GF, and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JF5) is for setting an appropriate value of the focal length of the focusing lens group GF and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on short-distant object can be achieved when the conditional expression (JF5) is satisfied.
A value higher than the upper limit value of the conditional expression (JF5) leads to a long focal length, that is, a large movement amount of the focusing lens group GF upon focusing, and thus results in large variation of spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the focal length of the third lens group G3 becomes short, and thus, the third lens group G3 involves a large spherical aberration.
To guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF5) is preferably set to be 8.000. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF5) is preferably set to be 6.000.
A value lower than the lower limit value of the conditional expression (JF5) leads to a short focal length of the focusing lens group GF, and thus results in the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF5) is preferably set to be 0.300. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF5) is preferably set to be 0.650.
Preferably, the zoom optical system ZLI according to the 6th embodiment satisfies the following conditional expression (JF6).

0.100<DGXR/fXR<1.500  (JF6)

where, DGXR denotes a thickness of the lens group closest to an image in the front-side lens group GX on an optical axis (the thickness of the third lens group G3 on the optical axis), and
fXR denotes a focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3).
The conditional expression (JF6) is for setting an appropriate value of the thickness of the lens group (the third lens group G3) closest to an image in the front-side lens group GX on an optical axis (that is, a distance between a lens surface closest to an object in the third lens group G3 and a lens surface closest to an image in the third lens group G3 on the optical axis) and the focal length of the lens group closest to an image in the front-side lens group GX (the focal length of the third lens group G3). A sufficient performance upon focusing on infinity as well as excellent performance in terms of brightness can be achieved when the conditional expression (JF6) is satisfied. Furthermore, downsizing of the entire system can be achieved.
A value higher than the upper limit value of the conditional expression (JF6) leads to a short focal length of the third lens group G3, and thus results in the third lens group G3 involving a large spherical aberration. Furthermore, the value leads to the third lens group G3 with a larger thickness and thus results in a longer entire length.
To guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF6) is preferably set to be 1.200. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF6) is preferably set to be 1.000.
A value lower than the lower limit value of the conditional expression (JF6) leads to a long focal length, that is, a large movement amount of the third lens group G3 upon zooming, and thus results in a large variation of the spherical aberration. Furthermore, the value leads to the third lens group G3 with a smaller thickness and thus more simple configuration, and thus results in the third lens group G3 involving a large spherical aberration.
To guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF6) is preferably set to be 0.250. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF6) is preferably set to be 0.350. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF6) is preferably set to be 0.400. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF6) is preferably set to be 0.450.
Preferably, the zoom optical system ZLI according to the 6th embodiment satisfies the following conditional expression (JF7).

2.250<TLW/ZD1<10.000  (JF7)

where, TLW denotes an entire length of the optical system in the wide angle end state, and
ZD1 denotes a movement amount of the first lens group G1 upon zooming from the wide angle end state to the telephoto end state.
The conditional expression (JF7) is for setting an appropriate value of the entire length of the optical system in the wide angle end state, and the movement amount of the first lens group G1 upon zooming from the wide angle end state to the telephoto end state. An excellent optical performance can be achieved when the conditional expression (JF7) is satisfied.
A value higher than the upper limit value of the conditional expression (JF7) leads to an arrangement with higher power in each lens group causing increase of spherical aberration and curvature of field aberration.
To guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF7) is preferably set to be 9.000. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF7) is preferably set to be 7.500. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF7) is preferably set to be 6.000. To more effectively guarantee the effects of the 6th embodiment, the upper limit value of the conditional expression (JF7) is preferably set to be 5.000.
A value lower than the lower limit value of the conditional expression (JF7) leads to a large movement amount of the first lens group G1, and thus results in a zooming involving a large variation of the curvature of field aberration.
To guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF7) is preferably set to be 2.300. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF7) is preferably set to be 2.350. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF7) is preferably set to be 2.400. To more effectively guarantee the effects of the 6th embodiment, the lower limit value of the conditional expression (JF7) is preferably set to be 2.450.
Preferably, in the zoom optical system ZLI according to the 6th embodiment, the second lens group G2 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 6th embodiment, the third lens group G3 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 6th embodiment, the fourth lens group G4 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the spherical aberration and the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 6th embodiment, the fifth lens group G5 is moved with respect to the image surface upon zooming.
The configuration can reduce variation of the curvature of field aberration upon zooming. Furthermore, efficient zooming, leading to downsizing of the optical system, can be achieved.
Preferably, in the zoom optical system ZLI according to the 6th embodiment, a part or entirety of the fifth lens group G5 is preferably the vibration-proof lens group VR.
The configuration is effective for correcting the decentering coma aberration and the curvature of field aberration upon image blur correction. The vibration-proof lens group VR as part of the fifth lens group G5 can have a small size.
As described above, the 6th embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 6th embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 6th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL2) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5, and the sixth lens group G6 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST610). The lenses are arranged in such a manner that the first lens group G1 is moved with respect to the image surface upon zooming (step ST620). The lenses are arranged in such a manner that the at least part of the fourth lens group G4 moves as the focusing lens group GF in the optical axis direction upon focusing (step ST630). The lenses are arranged in such a manner that the vibration-proof lens group VR is disposed closer to the image than the focusing lens group GF, and is configured to be movable with a displacement component in a direction orthogonal to the optical axis to correct image blur (step ST640).
In one example of the lens arrangement according to the 6th embodiment, as illustrated in FIG. 2, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, the fifth lens group G5 including the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side, and the sixth lens group G6 including the plano-convex lens L61 having a convex surface facing the object side are arranged in order from the object side. The cemented lens including the lenses L51 and L52 forming the fifth lens group G5 serves as the vibration-proof lens group VR. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 6th embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 7th embodiment is described below with reference to drawings. As illustrated in FIG. 1, a zoom optical system ZLI (ZL1) according to the 7th embodiment includes: the first lens group G1 having positive refractive power and disposed closest to an object; the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1; the intermediate lens group GM disposed more on the image surface side than the front-side lens group; and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM. The front-side lens group GX includes a lens group having negative refractive power. At least part of the intermediate lens group GM is the focusing lens group GF. The focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing. Upon zooming, the first lens group G1 is moved with respect to an image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed. An air lens having a meniscus shape is formed of: a lens surface on the image surface side of a lens closest to the image surface in lenses disposed to the object side of the focusing lens group GF; and a lens surface closest to an object in the focusing lens group GF.
The air lens may have the meniscus shape with the convex surface facing the object side, or with the convex surface facing the image surface side.
The configuration including the positive first lens group G1, the front-side lens group GX including a negative lens group, the intermediate lens group GM including the positive focusing lens group GF, and the rear-side lens group GR, and performing the zooming by changing a distance between the lens groups can have a small size and achieve an excellent optical performance. The configuration in which the first lens group G1 is moved with respect to the image surface upon zooming can achieve efficient zooming, and can achieve further downsizing and a higher performance (reduction of the curvature of field aberration upon zooming). When the zooming is performed with the first lens group G1 fixed, the second lens group G2 and the groups thereafter need to be largely moved, rendering downsizing difficult. The configuration of performing focusing by using at least part of the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX can reduce variation of the image magnification, the spherical aberration, and the curvature of field aberration upon focusing. The configuration in which the air lens disposed to the object side of the focusing lens group GF (movement direction upon focusing on a short distant object) has the meniscus shape can reduce the variation of the curvature of field aberration.
For example, in Example 1 described below corresponding to the configuration according to the 7th embodiment that includes the positive first lens group G1, the negative second lens group G2, the positive third lens group G3, the positive fourth lens group G4, and the fifth lens group G5 arranged in order from the object side, and performs focusing with the entire fourth lens group G4, the second and the third lens groups G2 and G3 correspond to the front-side lens group GX, the fourth lens group G4 corresponds to the intermediate lens group GM, and the fifth lens group G5 corresponds to the rear-side lens group GR.
For example, in Example 14 described below corresponding to the configuration according to the 7th embodiment that includes the positive first lens group G1, the negative second lens group G2, the positive third lens group G3, the negative fourth lens group G4, and the fifth lens group G5 arranged in order from the object side, and performs focusing with part of the third lens group G3, the second lens group G2 corresponds to the front-side lens group GX, the third lens group G3 corresponds to the intermediate lens group GM, and the fourth and the fifth lens groups G4 and G5 correspond to the rear-side lens group GR.
It is to be noted that the front-side lens group GX in the 7th embodiment is not limited to the configuration described above, and the following configuration may be employed.
For example, in the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when focusing is performed by using the entire fifth lens group with the negative second lens group divided into two lens groups, the second to the fourth lens groups correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when focusing is performed by using the entire fifth lens group with the positive first lens group divided into two lens groups, the image side of the first lens group to the fourth lens group correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when focusing is performed by using the entire fifth lens group with another lens group added between the second lens group and the third lens group, the second to the fourth lens groups, including the added other lens group, correspond to the front-side lens group.
The zoom optical system ZLI according to the 7th embodiment with the configuration described above satisfies the following conditional expression (JG1).

−0.400<βFt<0.400  (JG1)

where, βFt: lateral magnification of the focusing lens group GF in the telephoto end state.
The conditional expression (JG1) is for setting an appropriate value of the lateral magnification of the focusing lens group GF in the telephoto end state. A sufficient performance upon focusing on short-distant object can be guaranteed in the telephoto end state upon focusing when the conditional expression (JG1) is satisfied.
A value higher than the upper limit value of the conditional expression (JG1) results in large variation of the spherical aberration in the telephoto end state upon focusing.
To guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG1) is preferably set to be 0.300. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG1) is preferably set to be 0.200. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG1) is preferably set to be 0.150. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG1) is preferably set to be 0.100.
A value lower than the lower limit value of the conditional expression (JG1) leads to a large movement amount of the focusing lens group GF upon focusing in the telephoto end state, and thus results in large variation of spherical aberration and curvature of field aberration.
To guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG1) is preferably set to be −0.300. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG1) is preferably set to be −0.200. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG1) is preferably set to be −0.150. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG1) is preferably set to be −0.100.
In the zoom optical system ZLI according to the 7th embodiment, a lens in the intermediate lens group GM may be the same as a lens in the focusing lens group GF.
In this configuration, the distance between the focusing lens group GF (=intermediate lens group GM) and the adjacent lens groups is changed upon zooming, whereby aberration reduction due to zooming can be prevented.
In the zoom optical system ZLI according to the 7th embodiment, part of the intermediate lens group GM may serve as the focusing lens group GF.
In this configuration, the focusing lens group GF and the other lens in the intermediate lens group GM (the lens on the front side or the image side of the focusing lens group GF) can integrally move upon zooming, whereby a simple barrel configuration can be achieved.
The zoom optical system ZLI according to the 7th embodiment preferably includes the vibration-proof lens group VR that is disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface, and can move with a displacement component in the direction orthogonal to the optical axis.
In this configuration, the vibration-proof lens group VR can be achieved that is small and can successfully correct the variation of the curvature of field aberration upon decentering, with an appropriate image shift feeling upon decentering.
In the zoom optical system ZLI according to the 7th embodiment lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be the same as a lens in the vibration-proof lens group VR.
With this configuration, downsizing can be achieved with the image blur correction performance maintained.
In the zoom optical system ZLI according to the 7th embodiment part of the lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be a lens in the vibration-proof lens group VR.
With this configuration, the optical performance can be improved with the lens other than the vibration-proof lens group VR disposed between the intermediate lens group GM and the lens closest to the image surface. The distance between lenses disposed closer to the image surface than the intermediate lens group GM may be appropriately changed upon zooming.
Preferably, in the zoom optical system ZLI according to the 7th embodiment, a distance between the lens closest to the image surface in the lenses disposed to the object side of the focusing lens group GF and the focusing lens group GF may be reduced and then increased, upon zooming from the wide angle end state to the telephoto end state.
With this configuration, successful correction can be performed to prevent excessive curvature of field upon zooming.
Preferably, the zoom optical system ZLI according to the 7th embodiment satisfies the following conditional expression (JG2).

1.250<(rB+rA)/(rB−rA)<10.000  (JG2)

where, rA denotes a radius of curvature of a lens surface facing a lens surface closest to an object in the focusing lens group GF with a distance in between, and
rB denotes a radius of curvature of the lens surface closest to an object in the focusing lens group GF.
The conditional expression (JG2) is for setting an appropriate shape of the air lens disposed to the object side of the focusing lens group GF (direction of movement upon focusing on a short distant object). The air lens has the meniscus shape and thus a sufficient performance upon focusing on short-distant object can be obtained on or outside the axis when the conditional expression (JG2) is satisfied.
A value higher than the upper limit value of the conditional expression (JG2) leads to rA that is too large relative to rB, and thus results in a larger curvature of field aberration at the lens surface closest to an object in the focusing lens group GF than that at the lens surface facing the lens surface closest to an object in the focusing lens group GF with the distance in between. Thus, variation of the curvature of field aberration upon focusing on infinity and upon focusing on a short distant object becomes large.
To guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG2) is preferably set to be 6.670. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG2) is preferably set to be 5.000. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG2) is preferably set to be 4.000.
A value lower than the lower limit value of the conditional expression (JG2) leads to rA that is too small relative to rB. Thus, a curvature of field aberration at the lens surface facing the lens surface closest to an object in the focusing lens group GF with a distance in between overwhelms the correction capacity of the lens closest to an object in the focusing lens group GF, and thus results in large variation of curvature of field aberration upon focusing on infinity and upon focusing on a short distant object.
To guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG2) is preferably set to be 1.540. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG2) is preferably set to be 2.000. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG2) is preferably set to be 2.500.
Preferably, the zoom optical system ZLI according to the 7th embodiment satisfies the following conditional expression (JG3).

0.000<βFw<0.800  (JG3)

where, βFW denotes lateral magnification of the focusing lens group GF in the wide angle end state.
The conditional expression (JG3) is for setting an appropriate range of the magnification of the focusing lens group GF in the wide angle end state. When the conditional expression (JG3) is satisfied, the magnification related to the focusing lens group GF is appropriately set even when a sensor size is large, and thus the variation of aberration can be successfully reduced.
A value higher than an upper limit value of the conditional expression (JG3) results in a successful reduction of the movement amount of the focusing lens group GF but also results in failure to successfully correct variation of the spherical aberration upon focusing on a short distant object.
To guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG3) is preferably set to be 0.600. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG3) is preferably set to be 0.400. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG3) is preferably set to be 0.360. To more effectively guarantee the effects of the 7th embodiment, the upper limit value of the conditional expression (JG3) is preferably set to be 0.350.
A value lower than the lower limit value of the conditional expression (JG3) leads to a large movement amount of the focusing lens group GF, and thus results in a large optical system, and failure to successfully correct variation of the spherical aberration and the curvature of field aberration upon focusing.
To guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG3) is preferably set to be 0.020. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG3) is preferably set to be 0.040. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG3) is preferably set to be 0.060. To more effectively guarantee the effects of the 7th embodiment, the lower limit value of the conditional expression (JG3) is preferably set to be 0.080.
As described above, the 7th embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 7th embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 7th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL1) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power and disposed closest to an object, the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1, the intermediate lens group GM disposed more on the image surface side than the front-side lens group, and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM are arranged in a barrel (step ST710). The lenses are arranged in such a manner that the front-side lens group GX includes a lens group with negative refractive power (step ST720). The lenses are arranged in such a manner that at least part of the intermediate lens group GM serves as the focusing lens group GF, and that the focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing (step ST730). The lenses are arranged in such a manner that upon zooming, the first lens group G1 is moved with respect to an image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed (step ST740). The lenses are arranged in such a manner that an air lens having a meniscus shape is formed of: a lens surface on the side of the image surface of a lens closest to the image surface in lenses disposed to the object side of the focusing lens group GF; and a lens surface closest to an object in the focusing lens group GF (step ST750). The lenses are arranged to satisfy at least the following conditional expression (JG1) in the conditional expressions described above (step ST760).
In one example of the lens arrangement according to the 7th embodiment, as illustrated in FIG. 1, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the negative meniscus lens L22 having a concave surface facing the object side, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, and the fifth lens group G5 including the cemented lens including a positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 7th embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 8th embodiment is described below with reference to drawings. As illustrated in FIG. 1, a zoom optical system ZLI (ZL1) according to the 8th embodiment includes: the first lens group G1 having positive refractive power and disposed closest to an object; the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1; the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX; and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM. The front-side lens group GX includes a lens group having negative refractive power. At least part of the intermediate lens group GM is the focusing lens group GF. The focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing. Upon zooming, the first lens group G1, the at least one front-side lens group GX, the intermediate lens group GM, the at least one rear-side lens group GR move with respect to the image surface, and the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed.
The configuration of including the positive first lens group G1, the front-side lens group GX including a negative lens group, the intermediate lens group GM including the positive focusing lens group GF, and the rear-side lens group GR, and performing the zooming by changing a distance between the lens groups can have a small size and achieve an excellent optical performance. The configuration in which the first lens group G1, the front-side lens group GX, the intermediate lens group GM, the rear-side lens group GR move with respect to the image surface upon zooming can achieve efficient zooming, and can achieve further downsizing and a higher performance (reduction of the curvature of field aberration upon zooming). The configuration of performing focusing by using at least part of the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX can reduce variation of the image magnification, the spherical aberration, and the curvature of field aberration upon focusing.
For example, in Example 1 described below corresponding to the configuration according to the 8th embodiment that includes the positive first lens group G1, the negative second lens group G2, the positive third lens group G3, the positive fourth lens group G4, and the fifth lens group G5 arranged in order from the object side, and performs focusing with the entire fourth lens group G4, the second and the third lens groups G2 and G3 correspond to the front-side lens group GX, the fourth lens group G4 corresponds to the intermediate lens group GM, and the fifth lens group G5 corresponds to the rear-side lens group GR.
It is to be noted that the front-side lens group GX in the 8th embodiment is not limited to the configuration described above, and the following configuration may be employed.
For example, in the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when the focusing is performed by using the entire fifth lens group with the negative second lens group divided into two lens groups, the second to the fourth lens groups correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when focusing is performed by using the entire fifth lens group with the positive first lens group divided into two lens groups, the image side of the first lens group to the fourth lens group correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when the focusing is performed by using the entire fifth lens group with another lens group added between the second lens group and the third lens group, the second to the fourth lens groups, including the added other lens group, correspond to the front-side lens group.
The zoom optical system ZLI according to the 8th embodiment with the configuration described above satisfies the following conditional expression (JH1).

1.490<(rB+rA)/(rB−rA)<3.570  (JH1)

where rA denotes a radius of curvature of a lens surface facing a lens surface closest to an object in the focusing lens group GF with a distance in between, and
rB denotes a radius of curvature of the lens surface closest to an object in the focusing lens group GF.
The conditional expression (JH1) is for setting an appropriate shape of the air lens disposed to the object side of the focusing lens group GF (direction of movement upon focusing on a short distant object). The air lens has the meniscus shape and thus a sufficient performance upon focusing on short-distant object can be obtained on or outside the axis when the conditional expression (JH1) is satisfied.
A value higher than the upper limit value of the conditional expression (JH1) leads to rA that is too large relative to rB, and thus results in a larger curvature of field aberration at the lens surface closest to an object in the focusing lens group GF than that at the lens surface facing the lens surface closest to an object in the focusing lens group GF with a distance in between. Thus, variation of the curvature of field aberration upon focusing on infinity and upon focusing on a short distant object becomes large.
To guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH1) is preferably set to be 3.509. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH1) is preferably set to be 3.390. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH1) is preferably set to be 3.279.
A value lower than the lower limit value of the conditional expression (JH1) leads to rA that is too small relative to rB. Thus, a curvature of field aberration at the lens surface facing the lens surface closest to an object in the focusing lens group GF with a distance in between overwhelms the correction capacity of the lens surface closest to an object in the focusing lens group GF, and thus results in large variation of curvature of field aberration upon focusing on infinity and upon focusing on a short distant object.
To guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH1) is preferably set to be 1.667. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH1) is preferably set to be 2.000. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH1) is preferably set to be 2.500.
In the zoom optical system ZLI according to the 8th embodiment, a lens in the intermediate lens group GM may be the same as a lens in the focusing lens group GF.
In this configuration, the distance between the focusing lens group GF (=intermediate lens group GM) and the adjacent lens groups is changed upon zooming, whereby aberration reduction due to zooming can be prevented.
In the zoom optical system ZLI according to the 8th embodiment, part of the intermediate lens group GM may serve as the focusing lens group GF.
In this configuration, the focusing lens group GF and the other lens in the intermediate lens group GM (the lens on the front side or the image side of the focusing lens group GF) can integrally move upon zooming, whereby a simple barrel configuration can be achieved.
The zoom optical system ZLI according to the 8th embodiment preferably includes the vibration-proof lens group VR that is disposed between the focusing lens group GF and the lens closest to the image surface, and can move with a displacement component in the direction orthogonal to the optical axis.
In this configuration, the vibration-proof lens group VR can be achieved that is small and can successfully correct the variation of the curvature of field aberration upon decentering, with an appropriate image shift feeling upon decentering.
In the zoom optical system ZLI according to the 8th embodiment lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be the same as a lens in the vibration-proof lens group VR.
With this configuration, downsizing can be achieved with the image blur correction performance maintained.
In the zoom optical system ZLI according to the 8th embodiment part of the lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be a lens in the vibration-proof lens group VR.
With this configuration, the optical performance can be improved with the lens other than the vibration-proof lens group VR disposed between the intermediate lens group GM and the lens closest to the image surface. The distance between lenses disposed closer to the image surface than the intermediate lens group GM may be appropriately changed upon zooming.
Preferably, in the zoom optical system ZLI according to the 8th embodiment, a distance between the lens closest to the image surface in the lenses disposed to the object side of the focusing lens group GF and the focusing lens group GF may be reduced and then increased, upon zooming from the wide angle end state to the telephoto end state.
With this configuration, successful correction can be performed to prevent excessive curvature of field upon zooming.
Preferably, the zoom optical system ZLI according to the 8th embodiment satisfies the following conditional expression (JH2).

−0.500<(rC+rB)/(rC−rB)<0.500  (JH2)

where, rC: a radius of curvature of the lens closest to the image surface in the focusing lens group GF.
The conditional expression (JH2) is for setting an appropriate shape of the focusing lens group GF. A sufficient performance upon focusing on short-distant object as well as downsizing can be achieved with the movement amount of the focusing lens group GF reduced, when the conditional expression (JH2) is satisfied.
A value higher than the upper limit value of the conditional expression (JH2) leads to the radius of curvature rC of the lens surface closest to the image surface that is too large relative to the radius of curvature rB of the lens surface closest to an object in the focusing lens group GF, and thus results in a large variation of the curvature of field aberration upon focusing on infinity and focusing on a short distant object.
To guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH2) is preferably set to be 0.300. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH2) is preferably set to be 0.200. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH2) is preferably set to be 0.100. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH2) is preferably set to be 0.050.
A value lower than the lower limit value of the conditional expression (JH2) leads to the radius of curvature rC of the lens surface closest to the image surface that is too small relative to the radius of curvature rB of the lens surface closest to an object in the focusing lens group GF, and thus results in a large variation of the spherical aberration upon focusing on infinity and focusing on a short distant object.
To guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH2) is preferably set to be −0.400. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH2) is preferably set to be −0.350. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH2) is preferably set to be −0.300. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH2) is preferably set to be −0.250.
In the zoom optical system ZLI according to the 8th embodiment, the focusing lens group GF preferably includes a negative lens having a meniscus shape with the concave surface facing the object side.
With this configuration, the curvature of field aberration and coma aberration can be successfully corrected.
Preferably, the zoom optical system ZLI according to the 8th embodiment satisfies the following conditional expression (JH3).

0.010<|fF/fXR|<10.000  (JH3)

where, fF denotes a focal length of the focusing lens group GF, and
fXR denotes a focal length of the lens group closest to the image surface in the front-side lens group GX.
The conditional expression (JH3) is for setting an appropriate value of the focal length of the focusing lens group GF with respect to the focal length of the lens group facing the object side of the focusing lens group GF. An appropriate movement amount of the focusing lens group GF can be obtained with the short distance performance maintained, when the conditional expression (JH3) is satisfied.
A value higher than the upper limit value of the conditional expression (JH3) results in a long focal length fF, that is, a large movement amount of the focusing lens group GF upon focusing, leading to large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the value results in a short focal length of the lens group facing the object side of the focusing lens group GF, and thus leads to the lens group involving a large spherical aberration.
To guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH3) is preferably set to be 8.000. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH3) is preferably set to be 6.000.
A value lower than a lower limit value of the conditional expression (JH3) results in a short focal length of the focusing lens group GF, and thus leads to the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH3) is preferably set to be 0.300. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH3) is preferably set to be 0.650.
Preferably, the zoom optical system ZLI according to the 8th embodiment satisfies the following conditional expression (JH4).

0.000<βFw<0.800  (JH4)

where, βFw denotes lateral magnification of the focusing lens group GF in the wide angle end state.
The conditional expression (JH4) is for setting an appropriate range of the magnification of the focusing lens group GF in the wide angle end state. When the conditional expression (JH4) is satisfied, the magnification related to the focusing lens group GF is appropriately set even when a sensor size is large, and thus the variation of aberration can be successfully reduced.
A value higher than an upper limit value of the conditional expression (JH4) results in a successful reduction of the movement amount of the focusing lens group GF but also results in failure to successfully correct variation of the spherical aberration upon focusing on a short distant object.
To guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH4) is preferably set to be 0.600. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH4) is preferably set to be 0.400. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH4) is preferably set to be 0.360. To more effectively guarantee the effects of the 8th embodiment, the upper limit value of the conditional expression (JH4) is preferably set to be 0.350.
A value lower than the lower limit value of the conditional expression (JH4) leads to a large movement amount of the focusing lens group GF, and thus results in a large optical system, and failure to successfully correct variation of the spherical aberration and the curvature of field aberration upon focusing.
To guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH4) is preferably set to be 0.020. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH4) is preferably set to be 0.040. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH4) is preferably set to be 0.060. To more effectively guarantee the effects of the 8th embodiment, the lower limit value of the conditional expression (JH4) is preferably set to be 0.080.
As described above, the 8th embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 8th embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 8th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL1) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power and disposed closest to an object, the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1, the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX, and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM are arranged in a barrel (step ST810). The lenses are arranged in such a manner that the front-side lens group GX includes a lens group with negative refractive power (step ST820). The lenses are arranged in such a manner that at least part of the intermediate lens group GM serves as the focusing lens group GF, and that the focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing (step ST830). The lenses are arranged in such a manner that upon zooming, the first lens group G1, the at least one front-side lens group GX, the intermediate lens group GM, the at least one rear-side lens group GR move with respect to the image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed (step ST840). The lenses are arranged to satisfy at least the conditional expression (JH1) in the conditional expressions described above (step ST850).
In one example of the lens arrangement according to the 8th embodiment, as illustrated in FIG. 1, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the negative meniscus lens L22 having a concave surface facing the object side, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, and the fifth lens group G5 including the cemented lens including a positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 8th embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 9th embodiment is described below with reference to drawings. As illustrated in FIG. 7, a zoom optical system ZLI (ZL7) according to the 9th embodiment includes: the first lens group G1 having positive refractive power and disposed closest to an object; the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1; the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX; and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM. The front-side lens group GX includes a lens group having negative refractive power. At least part of the intermediate lens group GM is the focusing lens group GF. The focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing. The vibration-proof lens group VR is disposed between the focusing lens group GF and a lens closest to the image surface, and the vibration-proof lens group VR can move with a displacement component in the direction orthogonal to the optical axis. Upon zooming, the first lens group G1 is moved with respect to an image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed. A lens surface closest to an object in the focusing lens group GF is convex toward the object side.
The configuration including the positive first lens group G1, the front-side lens group GX including a negative lens group, the intermediate lens group GM including the positive focusing lens group GF, and the vibration-proof lens group VR, and performing the zooming by changing a distance between the lens groups can have a small size and achieve an excellent optical performance. The configuration in which the first lens group G1 is moved with respect to the image surface upon zooming can achieve efficient zooming, and can achieve further downsizing and a higher performance (reduction of the curvature of field aberration upon zooming). The configuration of performing focusing by using at least part of the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX can reduce variation of the image magnification, the spherical aberration, and the curvature of field aberration upon focusing. The configuration in which the vibration-proof lens group VR is more on the image side than the focusing lens group GF and thus is not the final lens can achieve downsizing and successful image blur correction. The lens surface closest to an object in the focusing lens group GF is convex toward the object side (that is, the air lens disposed to the object side of the focusing lens group GF (the direction of movement upon focusing on a short distant object) has a concaved shape). Thus, the variation of the spherical aberration and the coma aberration upon focusing can be reduced.
For example, in Example 7 described below corresponding to the configuration according to the 9th embodiment that includes the positive first lens group G1, the negative second lens group G2, the positive third lens group G3, the positive fourth lens group G4, and the fifth lens group G5 arranged in order from the object side, and performs focusing with the entire fourth lens group G4, the second and the third lens groups G2 and G3 correspond to the front-side lens group GX, the fourth lens group G4 corresponds to the intermediate lens group GM, and the lens L51 of the fifth lens group G5 corresponds to the vibration-proof lens group VR.
It is to be noted that the front-side lens group GX in the 9th embodiment is not limited to the configuration described above, and the following configuration may be employed.
For example, in the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 7, when focusing is performed by using the entire fifth lens group with the negative second lens group divided into two lens groups, the second to the fourth lens groups correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 7, when focusing is performed by using the entire fifth lens group with the positive first lens group divided into two lens groups, the image side of the first lens group to the fourth lens group correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 7, when focusing is performed by using the entire fifth lens group with another lens group added between the second lens group and the third lens group, the second to the fourth lens groups, including the added other lens group, correspond to the front-side lens group.
The zoom optical system ZLI according to the 9th embodiment with the configuration described above satisfies the following conditional expressions (JI1) and (JI2).

0.000<(rB+rA)/(rB−rA)<1.000  (JI1)

0.000<(rC+rB)/(rC−rB)<10.000  (JI2)

where, rA denotes a radius of curvature of a lens surface facing a lens surface closest to an object in the focusing lens group GF with a distance in between, and
rB denotes a radius of curvature of the lens surface closest to an object in the focusing lens group GF, and
rC denotes a radius of curvature of the lens surface closest to the image surface in the focusing lens group GF.
The conditional expression (JI1) is for setting an appropriate shape of the air lens disposed to the object side of the focusing lens group GF (direction of movement upon focusing on a short distant object). The air lens has the concave shape and thus a sufficient performance upon focusing on short-distant object can be obtained on or outside the axis when the conditional expression (JI1) is satisfied.
A value exceeds the upper limit value of the conditional expression (JI1) leads to rA that is too small relative to rB. Thus, a curvature of field aberration at the lens surface closest to the image surface in the third lens group G3 overwhelms the correction capacity of the lens surface closest to an object in the fourth lens group G4, and thus results in large variation of curvature of field aberration upon focusing on infinity and upon focusing on a short distant object.
To guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI1) is preferably set to be 0.800. To more effectively guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI1) is preferably set to be 0.600. To more effectively guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI1) is preferably set to be 0.500. To more effectively guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI1) is preferably set to be 0.400.
A value lower than the lower limit value of the conditional expression (JI1) leads to rA that is too large relative to rB. Thus, a curvature of field aberration at the lens surface closest to the image surface in the third lens group G3 overwhelms the curvature of field aberration at the lens surface closest to an object in the fourth lens group G4, and thus results in large variation of curvature of field aberration upon focusing on infinity and upon focusing on a short distant object.
To guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI1) is preferably set to be 0.040. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI1) is preferably set to be 0.060. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI1) is preferably set to be 0.080. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI1) is preferably set to be 0.100.
The conditional expression (JI2) is for setting an appropriate shape of the focusing lens group GF. A sufficient performance upon focusing on short-distant object as well as downsizing can be achieved when the conditional expression (JI2) is satisfied.
A value higher than the upper limit value of the conditional expression (JI2) leads to an excessively small difference between the radius of curvature rB of the lens surface closest to an object in the focusing lens group GF relative to the radius of curvature rC of the lens surface closest to the image surface, and thus results in a large variation of the curvature of field aberration. When the values of the radius of curvature rB and rC is close, the focusing lens group GF is difficult to have power, and thus the movement amount of the focusing lens group GF increases.
To guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI2) is preferably set to be 8.000. To more effectively guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI2) is preferably set to be 6.000. To more effectively guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI2) is preferably set to be 5.000. To more effectively guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI2) is preferably set to be 4.000.
A value lower than the lower limit value of the conditional expression (JI2) leads to an excessively large difference between the radius of curvature rB of the lens surface closest to an object in the focusing lens group GF relative to the radius of curvature rC of the lens surface closest to the image surface, and thus results in a large variation of the spherical aberration.
To guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI2) is preferably set to be 0.200. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI2) is preferably set to be 0.300. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI2) is preferably set to be 0.400. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI2) is preferably set to be 0.500.
In the zoom optical system ZLI according to the 9th embodiment, a lens in the intermediate lens group GM may be the same as a lens in the focusing lens group GF.
In this configuration, the distance between the focusing lens group GF (=intermediate lens group GM) and the adjacent lens groups is changed upon zooming, whereby aberration reduction due to zooming can be prevented.
In the zoom optical system ZLI according to the 9th embodiment, part of the intermediate lens group GM may serve as the focusing lens group GF.
In this configuration, the focusing lens group GF and the other lens in the intermediate lens group GM (the lens on the front side or the image side of the focusing lens group GF) can integrally move upon zooming, whereby a simple barrel configuration can be achieved.
In the zoom optical system ZLI according to the 9th embodiment lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be the same as a lens in the vibration-proof lens group VR.
With this configuration, downsizing can be achieved with the image blur correction performance maintained.
In the zoom optical system ZLI according to the 9th embodiment part of the lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be a lens in the vibration-proof lens group VR.
With this configuration, the optical performance can be improved with the lens other than the vibration-proof lens group VR disposed between the intermediate lens group GM and the lens closest to the image surface. The distance between lenses disposed closer to the image surface than the intermediate lens group GM may be appropriately changed upon zooming.
Preferably, in the zoom optical system ZLI according to the 9th embodiment, a distance between the lens closest to the image surface in the lenses disposed to the object side of the focusing lens group GF and the focusing lens group GF may be reduced and then increased, upon zooming from the wide angle end state to the telephoto end state.
With this configuration, successful correction can be performed to prevent excessive curvature of field upon zooming.
Preferably, the zoom optical system ZLI according to the 9th embodiment satisfies the following conditional expression (JI3).

0.010<|fF/fXR|<10.000  (JI3)

where, fF denotes a focal length of the focusing lens group GF, and
fXR denotes a focal length of the lens group closest to the image surface in the front-side lens group GX.
The conditional expression (JI3) is for setting an appropriate value of the focal length of the focusing lens group GF with respect to the focal length of the lens group facing the object side of the focusing lens group GF. An appropriate movement amount of the focusing lens group GF can be obtained with the short distance performance maintained, when the conditional expression (JI3) is satisfied.
A value higher than the upper limit value of the conditional expression (JI3) results in a long focal length fF, that is, a large movement amount of the focusing lens group GF upon focusing, leading to large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the value results in a short focal length of the lens group facing the object side of the focusing lens group GF, and thus leads to the focusing lens group involving a large spherical aberration.
To guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI3) is preferably set to be 8.000. To more effectively guarantee the effects of the 9th embodiment, the upper limit value of the conditional expression (JI3) is preferably set to be 6.000.
A value lower than a lower limit value of the conditional expression (JI3) results in a short focal length of the focusing lens group GF, and thus leads to the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI3) is preferably set to be 0.300. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI3) is preferably set to be 0.650.
Preferably, in the zoom optical system ZLI according to the 9th embodiment, the focusing lens group GF includes at least one positive lens that satisfies the following conditional expression (JI4).

υdp>55.000  (JI4)

where, υdp denotes Abbe number on the d-line of the positive lens.
The conditional expression (JI4) is for setting an appropriate value of the Abbe number of the positive lens in the focusing lens group GF. Variation of a chromatic aberration upon focusing can be successfully reduced when the conditional expression (JI4) is satisfied.
A value higher than an upper limit value of the conditional expression (JI4) results in the color aberration at the focusing lens group GF that is too large to correct.
To guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI4) is preferably set to be 60.000. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI4) is preferably set to be 65.000. To more effectively guarantee the effects of the 9th embodiment, the lower limit value of the conditional expression (JI4) is preferably set to be 70.000.
As described above, the 9th embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 9th embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 9th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL7) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power and disposed closest to an object, the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1, the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX, and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM are arranged in a barrel (step ST910). The lenses are arranged in such a manner that the front-side lens group GX includes a lens group with negative refractive power (step ST920). The lenses are arranged in such a manner that at least part of the intermediate lens group GM serves as the focusing lens group GF, and that the focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing (step ST930). The lenses are arranged in such a manner that the vibration-proof lens group VR is disposed between the focusing lens group GF and a lens closest to the image surface, and the vibration-proof lens group VR can move with a displacement component in the direction orthogonal to the optical axis (step ST940). The lenses are arranged in such a manner that upon zooming, the first lens group G1 is moved with respect to an image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed (step ST950). The lenses are arranged in such a manner that the lens surface closest to an object in the focusing lens group GF is convex toward the object side (step ST960). The lenses are arranged to satisfy at least the conditional expressions (JI1) and (JI2) in the conditional expressions described above (step ST970).
In one example of the lens arrangement according to the 9th embodiment, as illustrated in FIG. 7, the first lens group G1 including a cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and a positive meniscus lens L12 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, and a positive meniscus lens L23 having a convex surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, a cemented lens including a positive meniscus lens L32 having a convex surface facing the object side and a negative meniscus lens L33 having a concave surface facing the image surface side, and a cemented lens including a negative meniscus lens L34 having a concave surface facing the image surface side and the biconvex lens L35, the fourth lens group G4 including a positive meniscus lens L41 having a convex surface facing the object side, and the fifth lens group G5 including a biconcave lens L51 and a plano-convex lens L52 having a convex surface facing the object side are arranged in order from the object side. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 9th embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 10th embodiment is described below with reference to drawings. As illustrated in FIG. 1, a zoom optical system ZLI (ZL1) according to the 10th embodiment includes: the first lens group G1 having positive refractive power and disposed closest to an object; the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1; the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX; and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM. The front-side lens group GX includes a lens group having negative refractive power. At least part of the intermediate lens group GM is the focusing lens group GF. The focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing. The vibration-proof lens group VR is disposed between the focusing lens group GF and a lens closest to the image surface, and the vibration-proof lens group VR can move with a displacement component in the direction orthogonal to the optical axis. Upon zooming, the first lens group G1 is moved with respect to an image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed.
The configuration including the positive first lens group G1, the front-side lens group GX including a negative lens group, the intermediate lens group GM including the positive focusing lens group GF, and the vibration-proof lens group VR, and performing the zooming by changing a distance between the lens groups can have a small size and achieve an excellent optical performance. The configuration in which the first lens group G1 is moved with respect to the image surface upon zooming can achieve efficient zooming, and can achieve further downsizing and a higher performance (reduction of the curvature of field aberration upon zooming). The configuration of performing focusing by using at least part of the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX can reduce variation of the image magnification, the spherical aberration, and the curvature of field aberration upon focusing. The configuration in which the vibration-proof lens group VR is more on the image side than the focusing lens group GF and thus is not the final lens can achieve downsizing and successful image blur correction.
For example, in Example 1 described below corresponding to the configuration according to the 10th embodiment that includes the positive first lens group G1, the negative second lens group G2, the positive third lens group G3, the positive fourth lens group G4, and the fifth lens group G5 arranged in order from the object side, and performs focusing with the entire fourth lens group G4, the second and the third lens groups G2 and G3 correspond to the front-side lens group GX, the fourth lens group G4 corresponds to the intermediate lens group GM, and the cemented lens including the lenses L51 and L52 of the fifth lens group G5 corresponds to the vibration-proof lens group VR.
For example, in Example 14 described below that includes the positive first lens group G1, the negative second lens group G2, the positive third lens group G3, the negative fourth lens group G4, and the fifth lens group G5 arranged in order from the object side and performs focusing with a part of the third lens group G3, the second lens group G2 corresponds to the front-side lens group GX, the third lens group G3 corresponds to the intermediate lens group GM, and the fourth lens group G4 corresponds to the vibration-proof lens group VR.
It is to be noted that the front-side lens group GX in the 10th embodiment is not limited to the configuration described above, and the following configuration may be employed.
For example, in the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when focusing is performed by using the entire fifth lens group with the negative second lens group divided into two lens groups, the second to the fourth lens groups correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when focusing is performed by using the entire fifth lens group with the positive first lens group divided into two lens groups, the image side of the first lens group to the fourth lens group correspond to the front-side lens group.
In the configuration including the positive first lens group, the negative second lens group, the positive third lens group, the positive fourth lens group, and the fifth lens group arranged in order from the object side as in Example 1, when focusing is performed by using the entire fifth lens group with another lens group added between the second lens group and the third lens group, the second to the fourth lens groups, including the added other lens group, correspond to the front-side lens group.
The zoom optical system ZLI according to the 10th embodiment with the configuration described above satisfies the following conditional expression (JJ1).

1.050<(rB+rA)/(rB−rA)  (JJ1)

where, rA denotes a radius of curvature of a lens surface facing a lens surface closest to an object in the focusing lens group GF with a distance in between, and
rB denotes a radius of curvature of the lens surface closest to an object in the focusing lens group GF.
The conditional expression (JJ1) is for setting an appropriate shape of the air lens disposed to the object side of the focusing lens group GF (direction of movement upon focusing on a short distant object). The air lens has the meniscus shape and thus a sufficient performance upon focusing on short-distant object can be obtained on or outside the axis when the conditional expression (JJ1) is satisfied.
To guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ1) is preferably set to be 10.000. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ1) is preferably set to be 6.667. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ1) is preferably set to be 5.000.
A value higher than the upper limit value of the conditional expression (JJ1) leads to rA that is too large relative to rB, resulting in a larger curvature of field aberration at the lens surface closest to an object in the focusing lens group GF than that at the lens surface facing the lens surface closest to an object in the focusing lens group GF with a distance in between. Thus, variation of the curvature of field aberration upon focusing on infinity and upon focusing on a short distant object becomes large.
A value lower than the lower limit value of the conditional expression (JJ1) leads to rA that is too small relative to rB. Thus, a curvature of field aberration at the lens surface facing the lens surface closest to an object in the focusing lens group GF with a distance in between overwhelms the correction capacity of the lens surface closest to an object in the focusing lens group GF, resulting in large variation of curvature of field aberration upon focusing on infinity and upon focusing on a short distant object.
To guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ1) is preferably set to be 1.429. To more effectively guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ1) is preferably set to be 1.667. To more effectively guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ1) is preferably set to be 2.000.
In the zoom, optical system ZLI according to the 10th embodiment, a lens in the intermediate lens group GM may be the same as a lens in the focusing lens group GF.
In this configuration, the distance between the focusing lens group GF (=intermediate lens group GM) and the adjacent lens groups is changed upon zooming, whereby aberration reduction due to zooming can be prevented.
In the zoom, optical system ZLI according to the 10th embodiment, part of the intermediate lens group GM may serve as the focusing lens group GF.
In this configuration, the focusing lens group GF and the other lens in the intermediate lens group GM (the lens on the front side or the image side of the focusing lens group GF) can integrally move upon zooming, whereby a simple barrel configuration can be achieved.
In the zoom optical system ZLI according to the 10th embodiment, lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be the same as a lens in the vibration-proof lens group VR.
With this configuration, downsizing can be achieved with the image blur correction performance maintained.
In the zoom optical system ZLI according to the 10th embodiment, part of the lenses disposed between the focusing lens group GF (=intermediate lens group GM) and the lens closest to the image surface may be a lens in the vibration-proof lens group VR.
With this configuration, the optical performance can be improved with the lens other than the vibration-proof lens group VR disposed between the intermediate lens group GM and the lens closest to the image surface. The distance between lenses disposed closer to the image surface than the intermediate lens group GM may be appropriately changed upon zooming.
Preferably, in the zoom optical system ZLI according to the 10th embodiment, a distance between the lens closest to the image surface in the lenses disposed to the object side of the focusing lens group GF and the focusing lens group GF may be reduced and then increased, upon zooming from the wide angle end state to the telephoto end state.
With this configuration, successful correction can be performed to prevent excessive curvature of field upon zooming.
Preferably, the zoom optical system ZLI according to the 10th embodiment satisfies the following conditional expression (JJ2).

0.010<|fF/fXR|<10.000  (JJ2)

where, fF denotes a focal length of the focusing lens group GF, and
fXR denotes a focal length of the lens group closest to the image surface in the front-side lens group GX.
The conditional expression (JJ2) is for setting an appropriate value of the focal length of the focusing lens group GF with respect to the focal length of the lens group facing the object side of the focusing lens group GF. An appropriate movement amount of the focusing lens group GF can be obtained with the short distance performance maintained, when the conditional expression (JJ2) is satisfied.
A value higher than the upper limit value of the conditional expression (JJ2) results in a long focal length fF, that is, a large movement amount of the focusing lens group GF upon focusing, leading to large spherical aberration and curvature of field aberration. The large movement amount of the focusing lens group GF leads to a large entire length. Furthermore, the value results in a short focal length of the lens group facing the object side of the focusing lens group GF, and thus leads to the focusing lens group involving a large spherical aberration.
To guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ2) is preferably set to be 8.000. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ2) is preferably set to be 6.000.
A value lower than a lower limit value of the conditional expression (JJ2) results in a short focal length of the focusing lens group GF, and thus leads to the focusing lens group GF involving large spherical aberration and curvature of field aberration.
To guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ2) is preferably set to be 0.300. To more effectively guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ2) is preferably set to be 0.650.
Preferably, the zoom optical system ZLI according to the 10th embodiment satisfies the following conditional expression (JJ3).

0.000<βFw<0.800  (JJ3)

where, βFw denotes lateral magnification of the focusing lens group GF in the wide angle end state.
The conditional expression (JJ3) is for setting an appropriate range of the magnification of the focusing lens group GF in the wide angle end state. When the conditional expression (JJ3) is satisfied, the magnification related to the focusing lens group GF is appropriately set even when a sensor size is large, and thus the variation of aberration can be successfully reduced.
A value higher than an upper limit value of the conditional expression (JJ3) results in a successful reduction of the movement amount of the focusing lens group GF but also results in failure to successfully correct variation of the spherical aberration upon focusing on a short distant object.
To guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ3) is preferably set to be 0.600. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ3) is preferably set to be 0.400. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ3) is preferably set to be 0.360. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ3) is preferably set to be 0.350.
A value lower than the lower limit value of the conditional expression (JJ3) leads to a large movement amount of the focusing lens group GF, and thus results in a large optical system, and failure to successfully correct variation of the spherical aberration and the curvature of field aberration upon focusing.
To guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ3) is preferably set to be 0.020. To more effectively guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ3) is preferably set to be 0.040. To more effectively guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ3) is preferably set to be 0.060. To more effectively guarantee the effects of the 10th embodiment, the lower limit value of the conditional expression (JJ3) is preferably set to be 0.080.
Preferably, in the zoom optical system ZLI according to the 10th embodiment, the focusing lens group GF includes at least one negative lens that satisfies the following conditional expression (JJ4).

υdn<40.000  (JJ4)

where, υdn denotes Abbe number on the d-line of the negative lens.
The conditional expression (JJ4) is for setting an appropriate value of the Abbe number of the negative lens in the focusing lens group GF. Variation of a chromatic aberration upon focusing can be successfully reduced when the conditional expression (JJ4) is satisfied.
A value higher than an upper limit value of the conditional expression (JJ4) results in a failure to successfully correct the color aberration at the focusing lens group GF.
To guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ4) is preferably set to be 38.000. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ4) is preferably set to be 36.000. To more effectively guarantee the effects of the 10th embodiment, the upper limit value of the conditional expression (JJ4) is preferably set to be 34.000.
As described above, the 10th embodiment can achieve the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 1 including the above-described zoom optical system ZLI will be described with reference to FIG. 19. This camera 1 is the same as that in the 1st embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLI according to the 10th embodiment, installed in the camera 1 as the imaging lens 2, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device with a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 1.
The 10th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 1 can be obtained with the above-described zoom optical system ZLI installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLI (ZL1) will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power and disposed closest to an object, the front-side lens group GX composed of one or more lens groups and disposed more on the image surface side than the first lens group G1, the intermediate lens group GM disposed more on the image surface side than the front-side lens group GX, and the rear-side lens group GR composed of one or more lens groups and disposed more on the image surface side than the intermediate lens group GM are arranged in a barrel (step ST1010). The lenses are arranged in such a manner that the front-side lens group GX includes a lens group with negative refractive power (step ST1020). The lenses are arranged in such a manner that at least part of the intermediate lens group GM serves as the focusing lens group GF, and that the focusing lens group GF has positive refractive power and moves in the optical axis direction upon focusing (step ST1030). The lenses are arranged in such a manner that the vibration-proof lens group VR is disposed between the focusing lens group GF and a lens closest to the image surface, and the vibration-proof lens group VR can move with a displacement component in the direction orthogonal to the optical axis (step ST1040). The lenses are arranged in such a manner that upon zooming, the first lens group G1 is moved with respect to an image surface, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed (step ST1050). The lenses are arranged to satisfy at least the conditional expression (JJ1) in the conditional expressions described above (step ST1060).
In one example of the lens arrangement according to the 10th embodiment, as illustrated in FIG. 1, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image surface side, the negative meniscus lens L22 having a concave surface facing the object side, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the biconvex lens L31, the aperture stop S, the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33, the biconvex lens L34, and the cemented lens including the biconvex lens L35 and the biconcave lens L36, the fourth lens group G4 including the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side, and the fifth lens group G5 including the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52, the biconvex lens L53, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLI is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 10th embodiment, the zoom optical system ZLI featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
Examples According to 1st to 10th Embodiments
Examples according to the 1st to the 10th embodiments are described with reference to the drawings. Table 1 to Table 14 described below are specification tables of Examples 1 to 14.
The 1st embodiment corresponds to Examples 1 to 7, Example 12, and the like.
The 2nd embodiment corresponds to Examples 1, 2, 4, 8, 10, 11, and 13, and the like.
The 3rd embodiment corresponds to Examples 2 to 6, Examples 9 to 12, and the like.
The 4th embodiment corresponds to Examples 1 to 3, Examples 6 to 11, Example 13, and the like.
The 5th embodiment corresponds to Examples 1 to 13, and the like.
The 6th embodiment corresponds to Examples 2 to 6, Examples 9 to 12, and the like.
The 7th embodiment corresponds to Examples 1 to 6, Examples 13 and 14, and the like.
The 8th embodiment corresponds to Examples 1, 2, 4, and 13, and the like.
The 9th embodiment corresponds to Examples 7 to 12, and the like.
The 10th embodiment corresponds to Examples 1 to 6, Examples 13 and 14, and the like.
FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG. 7, FIG. 8 (FIG. 9), FIG. 10 (FIG. 11), FIG. 12 (FIG. 13), FIG. 14 (FIG. 15), FIG. 16, FIG. 17, FIG. 18 are cross-sectional views illustrating configurations and refractive power distributions of the zoom optical systems ZLI (ZL1 to ZL14) according to Examples. The movement directions of the lens groups along the optical axis upon zooming from the wide angle end state(W) to the telephoto end state(T) are indicated by arrows on the lower side of the cross-sectional views corresponding to the zoom optical systems ZL1 to ZL14. A movement direction of the focusing lens group GF upon focusing from infinity to a short-distant object and movement of the vibration-proof lens group VR upon image blur correction are indicated by arrows on the upper side of the cross-sectional views corresponding to the zoom optical systems ZL1 to ZL14.
Reference signs in FIG. 1 corresponding to Example are independently provided for each Example, to avoid complication of description due to increase in the number of digits of the reference signs. Thus, reference signs that are the same as those in a drawing corresponding to another Example do not necessarily indicate a configuration that is the same as that in the other Example.
Table 1 to Table 14 described below are specification tables of Examples 1 to 14.
In Examples, d-line (wavelength 587.562 nm) and g-line (wavelength 435.835 nm) are selected as calculation targets of the aberration characteristics.
In [Lens specifications] in the tables, a surface number represents an order of an optical surface from the object side in a traveling direction of a light beam, R represents a radius of curvature of each optical surface, D represents a distance between each optical surface and the next optical surface (or the image surface) on the optical axis, nd represents a refractive index of a material of an optical member with respect to the d-line, and υd represents Abbe number of the material of the optical member based on the d-line. Furthermore, obj surface represents an object surface, (Di) represents a distance between an ith surface and an (i+1)th surface; “∞” of a radius of curvature represents a plane or surface of an aperture, (stop S) represents the aperture stop S, and img surface represents the image surface I. An aspherical optical surface has a * mark in the field of surface number and has a paraxial radius of curvature in the field of radius of curvature R.
In the table, [Aspherical data] has the following formula (a) indicating the shape of an aspherical surface in [Lens specifications]. In the formula, X(y) represents a distance between the tangent plane at the vertex of the aspherical surface and a position on the aspherical surface at a height y along the optical axis direction, R represents a radius of curvature (paraxial radius of curvature) of a reference spherical surface, K represents a conical coefficient, and Ai represents ith aspherical coefficient. In the formula, “E-n” represents “×10−n”. For example, 1.234E−05=1.234×10−5. A secondary aspherical coefficient A2 is 0, and is omitted.

X(y)=(y2/R)/{1+(1−κ×y2/R2)1/2}+A4×y4+A6×y6+A8×y8+A10×y10+A12×y12  (a)

In [Various data] in Tables, f represents a focal length of the whole zoom lens; FNo represents an F number, w represents a half angle of view (unit: °), Y represents the maximum image height, BF represents a distance between the lens last surface and the image surface I on the optical axis upon focusing on infinity, BF(air) represents a distance between the distance between the lens last surface and the image surface I on the optical axis upon focusing on infinity described with an air equivalent length, TL represents a value obtained by adding BF to a distance between the lens forefront surface and the lens last surface on the optical axis upon focusing on infinity, and TL(air) represents a value obtained by adding BF(air) to the distance between the lens forefront surface and the lens last surface on the optical axis upon focusing on infinity.
In [Variable distance data] in Tables, values of the focal length f of the whole system, the maximum imaging magnification β, and variable distance values Di in states such as the wide angle end state, the intermediate focal length, and the telephoto end state with respect to an infinity object point and a short-distant object point are described. In [Variable distance data], DO represents the distance between the object and the vertex of the lens surface closest to the object in the zoom optical system ZLI on the optical axis, and Di represents the variable distance between the ith surface and the (i+1)th surface.
In [Lens group data] in Tables, the starting surface and the focal length of each of the lens groups are described.
In [Conditional expression corresponding value] in Tables, values corresponding to the conditional expression are described.
The focal length f, the radius of curvature R, and the distance to the next lens surface D described below as the specification values, which are generally described with “mm” unless otherwise noted should not be construed in a limiting sense because the optical system proportionally expanded or reduced can have a similar or the same optical performance. The unit is not limited to “mm”, and other appropriate units may be used.
The description on Tables described above commonly applies to all Examples, and thus will not be described below.
Example 1
Example 1 is described with reference to FIG. 1 and Table 1. A zoom optical system ZLI (ZL1) according to Example 1 includes, as illustrated in FIG. 1, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 having negative refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 corresponds to the rear-side lens group GR. The cemented lens including the lenses L51 and L52 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes: the negative meniscus lens L21 having a concave surface facing the image surface side; the negative meniscus lens L22 having a concave surface facing the object side; the biconvex lens L23; and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side.
The negative meniscus lens L21 is a composite type aspherical lens with a resin layer, formed on a glass surface on the object side, formed to have an aspherical shape. The negative meniscus lens L24 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The third lens group G3 includes: the biconvex lens L31; the aperture stop S; the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33; the biconvex lens L34; and the cemented lens including the biconvex lens L35 and the biconcave lens L36 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side.
The fifth lens group G5 includes: the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52; the biconvex lens L53; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
Upon zooming from the wide angle end state to the telephoto end state, the distance between the lens groups changes with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3 to the fifth lens group G5 each moved toward the object side.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the cemented lens including the lenses L51 and L52 forming the fifth lens group G5, and serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
More specifically, for correcting roll blur of an angle θ, the vibration-proof lens group VR (moved lens group) for image blur correction may be moved in a direction orthogonal to the optical axis by (f×tan θ)/K, where f represents the focal length of the entire system and K represents a vibration proof coefficient (a rate of an image movement amount of the imaging surface to the movement amount of the moved lens group in the image blur correction) (the same applies to Examples described hereafter).
In Example 1, in the wide angle end state, the vibration proof coefficient is −0.94 and the focal length is 24.70 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.30 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.18 and the focal length is 49.50 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.47° is −0.34 (mm). In the telephoto end state, the vibration proof coefficient is −1.42 and the focal length is 82.45 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.36° is −0.37 (mm).
In Table 1 below, specification values in Example 1 are listed. Surface numbers 1 to 35 in Table 1 respectively correspond to the optical surfaces m1 to m35 in FIG. 1.







TABLE 1







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
381.35819
2.000
1.92286
20.9


2
118.42462
5.839
1.59319
67.9


3
−500.00000
0.100
1.00000


4
51.34579
5.946
1.75500
52.3


5
140.29515
(D5) 
1.00000


*6
153.53752
0.100
1.56093
36.6


7
100.88513
1.250
1.83481
42.7


8
15.12764
9.324
1.00000


9
−29.69865
1.000
1.80400
46.6


10
−197.12774
0.100
1.00000


11
127.34178
5.891
1.80809
22.7


12
−24.40815
0.725
1.00000


13
−21.03104
1.200
1.88202
37.2


*14
−47.84526
(D14)
1.00000


*15
104.68107
2.068
1.72903
54.0


16
−238.15028
1.000
1.00000


17
(stop S)
1.000
1.00000


18
33.71098
1.000
1.71999
50.3


19
21.08311
5.564
1.49782
82.6


20
−287.32080
0.100
1.00000


21
44.42896
4.104
1.48749
70.3


22
−74.98744
0.100
1.00000


23
93.37205
4.530
1.95000
29.4


24
−30.50479
1.000
1.79504
28.7


25
21.31099
(D25)
1.00000


26
42.79038
5.914
1.58313
59.4


27
−19.56656
1.000
1.79504
28.7


28
−36.93977
(D28)
1.00000


29
−157.49872
3.569
1.84666
23.8


30
−23.26034
1.000
1.76802
49.2


*31
33.47331
3.639
1.00000


32
32.59617
9.754
1.49782
82.6


33
−21.57307
1.578
1.00000


34
−20.70024
1.350
1.90366
31.3


35
−59.06966
(D35)
1.00000


Img surface
∞












[Aspherical data]







6th surface



κ = 1.00000e+00



A4 = 1.00626e−05



A6 = −2.34691e−08



A8 = 4.64513e−11



A10 = −8.81427e−14



A12 = 1.22100e−16



14th surface



κ = 1.00000e+00



A4 = −5.05678e−06



A6 = −8.17158e−09



A8 = −3.38974e−11



A10 = 0.00000e+00



A12 = 0.00000e+00



15th surface



κ = 1.00000e+00



A4 = −8.97022e−06



A6 = −1.67376e−09



A8 = −7.29023e−12



A10 = 0.00000e+00



A12 = 0.00000e+00



31st surface



κ = 1.00000e+00



A4 = 1.12150e−06



A6 = −1.21533e−08



A8 = 6.82916e−11



A10 = 0.00000e+00



A12 = 0.00000e+00











[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.70
49.50
82.45



FNo
2.88
3.61
4.12



ω
41.2
23.5
14.4



Y
19.55
21.63
21.63



TL
143.097
153.553
175.036



BF
25.126
34.230
43.854



BF(air)
25.126
34.230
43.854











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.70
49.50
82.45
—
—
—


β
—
—
—
−0.1348
−0.1762
−0.2540


D0
∞
∞
∞
156.90
246.45
274.96


D5
1.500
14.321
30.131
1.500
14.321
30.131


D14
23.482
6.878
1.500
23.482
6.878
1.500


D25
9.245
7.876
9.245
7.646
4.490
2.131


D28
2.000
8.505
8.562
3.599
11.891
15.675


D35
25.126
34.230
43.854
25.126
34.230
43.854










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
95.95



Second lens group
6
−18.31



Third lens group
15
41.62



Fourth lens group
26
42.13



Fifth lens group
29
−75.33













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 0.559



Conditional expression(JA2) (−fXn)/fXR = 0.440



Conditional expression(JA3) fF/fW = 1.706



Conditional expression(JA4) Wω = 41.209



Conditional expression(JA5) fF/fXR = 1.012



Conditional expression(JA6) DXRFT/fF = 0.219



Conditional expression(JA7) Tω = 14.424



Conditional expression(JA8) DGXR/fXR = 0.492



Conditional expression(JB1) (DMRT − DMRW)/fF = 0.156



Conditional expression(JB2) Wω = 41.209



Conditional expression(JB3) Tω = 14.424



Conditional expression(JB4) fF/fRF = −0.559



Conditional expression(JB5) fF/fXR = 1.012



Conditional expression(JB6) DGXR/fXR = 0.492



Conditional expression(JD1) fV/fRF = 0.527



Conditional expression(JD2) DVW/fV = −0.092



Conditional expression(JD3) Wω = 41.209



Conditional expression(JD4) fF/fXR = 1.012



Conditional expression(JD5) (−fXn)/fXR = 0.440



Conditional expression(JD6) DGXR/fXR = 0.492



Conditional expression(JE1) DVW/fV = −0.092



Conditional expression(JE2) Wω = 41.209



Conditional expression(JE3) fF/fW = 1.706



Conditional expression(JE4) fV/fRF = 0.527



Conditional expression(JE5) fF/fXR = 1.012



Conditional expression(JE6) DGXR/fXR = 0.492



Conditional expression(JE7) DXnW/ZD1 = 0.735



Conditional expression(JG1) βFt = −0.077



Conditional expression(JG2) (rB + rA)/(rB − rA) = 2.984



Conditional expression(JG3) βFw = 0.252



Conditional expression(JH1) (rB + rA)/(rB − rA) = 2.984



Conditional expression(JH2) (rC + rB)/(rC − rB) = −0.073



Conditional expression(JH3) |fF/fXR| = 1.012



Conditional expression(JH4) βFw = 0.252



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 2.984



Conditional expression(JJ2) |fF/fXR| = 1.012



Conditional expression(JJ3) βFw = 0.252



Conditional expression(JJ4) νdn = 28.690










It can be seen in Table 1 that the zoom optical system ZL1 according to Example 1 satisfies the conditional expressions (JA1) to (JA8), (JB1) to (JB6), (JD1) to (JD6), (JE1) to (JE7), (JG1) to (JG3), (JH1) to (JH4), and (JJ1) to (JJ4).
Example 2
Example 2 is described with reference to FIG. 2 and Table 2. A zoom optical system ZLI (ZL2) according to Example 2 includes, as illustrated in FIG. 2, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having negative refractive power, and the sixth lens group G6 having positive refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The cemented lens including the lenses L51 and L52 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side.
The negative meniscus lens L21 is a composite type aspherical lens with a resin layer, formed on a glass surface on the object side, formed to have an aspherical shape. The negative meniscus lens L24 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The third lens group G3 includes: the biconvex lens L31; the aperture stop S; the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33; the biconvex lens L34; and the cemented lens including the biconvex lens L35 and the biconcave lens L36 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side.
The fifth lens group G5 includes: the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52; the biconvex lens L53; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The sixth lens group G6 includes the plano-convex lens L61 having a convex surface facing the object side.
Upon zooming from the wide angle end state to the telephoto end state, the distance between the lens groups changes with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, the third lens group G3 to the fifth lens group G5 each moved toward the object side, and the sixth lens group G6 moved toward the image surface side and stopped.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the cemented lens including the lenses L51 and L52 forming the fifth lens group G5, and serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In Example 2, in the wide angle end state, the vibration proof coefficient is −0.90 and the focal length is 24.70 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.32 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.13 and the focal length is 49.50 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.47° is −0.36 (mm). In the telephoto end state, the vibration proof coefficient is −1.39 and the focal length is 82.45 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.36° is −0.38 (mm).
In Table 2 below, specification values in Example 2 are listed. Surface numbers 1 to 37 in Table 2 respectively correspond to the optical surfaces m1 to m37 in FIG. 2.







TABLE 2







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
359.61837
2.000
1.92286
20.9


2
116.11567
5.903
1.59319
67.9


3
−500.00000
0.100
1.00000


4
52.83898
5.793
1.75500
52.3


5
147.40256
(D5) 
1.00000


*6
115.98790
0.100
1.56093
36.6


7
104.86281
1.250
1.83481
42.7


8
15.37855
9.261
1.00000


9
−34.42374
1.000
1.80400
46.6


10
1416.33070
0.793
1.00000


11
227.12896
5.779
1.80809
22.7


12
−24.67083
0.853
1.00000


13
−21.21084
1.200
1.88202
37.2


*14
−41.40267
(D14)
1.00000


*15
85.72894
2.079
1.72903
54.0


16
−479.69633
1.000
1.00000


17
(stop S)
1.000
1.00000


18
32.99718
1.000
1.71999
50.3


19
20.35793
5.787
1.49782
82.6


20
−240.67823
0.100
1.00000


21
38.71137
4.194
1.48749
70.3


22
−88.89400
0.100
1.00000


23
79.80151
4.537
1.95000
29.4


24
−31.24970
1.000
1.79504
28.7


25
19.62299
(D25)
1.00000


26
42.91576
5.430
1.58313
59.4


27
−21.06499
1.000
1.79504
28.7


28
−40.55627
(D28)
1.00000


29
−146.83351
3.433
1.84666
23.8


30
−24.26623
1.000
1.76801
49.2


*31
34.22177
4.214
1.00000


32
32.96615
10.097 
1.49782
82.6


33
−22.52074
2.026
1.00000


34
−21.40929
1.350
1.90366
31.3


35
−71.06117
(D35)
1.00000


36
264.25001
2.645
1.75500
52.3


37
0.00000
(D37)
1.00000


Img surface
∞












[Aspherical data]







6th surface



κ = 1.00000e+00



A4 = 4.18792e−06



A6 = −1.42449e−08



A8 = 2.61317e−11



A10 = −5.51120e−14



A12 = 7.44400e−17



14th surface



κ = 1.00000e+00



A4 = −6.91770e−06



A6 = −9.53529e−09



A8 = −3.52582e−11



A10 = 000000e+00



A12 = 000000e+00



15th surface



κ = 1.00000e+00



A4 = −8.57335e−06



A6 = −1.84259e−09



A8 = −2.99082e−12



A10 = 000000e+00



A12 = 000000e+00



31st surface



κ = 1.00000e+00



A4 = 9.53637e−07



A6 = −1.23037e−08



A8 = 6.38181e−11



A10 = 000000e+00



A12 = 000000e+00











[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.70
49.50
82.45



FNo
2.88
3.66
4.18



ω
41.2
23.5
14.4



Y
19.53
21.63
21.63



TL
143.097
153.886
175.269



BF
19.550
18.000
18.000



BF(air)
19.550
18.000
18.000











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.70
49.50
82.45
—
—
—


β
—
—
—
−0.1347
−0.1757
−0.2508


D0
∞
∞
∞
156.90
246.11
274.73


D5
1.500
14.377
30.069
1.500
14.377
30.069


D14
23.496
6.830
1.500
23.496
6.830
1.500


D25
9.027
8.025
9.027
7.291
4.564
2.193


D28
2.000
8.179
7.861
3.736
11.640
14.695


D35
1.500
12.451
22.788
1.500
12.451
22.788


D37
19.550
18.000
18.000
19.550
18.000
18.000










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
96.84



Second lens group
6
−19.18



Third lens group
15
40.71



Fourth lens group
26
44.16



Fifth lens group
29
−63.84



Sixth lens group
36
350.00













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 0.692



Conditional expression(JA2) (−fXn)/fXR = 0.471



Conditional expression(JA3) fF/fW = 1.788



Conditional expression(JA4) Wω = 41.170



Conditional expression(JA5) fF/fXR = 1.085



Conditional expression(JA6) DXRFT/fF = 0.204



Conditional expression(JA7) Tω = 14.405



Conditional expression(JA8) DGXR/fXR = 0.511



Conditional expression(JB1) (DMRT − DMRW)/fF = 0.133



Conditional expression(JB2) Wω = 41.170



Conditional expression(JB3) Tω = 14.405



Conditional expression(JB4) fF/fRF = −0.692



Conditional expression(JB5) fF/fXR = 1.085



Conditional expression(JB6) DGXR/fXR = 0.511



Conditional expression(JC1) |fF/fRF| = 0.692



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.133



Conditional expression(JC3) Wω = 41.170



Conditional expression(JC4) Tω = 14.405



Conditional expression(JC5) fRF/fRF2 = −0.182



Conditional expression(JC6) DGXR/fXR = 0.511



Conditional expression(JD1) fV/fRF = 0.621



Conditional expression(JD2) DVW/fV = −0.106



Conditional expression(JD3) Wω = 41.170



Conditional expression(JD4) fF/fXR = 1.085



Conditional expression(JD5) (−fXn)/fXR = 0.471



Conditional expression(JD6) DGXR/fXR = 0.511



Conditional expression(JE1) DVW/fV = −0.106



Conditional expression(JE2) Wω = 41.170



Conditional expression(JE3) fF/fW = 1.788



Conditional expression(JE4) fV/fRF = 0.621



Conditional expression(JE5) fF/fXR = 1.085



Conditional expression(JE6) DGXR/fXR = 0.511



Conditional expression(JE7) DXnW/ZD1 = 0.730



Conditional expression(JF1) fF/fV = −1.113



Conditional expression(JF2) fV/fRF = 0.621



Conditional expression(JF3) DVW/fV = −0.106



Conditional expression(JF4) Wω = 41.170



Conditional expression(JF5) fF/fXR = 1.085



Conditional expression(JF6) DGXR/fXR = 0.511



Conditional expression(JF7) TLW/ZD1 = 4.448



Conditional expression(JG1) βFt = 0.011



Conditional expression(JG2) (rB + rA)/(rB − rA) = 2.685



Conditional expression(JG3) βFw = 0.301



Conditional expression(JH1) (rB + rA)/(rB − rA) = 2.685



Conditional expression(JH2) (rC + rB)/(rC − rB) = −0.028



Conditional expression(JH3) |fF/fXR| = 1.085



Conditional expression(JH4) βFw = 0.301



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 2.685



Conditional expression(JJ2) |fF/fXR| = 1.085



Conditional expression(JJ3) βFw = 0.301



Conditional expression(JJ4) νdn = 28.690










It can be seen in Table 2 that the zoom optical system ZL2 according to Example 2 satisfies the conditional expressions (JA1) to (JA8), (JB1) to (JB6), (JC1) to (JC6), (JD1) to (JD6), (JE1) to (JE7), (JF1) to (JF7), (JG1) to (JG3), (JH1) to (JH4), and (JJ1) to (JJ4).
Example 3
Example 3 is described with reference to FIG. 3 and Table 3. A zoom optical system ZLI (ZL3) according to Example 3 includes, as illustrated in FIG. 3, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having negative refractive power, and the sixth lens group G6 having positive refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The cemented lens including the lenses L51 and L52 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side.
The negative meniscus lens L21 is a composite type aspherical lens with a resin layer, formed on a glass surface on the object side, formed to have an aspherical shape. The negative meniscus lens L24 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The third lens group G3 includes: the biconvex lens L31; the aperture stop S; the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33; the biconvex lens L34; and the cemented lens including the biconvex lens L35 and the biconcave lens L36 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side.
The fifth lens group G5 includes: the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52; the biconvex lens L53; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The sixth lens group G6 includes the plano-convex lens L61 having a convex surface facing the object side.
Upon zooming from the wide angle end state to the telephoto end state, the distance between the lens groups changes with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, the third lens group G3 to the fifth lens group G5 each moved toward the object side, and the sixth lens group G6 fixed.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the cemented lens including the lenses L51 and L52 forming the fifth lens group G5, and serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In Example 3, in the wide angle end state, the vibration proof coefficient is −0.89 and the focal length is 24.70 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.32 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.12 and the focal length is 49.50 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.47° is −0.36 (mm). In the telephoto end state, the vibration proof coefficient is −1.36 and the focal length is 82.45 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.36° is −0.38 (mm).
In Table 3 below, specification values in Example 3 are listed. Surface numbers 1 to 37 in Table 3 respectively correspond to the optical surfaces m1 to m37 in FIG. 3.







TABLE 3







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
401.00863
2.000
1.92286
20.9


2
121.16792
5.742
1.59319
67.9


3
−500.00000
0.100
1.00000


4
52.80844
5.796
1.75500
52.3


5
147.40686
(D5) 
1.00000


*6
108.54719
0.100
1.56093
36.6


7
99.55361
1.250
1.83481
42.7


8
15.35689
9.477
1.00000


9
−34.05998
1.000
1.80400
46.6


10
2673.65980
0.729
1.00000


11
251.58062
5.749
1.80809
22.7


12
−24.57937
0.829
1.00000


13
−21.23925
1.200
1.88202
37.2


*14
−41.22866
(D14)
1.00000


*15
86.90278
2.077
1.72903
54.0


16
−447.48345
1.000
1.00000


17
(stop S)
1.000
1.00000


18
33.03101
1.012
1.71999
50.3


19
19.99010
5.930
1.49782
82.6


20
−183.22190
0.100
1.00000


21
37.75493
4.200
1.48749
70.3


22
−92.50584
0.100
1.00000


23
79.05844
4.581
1.95000
29.4


24
−30.34409
1.000
1.79504
28.7


25
19.34777
(D25)
1.00000


26
42.98351
5.284
1.58313
59.4


27
−22.08681
1.000
1.79504
28.7


28
−42.74259
(D28)
1.00000


29
−142.46452
3.388
1.84666
23.8


30
−24.56214
1.000
1.76801
49.2


*31
34.56633
4.383
1.00000


32
34.09549
10.068 
1.49782
82.6


33
−22.62444
2.036
1.00000


34
−21.66642
1.350
1.90366
31.3


35
−72.61079
(D35)
1.00000


36
211.40000
2.805
1.75500
52.3


37
0.00000
(D37)
1.00000


Img surface
∞












[Aspherical data]







6th surface



κ = 1.00000e+00



A4 = 3.98249e−06



A6 = −1.35472e−08



A8 = 2.33425e−11



A10 = −4.97934e−14



A12 = 6.80330e−17



14th surface



κ = 1.00000e+00



A4 = −6.91076e−06



A6 = −9.38363e−09



A8 = −3.61645e−11



A10 = 0.00000e+00



A12 = 0.00000e+00



15th surface



κ = 1.00000e+00



A4 = −8.54887e−06



A6 = −1.66295e−09



A8 = −2.55600e−12



A10 = 0.00000e+00



A12 = 0.00000e+00



31st surface



κ = 1.00000e+00



A4 = 9.30632e−07



A6 = −1.25999e−08



A8 = 6.47905e−11



A10 = 0.00000e+00



A12 = 0.00000e+00











[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.70
49.50
82.45



FNo
2.88
3.69
4.17



ω
41.2
23.5
14.4



Y
19.51
21.63
21.63



TL
143.096
153.330
175.621



BF
18.993
18.993
18.993



BF(air)
18.993
18.993
18.993











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.70
49.50
82.45
—
—
—


β
—
—
—
−0.1347
−0.1763
−0.2504


D0
∞
∞
∞
156.90
246.67
274.38


D5
1.500
13.708
30.328
1.500
13.708
30.328


D14
23.612
6.595
1.500
23.612
6.595
1.500


D25
9.104
7.953
9.104
7.333
4.455
2.224


D28
2.000
8.603
8.304
3.771
12.101
15.183


D35
1.602
11.192
21.108
1.602
11.192
21.108


D37
18.993
18.993
18.993
18.993
18.993
18.993










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
98.11



Second lens group
6
−19.28



Third lens group
15
40.04



Fourth lens group
26
45.21



Fifth lens group
29
−62.15



Sixth lens group
36
280.00













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 0.727



Conditional expression(JA2) (−fXn)/fXR = 0.482



Conditional expression(JA3) fF/fW = 1.830



Conditional expression(JA4) Wω = 41.170



Conditional expression(JA5) fF/fXR = 1.129



Conditional expression(JA6) DXRFT/fF = 0.201



Conditional expression(JA7) Tω = 14.423



Conditional expression(JA8) DGXR/fXR = 0.525



Conditional expression(JC1) |fF/fRF| = 0.727



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.139



Conditional expression(JC3) Wω = 41.170



Conditional expression(JC4) Tω = 14.423



Conditional expression(JC5) fRF/fRF2 = −0.222



Conditional expression(JC6) DGXR/fXR = 0.525



Conditional expression(JD1) fV/fRF = 0.639



Conditional expression(JD2) DVW/fV = −0.110



Conditional expression(JD3) Wω = 41.170



Conditional expression(JD4) fF/fXR = 1.129



Conditional expression(JD5) (−fXn)/fXR = 0.482



Conditional expression(JD6) DGXR/fXR = 0.525



Conditional expression(JE1) DVW/fV = −0.110



Conditional expression(JE2) Wω = 41.170



Conditional expression(JE3) fF/fW = 1.830



Conditional expression(JE4) fV/fRF = 0.639



Conditional expression(JE5) fF/fXR = 1.129



Conditional expression(JE6) DGXR/fXR = 0.525



Conditional expression(JE7) DXnW/ZD1 = 0.726



Conditional expression(JF1) fF/fV = −1.139



Conditional expression(JF2) fV/fRF = 0.639



Conditional expression(JF3) DVW/fV = −0.110



Conditional expression(JF4) Wω = 41.170



Conditional expression(JF5) fF/fXR = 1.129



Conditional expression(JF6) DGXR/fXR = 0.525



Conditional expression(JF7) TLW/ZD1= 4.399



Conditional expression(JG1) βFt = 0.035



Conditional expression(JG2) (rB + rA)/(rB − rA) = 2.637



Conditional expression(JG3) βFw = 0.323



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 2.637



Conditional expression(JJ2) |fF/fXR| = 1.129



Conditional expression(JJ3) βFw = 0.323



Conditional expression(JJ4) νdn = 28.690










It can be seen in Table 3 that the zoom optical system ZL3 according to Example 3 satisfies the conditional expressions (JA1) to (JA8), (JC1) to (JC6), (JD1) to (JD6), (JE1) to (JE7), (JF1) to (JF7), (JG1) to (JG3), and (JJ1) to (JJ4).
Example 4
Example 4 is described with reference to FIG. 4 and Table 4. A zoom optical system ZLI (ZL4) according to Example 4 includes, as illustrated in FIG. 4, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having negative refractive power, and the sixth lens group G6 having positive refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes: the negative meniscus lens L21 having a concave surface facing the image surface side; the negative meniscus lens L22 having a concave surface facing the object side; the biconvex lens L23; and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side.
The negative meniscus lens L21 is a composite type aspherical lens with a resin layer, formed on a glass surface on the object side, formed to have an aspherical shape. The negative meniscus lens L24 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The third lens group G3 includes: the biconvex lens L31; the aperture stop S; the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33; the biconvex lens L34; and the cemented lens including the biconvex lens L35 and the biconcave lens L36 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side.
The fifth lens group G5 includes the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52 arranged in order from the object side.
The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The sixth lens group G6 is composed a biconvex lens L61 and the negative meniscus lens L62 having a concave surface facing the object side that are arranged in order from the object side.
Upon zooming from the wide angle end state to the telephoto end state, the distance between the lens groups changes with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3 to the sixth lens group G6 each moved toward the object side.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In Example 4, in the wide angle end state, the vibration proof coefficient is −0.94 and the focal length is 24.70 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.30 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.17 and the focal length is 49.50 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.47° is −0.34 (mm). In the telephoto end state, the vibration proof coefficient is −1.42 and the focal length is 82.45 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.36° is −0.37 (mm).
In Table 4 below, specification values in Example 4 are listed. Surface numbers 1 to 35 in Table 4 respectively correspond to the optical surfaces m1 to m35 in FIG. 4.







TABLE 4







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
378.17737
2.000
1.92286
20.9


2
118.11934
5.844
1.59319
67.9


3
−500.00000
0.100
1.00000


4
51.63655
5.920
1.75500
52.3


5
141.87634
(D5) 
1.00000


*6
158.15149
0.100
1.56093
36.6


7
102.00883
1.250
1.83481
42.7


8
15.22160
9.303
1.00000


9
−29.63785
1.000
1.80400
46.6


10
−225.21525
0.104
1.00000


11
119.10029
5.891
1.80809
22.7


12
−24.72064
0.782
1.00000


13
−21.10048
1.200
1.88202
37.2


*14
−47.00882
(D14)
1.00000


*15
109.65633
2.066
1.72903
54.0


16
−215.77979
1.000
1.00000


17
(stop S)
1.000
1.00000


18
33.67783
1.000
1.71999
50.3


19
20.98173
5.562
1.49782
82.6


20
−304.24111
0.100
1.00000


21
43.99361
4.136
1.48749
70.3


22
−73.22133
0.100
1.00000


23
94.72252
4.517
1.95000
29.4


24
−30.47819
1.000
1.79504
28.7


25
21.31000
(D25)
1.00000


26
42.90428
5.891
1.58313
59.4


27
−19.57454
1.000
1.79504
28.7


28
−36.90143
(D28)
1.00000


29
−156.74405
3.568
1.84666
23.8


30
−23.21215
1.000
1.76801
49.2


*31
33.50218
(D31)
1.00000


32
32.35097
9.840
1.49782
82.6


33
−21.82936
1.696
1.00000


34
−20.79382
1.350
1.90366
31.3


35
−59.98623
(D35)
1.00000


Img surface
∞












[Aspherical data]







6th surface



κ = 1.00000e+00



A4 = 1.01851e−05



A6 = −2.38470e−08



A8 = 4.98807e−11



A10 = −9.80153e−14



A12 = 1.34160e−16



14th surface



κ = 1.00000e+00



A4 = −4.81580e−06



A6 = −8.49768e−09



A8 = −2.93682e−11



A10 = 0.00000e+00



A12 = 0.00000e+00



15th surface



κ = 1.00000e+00



A4 = −8.99460e−06



A6 = −2.39078e−09



A8 = −4.17876e−12



A10 = 0.00000e+00



A12 = 0.00000e+00



31st surface



κ = 1.00000e+00



A4 = 1.13063e−06



A6 = −1.26643e−08



A8 = 6.92538e−11



A10 = 0.00000e+00



A12 = 0.00000e+00











[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.70
49.50
82.45



FNo
2.88
3.61
4.12



ω
41.2
23.5
14.4



Y
19.55
21.63
21.63



TL
143.097
153.486
174.987



BF
24.715
33.738
43.584



BF(air)
24.715
33.738
43.584











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.70
49.50
82.45
—
—
—


β
—
—
—
−0.1348
−0.1761
−0.2538


D0
∞
∞
∞
156.90
246.51
275.01


D5
1.500
14.376
30.144
1.500
14.376
30.144


D14
23.482
6.861
1.500
23.482
6.861
1.500


D25
9.211
7.842
9.211
7.612
4.456
2.133


D28
2.000
8.508
8.464
3.599
11.894
15.542


D31
3.868
3.841
3.763
3.868
3.841
3.763


D35
24.715
33.738
43.584
24.715
33.738
43.584










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
96.10



Second lens group
6
−18.35



Third lens group
15
41.62



Fourth lens group
26
42.14



Fifth lens group
29
−39.73



Sixth lens group
32
82.66













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 1.061



Conditional expression(JA2) (−fXn)/fXR = 0.441



Conditional expression(JA3) fF/fW = 1.706



Conditional expression(JA4) Wω = 41.170



Conditional expression(JA5) fF/fXR = 1.013



Conditional expression(JA6) DXRFT/fF = 0.219



Conditional expression(JA7) Tω = 14.405



Conditional expression(JA8) DGXR/fXR = 0.492



Conditional expression(JB1) (DMRT − DMRW)/fF = 0.153



Conditional expression(JB2) Wω = 41.170



Conditional expression(JB3) Tω = 14.405



Conditional expression(JB4) fF/fRF = −1.061



Conditional expression(JB5) fF/fXR = 1.013



Conditional expression(JB6) DGXR/fXR = 0.492



Conditional expression(JC1) |fF/fRF| = 1.061



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.153



Conditional expression(JC3) Wω = 41.170



Conditional expression(JC4) Tω = 14.405



Conditional expression(JC5) fRF/fRF2 = −0.481



Conditional expression(JC6) DGXR/fXR = 0.492



Conditional expression(JE1) DVW/fV = −0.097



Conditional expression(JE2) Wω = 41.170



Conditional expression(JE3) fF/fW = 1.706



Conditional expression(JE4) fV/fRF = 1.000



Conditional expression(JE5) fF/fXR = 1.013



Conditional expression(JE6) DGXR/fXR = 0.492



Conditional expression(JE7) DXnW/ZD1 = 0.736



Conditional expression(JF1) fF/fV = −1.061



Conditional expression(JF2) fV/fRF = 1.000



Conditional expression(JF3) DVW/fV = −0.097



Conditional expression(JF4) Wω = 41.170



Conditional expression(JF5) fF/fXR = 1.013



Conditional expression(JF6) DGXR/fXR = 0.492



Conditional expression(JF7) TLW/ZD1 = 4.487



Conditional expression(JG1) βFt = −0.075



Conditional expression(JG2) (rB + rA)/(rB − rA) = 2.974



Conditional expression(JG3) βFw = 0.252



Conditional expression(JH1) (rB + rA)/(rB − rA) = 2.974



Conditional expression(JH2) (rC + rB)/(rC − rB) = −0.075



Conditional expression(JH3) |fF/fXR| = 1.013



Conditional expression(JH4) βFw = 0.252



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 2.974



Conditional expression(JJ2) |fF/fXR| = 1.013



Conditional expression(JJ3) βFw = 0.252



Conditional expression(JJ4) νdn = 28.690










It can be seen in Table 4 that the zoom optical system ZL4 according to Example 4 satisfies the conditional expressions (JA1) to (JA8), (JB1) to (JB6), (JC1) to (JC6), (JE1) to (JE7), (JF1) to (JF7), (JG1) to (JG3), (JH1) to (JH4), and (JJ1) to (JJ4).
Example 5
Example 5 is described with reference to FIG. 5 and Table 5. A zoom optical system ZLI (ZL5) according to Example 5 includes, as illustrated in FIG. 5, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having negative refractive power, and the sixth lens group G6 having positive refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes: the negative meniscus lens L21 having a concave surface facing the image surface side; the negative meniscus lens L22 having a concave surface facing the object side; the biconvex lens L23; and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side.
The negative meniscus lens L21 is a composite type aspherical lens with a resin layer, formed on a glass surface on the object side, formed to have an aspherical shape. The negative meniscus lens L24 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The third lens group G3 includes: the biconvex lens L31; the aperture stop S; the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33; the biconvex lens L34; and the cemented lens including the biconvex lens L35 and the biconcave lens L36 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side.
The fifth lens group G5 includes: the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52; the biconvex lens L53; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The sixth lens group G6 includes the biconvex lens L61.
Upon zooming from the wide angle end state to the telephoto end state, the distance between the lens groups changes with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, the third lens group G3 to the fifth lens group G5 each moved toward the object side, and the sixth lens group G6 fixed.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In Example 5, in the wide angle end state, the vibration proof coefficient is −0.62 and the focal length is 24.70 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.46 (mm). In the intermediate focal length state, the vibration proof coefficient is −0.81 and the focal length is 49.50 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.47° is −0.50 (mm). In the telephoto end state, the vibration proof coefficient is −0.95 and the focal length is 82.45 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.36° is −0.55 (mm).
In Table 5 below, specification values in Example 5 are listed. Surface numbers 1 to 37 in Table 5 respectively correspond to the optical surfaces m1 to m37 in FIG. 5.







TABLE 5







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
295.45596
2.000
1.92286
20.9


2
110.24643
5.870
1.59319
67.9


3
−762.56799
0.100
1.00000


4
52.19538
5.859
1.75500
52.3


5
144.16926
(D5) 
1.00000


*6
109.99857
0.100
1.56093
36.6


7
103.82935
1.250
1.83481
42.7


8
15.13651
9.424
1.00000


9
−34.78713
1.000
1.80400
46.6


10
−503.06886
0.819
1.00000


11
2775.06080
5.758
1.80809
22.7


12
−23.63444
0.718
1.00000


13
−20.84765
1.200
1.88202
37.2


*14
−39.84738
(D14)
1.00000


*15
82.51823
2.198
1.72903
54.0


16
−285.57791
1.186
1.00000


17
(stop S)
1.000
1.00000


18
32.15650
1.000
1.71999
50.3


19
19.37917
5.884
1.49782
82.6


20
−409.37679
0.249
1.00000


21
41.07452
4.188
1.48749
70.3


22
−76.88713
0.100
1.00000


23
74.66430
4.688
1.95000
29.4


24
−29.06368
1.000
1.79504
28.7


25
18.99382
(D25)
1.00000


26
41.64101
5.232
1.58313
59.4


27
−21.80056
1.000
1.79504
28.7


28
−43.03347
(D28)
1.00000


29
−68.65494
3.317
1.84666
23.8


30
−21.63496
1.000
1.76801
49.2


*31
37.94747
3.255
1.00000


32
35.65453
9.755
1.49782
82.6


33
−23.00928
3.310
1.00000


34
−21.30043
1.350
1.90366
31.3


35
−68.20008
(D35)
1.00000


36
90.55364
4.191
1.75500
52.3


37
−30469.89300
(D37)
1.00000


Img surface
∞












[Aspherical data]







6th surface



κ = 1.00000e+00



A4 = 3.67375e−06



A6 = −1.67560e−08



A8 = 4.54335e−11



A10 = −1.18164e−13



A12 = 1.47210e−16



14th surface



κ = 1.00000e+00



A4 = −7.51479e−06



A6 = −1.04712e−08



A8 = −4.76282e−11



A10 = 0.00000e+00



A12 = 0.00000e+00



15th surface



κ = 1.00000e+00



A4 = −8.62200e−06



A6 = −1.80573e−09



A8 = −3.76827e−12



A10 = 0.00000e+00



A12 = 0.00000e+00



31st surface



κ = 1.00000e+00



A4 = 2.00569e−07



A6 = −8.00922e−09



A8 = 2.97959e−11



A10 = 0.00000e+00



A12 = 0.00000e+00











[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.70
49.50
82.45



FNo
2.88
3.77
4.18



ω
41.2
23.6
14.4



Y
19.46
21.58
21.63



TL
143.097
153.446
174.658



BF
18.000
18.000
18.000



BF(air)
18.000
18.000
18.000











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.70
49.50
82.45
—
—
—


β
—
—
—
−0.1344
−0.1767
−0.2469


D0
∞
∞
∞
156.90
246.55
275.34


D5
1.500
12.508
29.852
1.500
12.508
29.852


D14
23.482
6.573
1.500
23.482
6.573
1.500


D25
8.585
7.859
8.614
6.830
4.586
2.213


D28
2.028
8.415
8.819
3.783
11.689
15.219


D35
1.500
12.088
19.873
1.500
12.088
19.873


D37
18.000
18.000
18.000
18.000
18.000
18.000










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
96.36



Second lens group
6
−19.49



Third lens group
15
39.23



Fourth lens group
26
44.83



Fifth lens group
29
−46.93



Sixth lens group
36
119.59













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 0.955



Conditional expression(JA2) (−fXn)/fXR = 0.497



Conditional expression(JA3) fF/fW = 1.815



Conditional expression(JA4) Wω = 41.170



Conditional expression(JA5) fF/fXR = 1.143



Conditional expression(JA6) DXRFT/fF = 0.192



Conditional expression(JA7) Tω = 14.423



Conditional expression(JA8) DGXR/fXR = 0.548



Conditional expression(JC1) |fF/fRF| = 0.955



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.151



Conditional expression(JC3) Wω = 41.170



Conditional expression(JC4) Tω = 14.423



Conditional expression(JC5) fRF/fRF2 = −0.392



Conditional expression(JC6) DGXR/fXR = 0.548



Conditional expression(JE1) DVW/fV = −0.032



Conditional expression(JE2) Wω = 41.170



Conditional expression(JE3) fF/fW = 1.815



Conditional expression(JE4) fV/fRF = 1.000



Conditional expression(JE5) fF/fXR = 1.143



Conditional expression(JE6) DGXR/fXR = 0.548



Conditional expression(JE7) DXnW/ZD1 = 0.744



Conditional expression(JF1) fF/fV = −0.955



Conditional expression(JF2) fV/fRF = 1.000



Conditional expression(JF3) DVW/fV = −0.032



Conditional expression(JF4) Wω = 41.170



Conditional expression(JF5) fF/fXR = 1.143



Conditional expression(JF6) DGXR/fXR = 0.548



Conditional expression(JF7) TLW/ZD1 = 4.534



Conditional expression(JG1) βFt = 0.084



Conditional expression(JG2) (rB + rA)/(rB − rA) = 2.677



Conditional expression(JG3) βFw = 0.344



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 2.677



Conditional expression(JJ2) |fF/fXR| = 1.143



Conditional expression(JJ3) βFw = 0.344



Conditional expression(JJ4) νdn = 28.690










It can be seen in Table 5 that the zoom optical system ZL5 according to Example 5 satisfies the conditional expressions (JA1) to (JA8), (JC1) to (JC6), (JE1) to (JE7), (JF1) to (JF7), (JG1) to (JG3), and (JJ1) to (JJ4).
Example 6
Example 6 is described with reference to FIG. 6 and Table 6. A zoom optical system ZLI (ZL6) according to Example 6 includes, as illustrated in FIG. 6, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having negative refractive power, and the sixth lens group G6 having negative refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes: the negative meniscus lens L21 having a concave surface facing the image surface side; the negative meniscus lens L22 having a concave surface facing the object side; the biconvex lens L23; and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side.
The negative meniscus lens L21 is a composite type aspherical lens with a resin layer, formed on a glass surface on the object side, formed to have an aspherical shape. The negative meniscus lens L24 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The third lens group G3 includes: the biconvex lens L31; the aperture stop S; the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33; the biconvex lens L34; and the cemented lens including the biconvex lens L35 and the biconcave lens L36 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side.
The fifth lens group G5 includes: the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52; the biconvex lens L53; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The sixth lens group G6 includes a negative meniscus lens L61 having a concave surface facing the object side.
Upon zooming from the wide angle end state to the telephoto end state, the distance between the lens groups changes with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, the third lens group G3 to the fifth lens group G5 each moved toward the object side, and the sixth lens group G6 fixed.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In Example 6, in the wide angle end state, the vibration proof coefficient is −0.48 and the focal length is 24.70 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.59 (mm). In the intermediate focal length state, the vibration proof coefficient is −0.59 and the focal length is 49.50 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.47° is −0.68 (mm). In the telephoto end state, the vibration proof coefficient is −0.74 and the focal length is 82.46 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.36° is −0.71 (mm).
In Table 6 below, specification values in Example 6 are listed. Surface numbers 1 to 37 in Table 6 respectively correspond to the optical surfaces m1 to m37 in FIG. 6.







TABLE 6







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
392.75985
2.000
1.92286
20.9


2
119.59613
5.794
1.59319
67.9


3
−500.00000
0.100
1.00000


4
51.57912
5.854
1.75500
52.3


5
137.74730
(D5) 
1.00000


*6
161.69102
0.100
1.56093
36.6


7
96.90163
1.250
1.83481
42.7


8
15.23869
9.338
1.00000


9
−29.78956
1.000
1.80400
46.6


10
−188.44242
0.100
1.00000


11
95.54244
5.972
1.80809
22.7


12
−25.31883
0.699
1.00000


13
−21.69584
1.200
1.88202
37.2


*14
−54.45730
(D14)
1.00000


*15
115.10942
2.078
1.72903
54.0


16
−187.67701
1.000
1.00000


17
(stop S)
1.000
1.00000


18
34.13749
1.000
1.71999
50.3


19
21.51053
5.519
1.49782
82.6


20
−269.16753
0.100
1.00000


21
46.87275
4.114
1.48749
70.3


22
−68.86740
0.100
1.00000


23
101.74251
4.500
1.95000
29.4


24
−30.45826
1.000
1.79504
28.7


25
21.82068
(D25)
1.00000


26
42.76309
5.976
1.58313
59.4


27
−18.88564
1.000
1.79504
28.7


28
−35.66684
(D28)
1.00000


29
−173.43687
3.567
1.84666
23.8


30
−23.10720
1.000
1.76801
49.2


*31
32.70838
3.851
1.00000


32
31.14900
9.731
1.49782
82.6


33
−21.98428
1.876
1.00000


34
−20.68510
1.350
1.90366
31.3


35
−63.60008
(D35)
1.00000


36
−198.28686
2.001
1.75500
52.3


37
−270.03296
(D37)
1.00000


Img surface
∞












[Aspherical data]







6th surface



κ = 1.00000e+00



A4 = 1.15342e−05



A6 = −2.68541e−08



A8 = 6.60621e−11



A10 = −1.47648e−13



A12 = 2.00960e−16



14th surface



κ = 1.00000e+00



A4 = −3.91709e−06



A6 = −7.48599e−09



A8 = −2.82710e−11



A10 = 0.00000e+00



A12 = 0.00000e+00



15th surface



κ = 1.00000e+00



A4 = −9.35866e−06



A6 = −2.05242e−09



A8 = −7.75454e−12



A10 = 0.00000e+00



A12 = 0.00000e+00



31st surface



κ = 1.00000e+00



A4 = 1.33757e−06



A6 = −1.37803e−08



A8 = 7.72183e−11



A10 = 0.00000e+00



A12 = 0.00000e+00











[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.70
49.50
82.46



FNo
2.88
3.58
4.12



ω
41.2
23.5
14.4



Y
19.60
21.63
21.63



TL
143.097
153.272
174.682



BF
18.314
18.314
18.314



BF(air)
18.314
18.314
18.314











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.70
49.50
82.46
—
—
—


β
—
—
—
−0.1348
−0.1751
−0.2532


D0
∞
∞
∞
156.90
246.73
275.32


D5
1.500
15.191
30.588
1.500
15.191
30.588


D14
23.482
6.907
1.500
23.482
6.907
1.500


D25
8.944
7.575
8.944
7.398
4.258
2.057


D28
2.000
8.848
8.851
3.546
12.165
15.738


D35
4.687
12.268
22.315
4.687
12.268
22.315


D37
18.314
18.314
18.314
18.314
18.314
18.314










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
97.91



Second lens group
6
−18.30



Third lens group
15
41.55



Fourth lens group
26
41.49



Fifth lens group
29
−71.27



Sixth lens group
36
−1000.48













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 0.582



Conditional expression(JA2) (−fXn)/fXR = 0.440



Conditional expression(JA3) fF/fW = 1.680



Conditional expression(JA4) Wω = 41.166



Conditional expression(JA5) fF/fXR = 0.999



Conditional expression(JA6) DXRFT/fF = 0.216



Conditional expression(JA7) Tω = 14.422



Conditional expression(JA8) DGXR/fXR = 0.491



Conditional expression(JC1) |fF/fRF| = 0.582



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.165



Conditional expression(JC3) Wω = 41.166



Conditional expression(JC4) Tω = 14.422



Conditional expression(JC5) fRF/fRF2 = 0.071



Conditional expression(JC6) DGXR/fXR = 0.491



Conditional expression(JD1) fV/fRF = 0.558



Conditional expression(JD2) DVW/fV = −0.097



Conditional expression(JD3) Wω = 41.166



Conditional expression(JD4) fF/fXR = 0.999



Conditional expression(JD5) (−fXn)/fXR = 0.440



Conditional expression(JD6) DGXR/fXR = 0.491



Conditional expression(JE1) DVW/fV = −0.097



Conditional expression(JE2) Wω = 41.166



Conditional expression(JE3) fF/fW = 1.680



Conditional expression(JE4) fV/fRF = 0.558



Conditional expression(JE5) fF/fXR = 0.999



Conditional expression(JE6) DGXR/fXR = 0.491



Conditional expression(JE7) DXnW/ZD1 = 0.743



Conditional expression(JF1) fF/fV = −1.044



Conditional expression(JF2) fV/fRF = 0.558



Conditional expression(JF3) DVW/fV = −0.097



Conditional expression(JF4) Wω = 41.166



Conditional expression(JF5) fF/fXR = 0.999



Conditional expression(JF6) DGXR/fXR = 0.491



Conditional expression(JF7) TLW/ZD1 = 4.531



Conditional expression(JG1) βFt = −0.086



Conditional expression(JG2) (rB + rA)/(rB − rA) = 3.084



Conditional expression(JG3) βFw = 0.247



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 3.084



Conditional expression(JJ2) |fF/fXR| = 0.999



Conditional expression(JJ3) βFw = 0.247



Conditional expression(JJ4) νdn = 28.690










It can be seen in Table 6 that the zoom optical system ZL6 according to Example 6 satisfies the conditional expressions (JA1) to (JA8), (JC1) to (JC6), (JD1) to (JD6), (JE1) to (JE7), (JF1) to (JF7), (JG1) to (JG3), and (JJ1) to (JJ4).
Example 7
Example 7 is described with reference to FIG. 7 and Table 7. A zoom optical system ZLI (ZL7) according to Example 7 includes, as illustrated in FIG. 7, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 having negative refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 corresponds to the rear-side lens group GR. The lens L51 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, and the positive meniscus lens L23 having a convex surface facing the object side that are arranged in order from the object side.
The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image surface side; and the cemented lens including the negative meniscus lens L34 having a concave surface facing the image surface side and the biconvex lens L35 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the positive meniscus lens L41 having a convex surface facing the object side.
The fifth lens group G5 includes the biconcave lens L51 and the plano-convex lens L52 having a convex surface facing the object side that are arranged in order from the object side.
The biconcave lens L51 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
Upon zooming from the wide angle end state to the telephoto end state, the distance between the lens groups changes with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3 to the fifth lens group G5 each moved toward the object side.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the lens L51 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
More specifically, for correcting roll blur of an angle θ, the vibration-proof lens group VR for image blur correction may be moved in a direction orthogonal to the optical axis by (f·tan θ)/K, where f represents the focal length of the entire system and K represents a vibration proof coefficient (a rate of an image movement amount of the imaging surface to the movement amount of the vibration-proof lens group VR in the image blur correction) (the same applies to Examples described hereafter).
In the wide angle end state, the vibration proof coefficient is −0.62 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.31 (mm). In the intermediate focal length state, the vibration proof coefficient is −0.99 and the focal length is 34.25 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is −0.28 (mm). In the telephoto end state, the vibration proof coefficient is −1.46 and the focal length is 58.20 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is −0.24 (mm).
In Table 7 below, specification values in Example 7 are listed. Surface numbers 1 to 24 in Table 7 respectively correspond to the optical surfaces m1 to m24 in FIG. 7.







TABLE 7







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
43.79676
1.500
1.94594
18.0


2
35.71919
8.259
1.72916
54.6


3
168.44179
(D3) 
1.00000


4
76.58634
1.000
1.83481
42.7


5
11.93768
8.172
1.00000


*6
−54.31728
1.000
1.72903
54.0


*7
44.95600
2.010
1.00000


8
38.50340
1.960
1.94594
18.0


9
296.58796
(D9) 
1.00000


*10
49.99513
2.935
1.72903
54.0


11
−182.58975
1.800
1.00000


12
(stop S)
1.500
1.00000


13
16.31284
5.400
1.49782
82.6


14
1195.94540
1.000
1.79504
28.7


15
24.50722
1.600
1.00000


*16
125.06202
1.163
1.61881
63.9


17
16.61859
5.607
1.49782
82.6


18
−16.44266
(D18)
1.00000


19
26.26030
1.950
1.49782
82.6


20
77.07450
(D20)
1.00000


21
−278.32369
1.000
1.72903
54.0


*22
23.32173
2.400
1.00000


23
28.41583
5.000
1.49782
82.6


24
0.00000
(D24)
1.00000


Img surface
∞










[Aspherical data]












Surface
κ
A4
A6
A8
A10





6
1.00000e+00
−4.02893e−05
1.52864e−07
2.23393e−11
−1.05980e−11 


7
1.00000e+00
−5.21860e−05
2.50219e−07
−1.77796e−09 
0.00000e+00


10
1.00000e+00
−8.87905e−06
−4.22167e−08 
4.77859e−11
1.70976e−13


16
1.00000e+00
−4.52195e−05
−6.85752e−08 
7.76036e−10
−8.98336e−12 


22
1.00000e+00
−3.30586e−06
5.77655e−09
−7.26907e−10 
1.01636e−11










[Various data]


Zoom ratio 3.53













Wide angle

Telephoto




end
Intermediate
end







f
16.48
34.25
58.20



FNo
2.85
3.89
3.99



ω
40.8
22.6
13.6



Y
12.66
14.19
14.25



TL
97.178
108.425
130.072



BF
13.112
24.600
39.181



BF(air)
13.112
24.600
39.181












[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.48
34.25
58.20
—
—
—


β
—
—
—
−0.1314
−0.1025
−0.2407


D0
∞
∞
∞
102.82
291.57
169.93


D3
0.800
13.732
25.000
0.800
13.732
25.000


D9
17.218
4.344
0.800
17.218
4.344
0.800


D18
3.824
3.000
8.436
1.470
0.510
1.217


D20
6.968
7.494
1.400
9.322
9.984
8.618


D24
13.112
24.600
39.181
13.112
24.600
39.181










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
85.49



Second lens group
4
−15.08



Third lens group
10
25.39



Fourth lens group
19
79.00



Fifth lens group
21
−66.87













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 1.181



Conditional expression(JA2) (−fXn)/fXR = 0.594



Conditional expression(JA3) fF/fW = 4.793



Conditional expression(JA4) Wω = 40.739



Conditional expression(JA5) fF/fXR = 3.112



Conditional expression(JA6) DXRFT/fF = 0.107



Conditional expression(JA7) Tω = 13.730



Conditional expression(JA8) DGXR/fXR = 0.827



Conditional expression(JD1) fV/fRF = 0.441



Conditional expression(JD2) DVW/fV = −0.081



Conditional expression(JD3) Wω = 40.739



Conditional expression(JD4) fF/fXR = 3.112



Conditional expression(JD5) (−fXn)/fXR = 0.594



Conditional expression(JD6) DGXR/fXR = 0.827



Conditional expression(JE1) DVW/fV = −0.081



Conditional expression(JE2) Wω = 40.739



Conditional expression(JE3) fF/fW = 4.793



Conditional expression(JE4) fV/fRF = 0.441



Conditional expression(JE5) fF/fXR = 3.112



Conditional expression(JE6) DGXR/fXR = 0.827



Conditional expression(JE7) DXnW/ZD1 = 0.523



Conditional expression(JI1) (rB + rA)/(rB − rA) = 0.230



Conditional expression(JI2) (rC + rB)/(rC − rB) = 2.034



Conditional expression(JI3) |fF/fXR| = 3.112



Conditional expression(JI4) νdp = 82.570










It can be seen in Table 7 that the zoom optical system ZL7 according to Example 7 satisfies the conditional expressions (JA1) to (JA8), (JD1) to (JD6), (JE1) to (JE7), and (JI1) to (JI4).
Example 8
Example 8 is described with reference to FIG. 8 and FIG. 9 and Table 8. A zoom optical system ZLI (ZL8) according to Example 8 includes, as illustrated in FIG. 8 (FIG. 9), the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The example illustrated in FIG. 8, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 corresponds to the rear-side lens group GR. The lens L51 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The example illustrated in FIG. 9, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 corresponds to the rear-side lens group GR. The lens L52 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, and the biconvex lens L23 that are arranged in order from the object side.
The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image surface side; and the cemented lens including the negative meniscus lens L34 having a concave surface facing the image surface side and the biconvex lens L35 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the positive meniscus lens L41 having a convex surface facing the object side.
The fifth lens group G5 includes a biconvex lens L51, the biconcave lens L52, the biconvex lens L53, and a biconvex lens L54 that are arranged in order from the object side.
The biconvex lens L51 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
Upon zooming from the wide angle end state to the telephoto end state, the distance between lens groups changes with the first lens group G1 to the fifth lens group G5 each moved toward the object side.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, as illustrated in FIG. 8, image blur correction (vibration isolation) on the image surface I is performed with the lens L51 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is 0.41 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is 0.47 (mm). In the intermediate focal length state, the vibration proof coefficient is 0.52 and the focal length is 34.52 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is 0.53 (mm). In the telephoto end state, the vibration proof coefficient is 0.59 and the focal length is 58.20 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is 0.61 (mm).
In this Example, when image blur occurs, as illustrated in FIG. 9, image blur correction (vibration isolation) on the image surface I may be performed with the lens L52 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is −1.29 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.15 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.74 and the focal length is 34.52 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is −0.16 (mm). In the telephoto end state, the vibration proof coefficient is −2.00 and the focal length is 58.20 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is −0.18 (mm).
In Table 8 below, specification values in Example 8 are listed. Surface numbers 1 to 28 in Table 8 respectively correspond to the optical surfaces m1 to m28 in FIG. 8 (FIG. 9).







TABLE 8







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
52.01929
1.500
1.94594
18.0


2
38.70649
6.705
1.80400
46.6


3
208.84711
(D3) 
1.00000


4
54.86747
1.000
1.80400
46.6


5
10.90252
9.493
1.00000


*6
−29.74452
1.000
1.72903
54.0


*7
85.46789
0.533
1.00000


8
62.70343
2.179
1.94594
18.0


9
−203.90514
(D9) 
1.00000


*10
52.30971
3.200
1.72903
54.0


11
−35.75411
1.800
1.00000


12
(stop S)
1.500
1.00000


13
47.59945
3.600
1.48749
70.3


14
54.00000
1.000
1.78472
25.6


15
25.22974
1.200
1.00000


*16
51.22589
1.186
1.72903
54.0


17
14.51681
6.030
1.49782
82.6


18
−19.84549
(D18)
1.00000


19
35.07568
1.811
1.49782
82.6


20
102.41627
(D20)
1.00000


*21
44.70967
2.605
1.55332
71.7


*22
−956.47865
1.500
1.00000


23
−53.34248
1.000
1.82080
42.7


*24
23.47902
4.995
1.00000


25
35.66383
3.530
1.59319
67.9


26
−477.30582
7.997
1.00000


27
69.46909
4.200
1.48749
70.3


28
−64.23027
(D28)
1.00000


Img surface
∞










[Aspherical data]












Surface
κ
A4
A6
A8
A10





6
1.00000e+00
−4.63019e−05
2.03870e−07
−6.42078e−10 
−2.02412e−11


7
1.00000e+00
−6.23690e−05
3.31714e−07
−2.89054e−09 
 0.00000e+00


10
1.00000e+00
−3.57796e−05
−1.16911e−08 
2.44047e−10
−3.29234e−12


16
1.00000e+00
 3.71472e−05
4.09580e−08
1.14439e−10
−6.41586e−14


21
1.00000e+00
−6.15920e−05
−4.51551e−07 
1.01307e−08
−4.84337e−11


22
1.00000e+00
−6.60557e−05
−7.74103e−07 
2.02734e−08
−1.26330e−10


24
1.00000e+00
−8.16006e−06
2.18577e−07
−6.23271e−09 
 4.73302e−11










[Various data]


Zoom ratio 3.53













Wide angle

Telephoto




end
Intermediate
end







f
16.48
34.52
58.20



FNo
2.88
4.00
4.60



ω
40.8
22.4
13.8



Y
12.51
13.77
13.93



TL
109.577
126.782
152.506



BF
13.038
26.069
33.683



BF(air)
13.038
26.069
33.683












[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.48
34.52
58.20
—
—
—


β
—
—
—
−0.1026
−0.0965
−0.2077


D0
∞
∞
∞
140.42
323.22
227.49


D3
1.000
13.111
25.000
1.000
13.111
25.000


D9
20.211
6.075
1.169
20.211
6.075
1.169


D18
3.000
4.000
12.524
0.838
0.578
1.421


D20
2.763
7.962
10.565
4.924
11.384
21.668


D28
13.038
26.069
33.683
13.038
26.069
33.683










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
91.06



Second lens group
4
−13.01



Third lens group
10
26.36



Fourth lens group
19
106.21



Fifth lens group
21
249.80













[Conditional expression corresponding value]







Conditional expression(JB1) (DMRT − DMRW)/fF = 0.073



Conditional expression(JB2) Wω = 40.847



Conditional expression(JB3) Tω = 13.758



Conditional expression(JB4) fF/fRF = 0.425



Conditional expression(JB5) fF/fXR = 4.029



Conditional expression(JB6) DGXR/fXR = 0.740



Conditional expression(JD1) fV/fRF = 0.309(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.079(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JD2) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.253(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JD3) Wω = 40.847



Conditional expression(JD4) fF/fXR = 4.029



Conditional expression(JD5) (−fXn)/fXR = 0.493



Conditional expression(JD6) DGXR/fXR = 0.740



Conditional expression(JE1) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



Conditional expression(JE2) Wω = 40.847



Conditional expression(JE3) fF/fW = 6.444



Conditional expression(JE4) fV/fRF = 0.309(in the event that



the vibration-proof lens group comprises lens L51)



Conditional expression(JE5) fF/fXR = 4.029



Conditional expression(JE6) DGXR/fXR = 0.740



Conditional expression(JE7) DXnW/ZD1 = 0.471



Conditional expression(JI1) (rB + rA)/(rB − rA) = 0.277



Conditional expression(JI2) (rC + rB)/(rC − rB) = 2.042



Conditional expression(JI3) |fF/fXR| = 4.029



Conditional expression(JI4) νdp = 82.570










It can be seen in Table 8 that the zoom optical system ZL8 according to Example 8 satisfies the conditional expressions (JB1) to (JB6), (JD1) to (JD6), (JE1) to (JE7), and (JI1) to (JI4).
Example 9
Example 9 is described with reference to FIG. 10 and FIG. 11 and Table 9. A zoom optical system ZLI (ZL9) according to Example 9 includes, as illustrated in FIG. 10 (FIG. 11), the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having positive refractive power, and the sixth lens group G6 having negative refractive power that are arranged in order from the object side.
The example illustrated in FIG. 10, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The lens L51 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The example illustrated in FIG. 11, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The lens L52 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, and the biconvex lens L23 that are arranged in order from the object side.
The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image surface side; and the cemented lens including the negative meniscus lens L34 having a concave surface facing the image surface side and the biconvex lens L35 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the positive meniscus lens L41 having a convex surface facing the object side.
The fifth lens group G5 includes the biconvex lens L51, the biconcave lens L52, a positive meniscus lens L53 having a convex surface facing the object side, and the biconvex lens L54 that are arranged in order from the object side.
The biconvex lens L51 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The sixth lens group G6 includes the negative meniscus lens L61 having a concave surface facing the object side.
Upon zooming from the wide angle end state to the telephoto end state, the distance between lens groups changes with the first lens group G1 to the fifth lens group G5 each moved toward the object side, and the sixth lens group G6 fixed.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, as illustrated in FIG. 10, image blur correction (vibration isolation) on the image surface I is performed with the lens L51 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is 0.38 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is 0.51 (mm). In the intermediate focal length state, the vibration proof coefficient is 0.49 and the focal length is 34.64 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is 0.57 (mm). In the telephoto end state, the vibration proof coefficient is 0.52 and the focal length is 58.22 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is 0.69 (mm).
In this Example, when image blur occurs, as illustrated in FIG. 11, image blur correction (vibration isolation) on the image surface I may be performed with the lens L52 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is −1.09 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.18 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.46 and the focal length is 34.64 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is −0.19 (mm). In the telephoto end state, the vibration proof coefficient is −1.58 and the focal length is 58.22 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is −0.23 (mm).
In Table 9 below, specification values in Example 9 are listed. Surface numbers 1 to 30 in Table 9 respectively correspond to the optical surfaces m1 to m30 in FIG. 10 (FIG. 11).







TABLE 9







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
49.45687
1.500
1.94594
18.0


2
36.05142
7.422
1.80400
46.6


3
182.73858
(D3) 
1.00000


4
62.21144
1.000
1.80400
46.6


5
11.36518
9.019
1.00000


*6
−34.02591
1.000
1.72903
54.0


*7
59.56235
0.635
1.00000


8
53.35980
2.208
1.94594
18.0


9
−520.59677
(D9) 
1.00000


*10
48.74985
3.200
1.72903
54.0


11
−39.98129
1.800
1.00000


12
(stop S)
1.500
1.00000


13
40.73217
3.600
1.48749
70.3


14
55.90792
1.000
1.78472
25.6


15
26.30167
1.200
1.00000


*16
53.91013
2.184
1.72903
54.0


17
14.60197
5.855
1.49782
82.6


18
−21.69065
(D18)
1.00000


19
42.13616
1.825
1.49782
82.6


20
237.39522
(D20)
1.00000


*21
47.17680
2.761
1.55332
71.7


*22
−706.53520
1.500
1.00000


23
−100.28754
1.000
1.82080
42.7


*24
23.18550
4.031
1.00000


25
31.73237
3.065
1.59319
67.9


26
115.97342
2.129
1.00000


27
33.27145
4.200
1.48749
70.3


28
−144.40572
(D28)
1.00000


29
−26.64822
0.900
1.71736
29.6


30
−33.43786
(D30)
1.00000


Img surface
∞










[Aspherical data]












Surface
κ
A4
A6
A8
A10





6
1.00000e+00
−4.69588e−05
3.57214e−07
−1.35769e−09 
−1.23340e−11


7
1.00000e+00
−6.31417e−05
4.33769e−07
−2.98689e−09 
 0.00000e+00


10
1.00000e+00
−3.33886e−05
−8.50862e−09 
6.57751e−11
−1.10130e−12


16
1.00000e+00
 3.56341e−05
2.95618e−08
4.30018e−10
−3.03421e−12


21
1.00000e+00
−4.67403e−05
−4.29180e−07 
6.51605e−09
−3.80050e−11


22
1.00000e+00
−5.25513e−05
−5.32941e−07 
1.01564e−08
−6.36780e−11


24
1.00000e+00
−3.65458e−06
5.64899e−08
−2.32781e−09 
 1.69874e−11










[Various data]


Zoom ratio 3.53













Wide angle

Telephoto




end
Intermediate
end







f
16.48
34.64
58.22



FNo
2.88
4.00
4.12



ω
40.8
22.4
13.8



Y
12.53
13.69
13.92



TL
106.299
122.339
144.292



BF
13.038
13.038
13.038



BF(air)
13.038
13.038
13.038












[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.48
34.64
58.22
—
—
—


β
—
—
—
−0.1003
−0.0840
−0.1283


D0
∞
∞
∞
143.70
377.66
405.71


D3
1.000
13.429
24.874
1.000
13.429
24.874


D9
18.736
5.550
0.800
18.736
5.550
0.800


D18
3.000
4.000
8.400
0.517
0.419
0.235


D20
2.622
8.667
16.304
5.105
12.247
24.469


D28
3.371
13.123
16.343
3.371
13.123
16.343


D30
13.038
13.038
13.038
13.038
13.038
13.038










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
89.38



Second lens group
4
−13.03



Third lens group
10
26.87



Fourth lens group
19
102.59



Fifth lens group
21
181.59



Sixth lens group
29
−193.67













[Conditional expression corresponding value]







Conditional expression(JC1) |fF/fRF| = 0.565



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.133



Conditional expression(JC3) Wω = 40.846



Conditional expression(JC4) Tω = 13.754



Conditional expression(JC5) fRF/fRF2 = −0.938



Conditional expression(JC6) DGXR/fXR = 0.757



Conditional expression(JD1) fV/fRF = 0.441(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.126(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JD2) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.176(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JD3) Wω = 40.846



Conditional expression(JD4) fF/fXR = 3.818



Conditional expression(JD5) (−fXn)/fXR = 0.485



Conditional expression(JD6) DGXR/fXR = 0.757



Conditional expression(JE1) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



Conditional expression(JE2) Wω = 40.846



Conditional expression(JE3) fF/fW = 6.224



Conditional expression(JE4) fV/fRF = 0.441(in the event that



the vibration-proof lens group comprises lens L51)



Conditional expression(JE5) fF/fXR = 3.818



Conditional expression(JE6) DGXR/fXR = 0.757



Conditional expression(JE7) DXnW/ZD1 = 0.436



Conditional expression(JF1) fF/fV = 1.282(in the event that



the vibration-proof lens group comprises lens L51)



fF/fV = −4.488(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JF2) fV/fRF = 0.441(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.126(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JF3) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.176(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JF4) Wω = 40.846



Conditional expression(JF5) fF/fXR = 3.818



Conditional expression(JF6) DGXR/fXR = 0.757



Conditional expression(JF7) TLW/ZD1 = 2.552



Conditional expression(JI1) (rB + rA)/(rB − rA) = 0.320



Conditional expression(JI2) (rC + rB)/(rC − rB) = 1.432



Conditional expression(JI3) |fF/fXR| = 3.818



Conditional expression(JI4) νdp = 82.570










It can be seen in Table 9 that the zoom optical system ZL9 according to Example 9 satisfies the conditional expressions (JC1) to (JC6), (JD1) to (JD6), (JE1) to (JE7), (JF1) to (JF7), and (JI1) to (JI4).
Example 10
Example 10 is described with reference to FIG. 12 and FIG. 13 and Table 10. A zoom optical system ZLI (ZL10) according to Example 10 includes, as illustrated in FIG. 12 (FIG. 13), the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having positive refractive power, and the sixth lens group G6 having negative refractive power that are arranged in order from the object side.
The example illustrated in FIG. 12, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The lens L51 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The example illustrated in FIG. 13, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The lens L52 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, and the biconvex lens L23 that are arranged in order from the object side.
The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image surface side; and the cemented lens including the negative meniscus lens L34 having a concave surface facing the image surface side and the biconvex lens L35 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the positive meniscus lens L41 having a convex surface facing the object side.
The fifth lens group G5 includes the biconvex lens L51, the biconcave lens L52, the positive meniscus lens L53 having a convex surface facing the object side, and the biconvex lens L54 that are arranged in order from the object side.
The biconvex lens L51 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The sixth lens group G6 includes the negative meniscus lens L61 having a concave surface facing the object side.
Upon zooming from the wide angle end state to the telephoto end state, the distance between lens groups changes with the first lens group G1 to the sixth lens group G6 each moved toward the object side.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, as illustrated in FIG. 12, image blur correction (vibration isolation) on the image surface I is performed with the lens L51 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is 0.38 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is 0.50 (mm). In the intermediate focal length state, the vibration proof coefficient is 0.51 and the focal length is 34.61 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is 0.54 (mm). In the telephoto end state, the vibration proof coefficient is 0.56 and the focal length is 58.20 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is 0.64 (mm).
In this Example, when image blur occurs, as illustrated in FIG. 13, image blur correction (vibration isolation) on the image surface I may be performed with the lens L52 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is −1.07 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.18 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.51 and the focal length is 34.61 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is −0.18 (mm). In the telephoto end state, the vibration proof coefficient is −1.66 and the focal length is 58.20 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is −0.22 (mm).
In Table 10 below, specification values in Example are listed. Surface numbers 1 to 30 in Table 10 respectively correspond to the optical surfaces m1 to m30 in FIG. 12 (FIG. 13).







TABLE 10







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
49.78243
1.500
1.94594
18.0


2
35.86372
7.402
1.80400
46.6


3
189.18021
(D3) 
1.00000


4
65.76146
1.000
1.80400
46.6


5
11.29701
9.472
1.00000


*6
−33.17281
1.000
1.72903
54.0


*7
76.05400
0.811
1.00000


8
77.87737
2.053
1.94594
18.0


9
−132.46424
(D9) 
1.00000


*10
47.23987
3.200
1.72903
54.0


11
−56.29315
1.800
1.00000


12
(stop S)
1.500
1.00000


13
27.78078
3.600
1.48749
70.3


14
56.24176
1.000
1.78472
25.6


15
27.11197
1.200
1.00000


*16
53.80018
2.710
1.72903
54.0


17
13.92675
5.537
1.49782
82.6


18
−25.09848
(D18)
1.00000


19
45.33900
1.837
1.49782
82.6


20
1599.96080
(D20)
1.00000


*21
45.65101
2.532
1.55332
71.7


*22
−1447.10910
1.500
1.00000


23
−452.24207
1.000
1.82080
42.7


*24
20.22114
2.400
1.00000


25
28.39789
2.688
1.59319
67.9


26
71.92350
4.215
1.00000


27
27.16600
4.200
1.48749
70.3


28
−4665.16500
(D28)
1.00000


29
−38.79932
0.900
1.71736
29.6


30
−56.54936
(D30)
1.00000


Img surface
∞










[Aspherical data]












Surface
κ
A4
A6
A8
A10





6
1.00000e+00
−4.94676e−05
3.71757e−07
−1.44242e−09 
−1.29921e−11


7
1.00000e+00
−6.87910e−05
4.47896e−07
−3.21751e−09 
 0.00000e+00


10
1.00000e+00
−2.34156e−05
−1.78545e−08 
2.23796e−10
−2.47091e−12


16
1.00000e+00
 2.60151e−05
1.85464e−08
4.45711e−10
−2.73163e−12


21
1.00000e+00
−5.37696e−05
−4.53146e−07 
5.81104e−09
−3.49284e−11


22
1.00000e+00
−6.07160e−05
−5.10190e−07 
8.74421e−09
−5.59878e−11


24
1.00000e+00
−3.13598e−06
3.51177e−08
−2.23705e−09 
 1.68047e−11










[Various data]


Zoom ratio 3.53













Wide angle

Telephoto




end
Intermediate
end







f
16.48
34.61
58.20



FNo
2.88
4.00
4.12



ω
40.8
22.4
13.8



Y
12.52
13.61
13.91



TL
106.296
122.654
142.974



BF
13.035
13.326
20.633



BF(air)
13.035
13.326
20.633












[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.48
34.61
58.20
—
—
—


β
—
—
—
−0.1004
−0.1450
−0.1279


D0
∞
∞
∞
143.70
207.35
407.03


D3
1.000
12.229
24.863
1.000
12.229
24.863


D9
18.828
5.162
0.800
18.828
5.162
0.800


D18
3.000
6.584
7.754
0.633
0.720
0.369


D20
2.518
6.412
13.599
4.885
12.275
20.984


D28
2.858
13.885
10.268
2.858
13.885
10.268


D30
13.035
13.326
20.633
13.035
13.326
20.633










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
89.47



Second lens group
4
−13.41



Third lens group
10
27.83



Fourth lens group
19
93.69



Fifth lens group
21
216.45



Sixth lens group
29
−176.04













[Conditional expression corresponding value]







Conditional expression(JB1) (DMRT − DMRW)/fF = 0.118



Conditional expression(JB2) Wω = 40.847



Conditional expression(JB3) Tω = 13.758



Conditional expression(JB4) fF/fRF = 0.433



Conditional expression(JB5) fF/fXR = 3.367



Conditional expression(JB6) DGXR/fXR = 0.738



Conditional expression(JC1) |fF/fRF| = 0.433



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.118



Conditional expression(JC3) Wω = 40.847



Conditional expression(JC4) Tω = 13.758



Conditional expression(JC5) fRF/fRF2 = −1.230



Conditional expression(JC6) DGXR/fXR = 0.738



Conditional expression(JD1) fV/fRF = 0.370(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.109(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JD2) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.102(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JD3) Wω = 40.847



Conditional expression(JD4) fF/fXR = 3.367



Conditional expression(JD5) (−fXn)/fXR = 0.482



Conditional expression(JD6) DGXR/fXR = 0.738



Conditional expression(JE1) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.102(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JE2) Wω = 40.847



Conditional expression(JE3) fF/fW = 5.685



Conditional expression(JE4) fV/fRF = 0.370(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.109(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JE5) fF/fXR = 3.367



Conditional expression(JE6) DGXR/fXR = 0.738



Conditional expression(JE7) DXnW/ZD1 = 0.496



Conditional expression(JF1) fF/fV = 1.171(in the event that



the vibration-proof lens group comprises lens L51)



fF/fV = −3.977(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JF2) fV/fRF = 0.370(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.109(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JF3) DVW/fV = 0.019(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.102(in the event that



the vibration-proof lens group comprises lens L52)



Conditional expression(JF4) Wω = 40.847



Conditional expression(JF5) fF/fXR = 3.367



Conditional expression(JF6) DGXR/fXR = 0.738



Conditional expression(JF7) TLW/ZD1 = 2.798



Conditional expression(JI1) (rB + rA)/(rB − rA) = 0.287



Conditional expression(JI2) (rC + rB)/(rC − rB) = 1.058



Conditional expression(JI3) |fF/fXR| = 3.367



Conditional expression(JI4) νdp = 82.570










It can be seen in Table 10 that the zoom optical system ZL10 according to Example 10 satisfies the conditional expressions (JB1) to (JB6), (JC1) to (JC6), (JD1) to (JD6), (JE1) to (JE7), (JF1) to (JF7), and (JI1) to (JI4).
Example 11
Example 11 is described with reference to FIG. 14 and FIG. 15 and Table 11. A zoom optical system ZLI (ZL11) according to Example 11 includes, as illustrated in FIG. 14 (FIG. 15), the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having positive refractive power, and the sixth lens group G6 having negative refractive power that are arranged in order from the object side.
The example illustrated in FIG. 14, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The fifth lens group G5 corresponds to the vibration-proof lens group VR.
The example illustrated in FIG. 15, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The lens L61 forming the sixth lens group G6 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, and the biconvex lens L23 that are arranged in order from the object side.
The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image surface side; and the cemented lens including the negative meniscus lens L34 having a concave surface facing the image surface side and the biconvex lens L35 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the positive meniscus lens L41 having a convex surface facing the object side.
The fifth lens group G5 includes the positive meniscus lens L51 having a convex surface facing the object side.
The positive meniscus lens L51 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The sixth lens group G6 includes a biconcave lens L61; a positive meniscus lens L62 having a convex surface facing the object side; a positive meniscus lens L63 having a convex surface facing the object side; and a biconcave lens L64 that are arranged in order from the object side.
The biconcave lens L61 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
Upon zooming from the wide angle end state to the telephoto end state, the distance between lens groups changes with the first lens group G1 to the sixth lens group G6 each moved toward the object side.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, as illustrated in FIG. 14, image blur correction (vibration isolation) on the image surface I is performed with the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is 0.37 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is 0.52 (mm). In the intermediate focal length state, the vibration proof coefficient is 0.48 and the focal length is 34.55 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is 0.58 (mm). In the telephoto end state, the vibration proof coefficient is 0.55 and the focal length is 58.20 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is 0.65 (mm).
In this Example, when image blur occurs, as illustrated in FIG. 15, image blur correction (vibration isolation) on the image surface I may be performed with the lens L61 forming the sixth lens group G6 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is −1.20 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.16 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.63 and the focal length is 34.55 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is −0.17 (mm). In the telephoto end state, the vibration proof coefficient is −1.92 and the focal length is 58.20 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is −0.19 (mm).
In Table 11 below, specification values in Example are listed. Surface numbers 1 to 30 in Table 11 respectively correspond to the optical surfaces m1 to m30 in FIG. 14 (FIG. 15).







TABLE 11







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
52.30855
1.500
1.94594
18.0


2
37.33284
7.071
1.80400
46.6


3
216.54215
(D3) 
1.00000


4
61.38788
1.000
1.80400
46.6


5
11.65182
9.233
1.00000


*6
−32.14862
1.000
1.72903
54.0


*7
74.53588
1.024
1.00000


8
60.50694
2.193
1.94594
18.0


9
−258.79475
(D9) 
1.00000


*10
46.01441
3.200
1.72903
54.0


11
−56.40981
1.800
1.00000


12
(stop S)
1.500
1.00000


13
29.53961
2.255
1.51860
69.9


14
62.01786
1.000
1.78472
25.6


15
28.20544
1.200
1.00000


*16
55.69244
0.900
1.72903
54.0


17
15.23446
7.773
1.49782
82.6


18
−19.05606
(D18)
1.00000


19
36.98318
1.625
1.49782
82.6


20
105.10268
(D20)
1.00000


*21
43.20902
2.199
1.55332
71.7


*22
1751.40520
(D22)
1.00000


23
−171.60024
1.000
1.82080
42.7


*24
17.59425
2.400
1.00000


25
26.33835
2.542
1.48749
70.3


26
72.49985
3.966
1.00000


27
25.12670
4.200
1.48749
70.3


28
221.49212
0.920
1.00000


29
−248.05584
0.900
1.71736
29.6


30
676.75372
(D30)
1.00000


Img surface
∞










[Aspherical data]












Surface
κ
A4
A6
A8
A10





6
1.00000e+00
−5.77765e−05
 3.44287e−07
−6.22102e−10 
−1.57242e−11


7
1.00000e+00
−6.99357e−05
 4.62841e−07
−2.74060e−09 
 0.00000e+00


10
1.00000e+00
−2.68855e−05
−4.61691e−08
5.50569e−11
−1.70214e−12


16
1.00000e+00
 1.11787e−05
 5.00773e−08
1.88833e−10
−7.71465e−15


21
1.00000e+00
−5.10052e−05
−6.02110e−07
6.11612e−09
−6.10307e−11


22
1.00000e+00
−6.30677e−05
−4.65571e−07
4.57749e−09
−4.89754e−11


24
1.00000e+00
−1.61208e−06
−1.18039e−07
4.93252e−10
 5.31842e−13










[Various data]


Zoom ratio 3.53













Wide angle

Telephoto




end
Intermediate
end







f
16.48
34.55
58.20



FNo
2.88
4.00
4.12



ω
40.8
22.4
13.8



Y
12.54
13.83
14.06



TL
102.322
116.417
135.956



BF
13.054
22.464
28.774



BF(air)
13.054
22.464
28.774












[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.48
34.55
58.20
—
—
—


β
—
—
—
−0.0977
−0.1271
−0.1908


D0
∞
∞
∞
147.68
233.58
244.04


D3
1.000
13.610
25.000
1.000
13.610
25.000


D9
18.408
5.666
0.800
18.408
5.666
0.800


D18
3.000
4.809
11.304
0.806
0.661
2.678


D20
2.759
5.833
6.177
4.952
9.982
14.803


D22
1.700
1.633
1.500
1.700
1.633
1.500


D30
13.054
22.464
28.774
13.054
22.464
28.774










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
91.89



Second lens group
4
−13.83



Third lens group
10
24.94



Fourth lens group
19
113.72



Fifth lens group
21
80.03



Sixth lens group
23
−46.99













[Conditional expression corresponding value]







Conditional expression(JB1) (DMRT − DMRW)/fF = 0.030



Conditional expression(JB2) Wω = 40.846



Conditional expression(JB3) Tω = 13.758



Conditional expression(JB4) fF/fRF = 1.421



Conditional expression(JB5) fF/fXR = 4.559



Conditional expression(JB6) DGXR/fXR = 0.787



Conditional expression(JC1) |fF/fRF| = 1.421



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.030



Conditional expression(JC3) Wω = 40.846



Conditional expression(JC4) Tω = 13.758



Conditional expression(JC5) fRF/fRF2 = −1.703



Conditional expression(JC6) DGXR/fXR = 0.787



Conditional expression(JD1) fV/fRF = −0.242(in the event that



the vibration-proof lens group comprises lens L61)



Conditional expression(JD2) DVW/fV = −0.124(in the event that



the vibration-proof lens group comprises lens L61)



Conditional expression(JD3) Wω = 40.846



Conditional expression(JD4) fF/fXR = 4.559



Conditional expression(JD5) (−fXn)/fXR = 0.554



Conditional expression(JD6) DGXR/fXR = 0.787



Conditional expression(JE1) DVW/fV = 0.021(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.124(in the event that



the vibration-proof lens group comprises lens L61)



Conditional expression(JE2) Wω = 40.846



Conditional expression(JE3) fF/fW = 6.900



Conditional expression(JE4) fV/fRF = 1.000(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.242(in the event that



the vibration-proof lens group comprises lens L61)



Conditional expression(JE5) fF/fXR = 4.559



Conditional expression(JE6) DGXR/fXR = 0.787



Conditional expression(JE7) DXnW/ZD1 = 0.502



Conditional expression(JF1) fF/fV = 1.421(in the event that



the vibration-proof lens group comprises lens L51)



fF/fV = −5.863(in the event that



the vibration-proof lens group comprises lens L61)



Conditional expression(JF2) fV/fRF = 1.000(in the event that



the vibration-proof lens group comprises lens L51)



fV/fRF = −0.242(in the event that



the vibration-proof lens group comprises lens L61)



Conditional expression(JF3) DVW/fV = 0.021(in the event that



the vibration-proof lens group comprises lens L51)



DVW/fV = −0.124(in the event that



the vibration-proof lens group comprises lens L61)



Conditional expression(JF4) Wω = 40.846



Conditional expression(JF5) fF/fXR = 4.559



Conditional expression(JF6) DGXR/fXR = 0.787



Conditional expression(JF7) TLW/ZD1 = 2.898



Conditional expression(JI1) (rB + rA)/(rB − rA) = 0.320



Conditional expression(JI2) (rC + rB)/(rC − rB) = 1.043



Conditional expression(JI3) |fF/fXR| = 4.559



Conditional expression(JI4) νdp = 82.570










It can be seen in Table 11 that the zoom optical system ZL11 according to Example 11 satisfies the conditional expressions (JB1) to (JB6), (JC1) to (JC6), (JD1) to (JD6), (JE1) to (JE7), (JF1) to (JF7), and (JI1) to (JI4).
Example 12
Example 12 is described with reference to FIG. 16 and Table 12. A zoom optical system ZLI (ZL12) according to Example 12 includes, as illustrated in FIG. 16, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having positive refractive power, and the sixth lens group G6 having negative refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 and the sixth lens group G6 correspond to the rear-side lens group GR. The fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, and the biconvex lens L23 that are arranged in order from the object side.
The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image surface side; and the cemented lens including the negative meniscus lens L34 having a concave surface facing the image surface side and the biconvex lens L35 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconvex lens L41.
The fifth lens group G5 includes a negative meniscus lens L51 having a concave surface facing the image surface side; a negative meniscus lens L52 having a concave surface facing the object side; the positive meniscus lens L53 having a convex surface facing the image surface side; and a positive meniscus lens L54 having a convex surface facing the image surface side that are arranged in order from the object side.
The negative meniscus lens L51 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape. The positive meniscus lens L53 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The sixth lens group G6 includes the negative meniscus lens L61 having a concave surface facing the object side.
Upon zooming from the wide angle end state to the telephoto end state, the distance between lens groups changes with the first lens group G1 to the fourth lens group G4 each moved toward the object side, the fifth lens group G5 moved toward the image surface side, and the sixth lens group G6 fixed.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In the wide angle end state, the vibration proof coefficient is 0.23 and the focal length is 16.48 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is 0.81 (mm). In the intermediate focal length state, the vibration proof coefficient is 0.23 and the focal length is 34.23 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.46° is 1.21 (mm). In the telephoto end state, the vibration proof coefficient is 0.20 and the focal length is 58.22 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.35° is 1.79 (mm).
In Table 12 below, specification values in Example are listed. Surface numbers 1 to 30 in Table 12 respectively correspond to the optical surfaces m1 to m30 in FIG. 16.







TABLE 12







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
46.40832
1.500
1.94594
18.0


2
34.66455
6.713
1.80400
46.6


3
127.07483
(D3) 
1.00000


4
55.81938
1.000
1.80400
46.6


5
11.58349
9.722
1.00000


*6
−46.86550
1.000
1.72903
54.0


*7
51.87909
0.783
1.00000


8
59.79626
2.014
1.94594
18.0


9
−2186.07280
(D9) 
1.00000


*10
27.26861
3.200
1.72903
54.0


11
−129.16671
1.800
1.00000


12
(stop S)
1.500
1.00000


13
68.38177
2.869
1.48749
70.3


14
202.75413
1.000
1.78472
25.6


15
39.83391
1.200
1.00000


*16
142.37742
0.850
1.72903
54.0


17
16.28016
4.757
1.49782
82.6


18
−23.81991
(D18)
1.00000


19
34.83439
2.380
1.49782
82.6


20
−181.29602
(D20)
1.00000


*21
318.18531
2.000
1.69350
53.2


22
79.44709
2.209
1.00000


23
−45.33154
1.000
1.77377
47.2


*24
−60.05145
7.053
1.00000


*25
−1295.54840
5.000
1.59255
67.9


26
−26.79305
1.384
1.00000


27
−28.73919
4.200
1.59319
67.9


28
−20.59136
(D28)
1.00000


29
−30.60749
0.850
1.80809
22.7


30
−206.61166
(D30)
1.00000


Img surface
∞










[Aspherical data]












Surface
κ
A4
A6
A8
A10





6
1.00000e+00
−4.29550e−05
2.50726e−07
−1.33649e−09 
−9.20595e−12 


7
1.00000e+00
−6.40436e−05
3.01735e−07
−2.60073e−09 
0.00000e+00


10
1.00000e+00
−1.85190e−05
−4.30274e−09 
−2.14140e−10 
6.29617e−13


16
1.00000e+00
 1.21548e−05
−3.28136e−08 
1.45941e−09
−1.15076e−11 


21
1.00000e+00
−2.85327e−05
8.17418e−08
1.11021e−09
0.00000e+00


24
1.00000e+00
−3.56325e−05
1.57588e−07
3.97044e−10
5.59729e−12


25
1.00000e+00
−4.55529e−05
4.82262e−08
1.53635e−10
0.00000e+00










[Various data]


Zoom ratio 3.53













Wide angle

Telephoto




end
Intermediate
end







f
16.48
34.23
58.22



FNo
2.88
3.99
4.49



ω
40.8
22.0
13.0



Y
13.01
14.25
14.25



TL
106.751
122.797
143.722



BF
12.997
12.997
12.997



BF(air)
12.997
12.997
12.997












[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.48
34.23
58.22
—
—
—


β
—
—
—
−0.1012
−0.1708
−0.1329


D0
∞
∞
∞
143.25
177.20
406.28


D3
1.000
10.016
25.000
1.000
10.016
25.000


D9
18.296
5.240
0.800
18.296
5.240
0.800


D18
3.000
6.945
6.827
1.247
1.855
0.461


D20
2.354
18.768
30.128
4.107
23.857
36.495


D28
3.120
2.848
1.986
3.120
2.848
1.986


D30
12.997
12.997
12.997
12.997
12.997
12.997










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
95.15



Second lens group
4
−13.63



Third lens group
10
31.54



Fourth lens group
19
58.91



Fifth lens group
21
42.02



Sixth lens group
29
−44.56













[Conditional expression corresponding value]







Conditional expression(JA1) |fF/fRF| = 1.402



Conditional expression(JA2) (−fXn)/fXR = 0.432



Conditional expression(JA3) fF/fW = 3.575



Conditional expression(JA4) Wω = 40.848



Conditional expression(JA5) fF/fXR = 1.868



Conditional expression(JA6) DXRFT/fF = 0.116



Conditional expression(JA7) Tω = 13.014



Conditional expression(JA8) DGXR/fXR = 0.619



Conditional expression(JC1) |fF/fRF| = 1.402



Conditional expression(JC2) (DMRT − DMRW)/fF = 0.471



Conditional expression(JC3) Wω = 40.848



Conditional expression(JC4) Tω = 13.014



Conditional expression(JC5) fRF/fRF2 = −0.943



Conditional expression(JC6) DGXR/fXR = 0.545



Conditional expression(JE1) DVW/fV = 0.074



Conditional expression(JE2) Wω = 40.848



Conditional expression(JE3) fF/fW = 3.575



Conditional expression(JE4) fV/fRF = 1.000



Conditional expression(JE5) fF/fXR = 1.868



Conditional expression(JE6) DGXR/fXR = 0.545



Conditional expression(JE7) DXnW/ZD1 = 0.544



Conditional expression(JF1) fF/fV = 1.402



Conditional expression(JF2) fV/fRF = 1.000



Conditional expression(JF3) DVW/fV = 0.074



Conditional expression(JF4) Wω = 40.848



Conditional expression(JF5) fF/fXR = 1.868



Conditional expression(JF6) DGXR/fXR = 0.545



Conditional expression(JF7) TLW/ZD1 = 3.042



Conditional expression(JI1) (rB + rA)/(rB − rA) = 0.188



Conditional expression(JI2) (rC + rB)/(rC − rB) = 0.678



Conditional expression(JI3) |fF/fXR| = 1.868



Conditional expression(JI4) νdp = 82.570










It can be seen in Table 12 that the zoom optical system ZL12 according to Example 12 satisfies the conditional expressions (JA1) to (JA8), (JC1) to (JC6), (JE1) to (JE7), (JF1) to (JF7), and (JI1) to (JI4).
Example 13
Example 13 is described with reference to FIG. 17 and Table 13. A zoom optical system ZLI (ZL13) according to Example 13 includes, as illustrated in FIG. 17, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 having negative refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 and the third lens group G3 correspond to the front-side lens group GX. The fourth lens group G4 corresponds to the intermediate lens group GM (focusing lens group GF). The fifth lens group G5 corresponds to the rear-side lens group GR. The cemented lens including the lenses L51 and L52 forming the fifth lens group G5 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image surface side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image surface side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side.
The negative meniscus lens L21 is a composite type aspherical lens with a resin layer, formed on a glass surface on the object side, formed to have an aspherical shape. The negative meniscus lens L24 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The third lens group G3 includes: the biconvex lens L31; the aperture stop S; the cemented lens including the negative meniscus lens L32 having a concave surface facing the image surface side and the biconvex lens L33; the biconvex lens L34; and the cemented lens including the biconvex lens L35 and the biconcave lens L36 that are arranged in order from the object side.
The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side.
The fifth lens group G5 includes: the cemented lens including the positive meniscus lens L51 having a convex surface facing the image surface side and the biconcave lens L52; the biconvex lens L53; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The biconcave lens L52 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
Upon zooming from the wide angle end state to the telephoto end state, the distance between lens groups changes with the first lens group G1 to the fifth lens group G5 each moved toward the object side.
Upon focusing from infinity to the short-distant object, the fourth lens group G4 moves toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the cemented lens including the lenses L51 and L52 forming the fifth lens group G5, and serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In Example 13, in the wide angle end state, the vibration proof coefficient is −0.97 and the focal length is 24.70 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.66° is −0.29 (mm). In the intermediate focal length state, the vibration proof coefficient is −1.23 and the focal length is 49.50 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.47° is −0.33 (mm). In the telephoto end state, the vibration proof coefficient is −1.48 and the focal length is 82.45 (mm), and thus the movement amount of the vibration-proof lens group VR for correcting the roll blur of 0.36° is −0.35 (mm).
In Table 13 below, specification values in Example are listed. Surface numbers 1 to 35 in Table 13 respectively correspond to the optical surfaces m1 to m35 in FIG. 17.







TABLE 13







[Lens specifications]











Surface number
R
D
nd
νd





Obj surface
∞


1
241.11515
2.000
1.92286
20.9


2
103.44771
5.420
1.59319
67.9


3
−7416.50890
0.100
1.00000


4
56.35289
5.617
1.75500
52.3


5
189.71095
(D5) 
1.00000


*6
180.45884
0.100
1.56093
36.6


7
93.90256
1.250
1.83481
42.7


8
15.53782
8.861
1.00000


9
−29.30755
1.000
1.80400
46.6


10
125.24231
0.299
1.00000


11
56.49561
5.857
1.80809
22.7


12
−29.68309
1.683
1.00000


13
−20.94818
1.200
1.88202
37.2


*14
−36.26558
(D14)
1.00000


*15
208.43307
2.148
1.72903
54.0


16
−111.63066
2.282
1.00000


17
(stop S)
1.000
1.00000


18
46.77320
1.500
1.71999
50.3


19
31.72866
5.122
1.49782
82.6


20
−453.18879
0.100
1.00000


21
76.84303
4.093
1.48749
70.3


22
−45.25442
0.100
1.00000


23
263.80748
4.141
1.95000
29.4


24
−31.17139
1.000
1.79504
28.7


25
29.03381
(D25)
1.00000


26
55.64853
5.981
1.58313
59.4


27
−19.40195
1.000
1.79504
28.7


28
−35.38084
(D28)
1.00000


29
−141.22564
3.677
1.84666
23.8


30
−23.75223
1.000
1.76801
49.2


*31
43.50066
3.075
1.00000


32
44.96093
8.708
1.49782
82.6


33
−21.83258
0.911
1.00000


34
−21.94603
1.350
1.90366
31.3


35
−48.91548
(D35)
1.00000


Img surface
∞












[Aspherical data]







6th surface



κ = 1.00000e+00



A4 = 1.29884e−05



A6 = −2.61296e−08



A8 = 6.74064e−11



A10 = −1.41771e−13



A12 = 2.18700e−16



14th surface



κ = 1.00000e+00



A4 = −1.60620e−06



A6 = −8.46210e−09



A8 = 1.06446e−12



A10 = 0.00000e+00



A12 = 0.00000e+00



15th surface



κ = 1.00000e+00



A4 = −9.77451e−06



A6 = −5.03316e−09



A8 = −7.08144e−12



A10 = 0.00000e+00



A12 = 0.00000e+00



31st surface



κ = 1.00000e+00



A4 = 4.03997e−07



A6 = −2.51998e−09



A8 = 2.61375e−11



A10 = 0.00000e+00



A12 = 0.00000e+00











[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.70
49.50
82.45



FNo
3.08
3.85
4.60



ω
41.2
23.6
14.4



Y
19.46
21.63
21.63



TL
157.364
172.583
196.763



BF
38.000
51.002
63.987



BF(air)
38.000
51.002
63.987











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.70
49.50
82.45
—
—
—


β
—
—
—
−0.1467
−0.1894
−0.2422


D0
∞
∞
∞
142.64
227.42
303.24


D5
1.500
14.906
29.804
1.500
14.906
29.804


D14
24.244
7.638
1.500
24.244
7.638
1.500


D25
11.046
9.677
11.046
9.229
5.570
2.629


D28
2.000
8.785
9.851
3.817
12.891
18.268


D35
38.000
51.002
63.987
38.000
51.002
63.987










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
97.37



Second lens group
6
−17.47



Third lens group
15
48.40



Fourth lens group
26
46.36



Fifth lens group
29
−128.60













[Conditional expression corresponding value]







Conditional expression(JB1) (DMRT − DMRW)/fF = 0.169



Conditional expression(JB2) Wω = 41.170



Conditional expression(JB3) Tω = 14.419



Conditional expression(JB4) fF/fRF = −0.361



Conditional expression(JB5) fF/fXR = 0.958



Conditional expression(JB6) DGXR/fXR = 0.444



Conditional expression(JD1) fV/fRF = 0.379



Conditional expression(JD2) DVW/fV = −0.063



Conditional expression(JD3) Wω = 41.170



Conditional expression(JD4) fF/fXR = 0.958



Conditional expression(JD5) (−fXn)/fXR = 0.361



Conditional expression(JD6) DGXR/fXR = 0.444



Conditional expression(JE1) DVW/fV = −0.063



Conditional expression(JE2) Wω = 41.170



Conditional expression(JE3) fF/fW = 1.877



Conditional expression(JE4) fV/fRF = 0.379



Conditional expression(JE5) fF/fXR = 0.958



Conditional expression(JE6) DGXR/fXR = 0.444



Conditional expression(JE7) DXnW/ZD1 = 0.721



Conditional expression(JG1) βFt = −0.247



Conditional expression(JG2) (rB + rA)/(rB − rA) = 3.182



Conditional expression(JG3) βFw = 0.163



Conditional expression(JH1) (rB + rA)/(rB − rA) = 3.182



Conditional expression(JH2) (rC + rB)/(rC − rB) = −0.223



Conditional expression(JH3) |fF/fXR| = 0.958



Conditional expression(JH4) βFw = 0.163



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 3.182



Conditional expression(JJ2) |fF/fXR| = 0.958



Conditional expression(JJ3) βFw = 0.163



Conditional expression(JJ4) νdn = 28.690










It can be seen in Table 13 that the zoom optical system ZL13 according to Example 13 satisfies the conditional expressions (JB1) to (JB6), (JD1) to (JD6), (JE1) to (JE7), (JG1) to (JG3), (JH1) to (JH4), and (JJ1) to (JJ4).
Example 14
Example 14 is described with reference to FIG. 18 and Table 14. A zoom optical system ZLI (ZL14) according to Example 14 includes, as illustrated in FIG. 18, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
In the present example, the second lens group G2 corresponds to the front-side lens group GX. The third lens group G3 corresponds to the intermediate lens group GM. The third lens group G3 includes an object side group GA and an image side group GB that are arranged in order from the object side, and the image side group GB corresponds to the focusing lens group GF. The fourth lens group G4 and the fifth lens group G5 correspond to the rear-side lens group GR. The fourth lens group G4 corresponds to the vibration-proof lens group VR.
The first lens group G1 includes: a cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from the object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes the biconvex lens L31, the aperture stop S, a biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L34 and a negative meniscus lens L35 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the positive meniscus lens L41 having a convex surface facing the image surface side and a biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; a cemented lens including a positive meniscus lens L52 having a convex surface facing the image side and a negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side; and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side, in such a manner that the distance between the first lens group G1 and the second lens group G2 increases and the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB forming the third lens group G3, serving as the focusing lens group GF, moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis.
In Example 14, in the wide angle end state, the shifted amount of the vibration-proof lens group is −0.338 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group is −0.358 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group is −0.389 mm when the correction angle is 0.327°.
In Table 14 below, specification values in Example are listed. Surface numbers 1 to 33 in Table 14 respectively correspond to the optical surfaces m1 to m33 in FIG. 18.







TABLE 14







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
755.7151
2.00
22.74
1.80809


2
161.3459
5.78
67.90
1.59319


3
−580.4059
0.10


4
67.8395
5.80
54.61
1.72916


5
174.6045
 D5(variable)


6
76.4442
1.35
35.73
1.90265


7
18.5155
8.86


*8
−39.7788
1.00
51.15
1.75501


9
52.4007
0.10


10
40.3224
5.17
22.74
1.80809


11
−52.2736
2.86


12
−23.0648
1.20
58.12
1.62299


13
−42.3507
D13(variable)


*14
38.7318
3.48
51.15
1.75501


*15
−132.1314
1.00


16
∞
2.50
(aperture stop)


17
46.8922
5.22
82.57
1.49782


18
−42.6707
0.10


19
755.7937
1.00
37.18
1.83400


20
25.3493
D20(variable)


*21
32.5284
7.45
67.02
1.59201


22
−21.4485
1.00
23.80
1.84666


23
−37.3054
D23(variable)


24
−269.6872
4.53
22.74
1.80809


25
−22.2495
1.00
35.25
1.74950


26
33.9362
D26(variable)


27
39.0406
8.96
81.49
1.49710


28
−26.9857
1.06


29
−31.8633
4.36
22.74
1.80809


30
−27.4771
1.35
52.34
1.75500


31
−56.0731
3.74


32
−21.6584
1.30
54.61
1.72916


33
−45.4890
D33(variable)


Img surface
∞










[Aspherical data]












Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 4.46184E−06
6.59185E−09
−2.42201E−11
2.59662E−13


14th surface
0.00
−3.88209E−06
2.73780E−08
−1.55431E−10
0.00000E+00


15th surface
0.00
 7.82327E−06
2.51863E−08
−1.15048E−10
−1.28188E−13 


21st surface
0.00
−3.14303E−06
5.83544E−10
−1.13942E−11
0.00000E+00










[Various data]


Zoom ratio 4.13













Wide angle

Telephoto




end
Intermediate
end







f
24.7~
49.5~
102.0



FNo
2.9~
3.7~
4.1



2ω
82.4~
47.2~
23.5



Y
19.2~
21.6~
21.6



TL(air)
145.2~
160.9~
196.8



BF(air)
14.9~
28.9~
43.9











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
102.0
24.7
49.5
102.0


D5
1.10
19.44
48.07


D13
25.53
8.90
1.10


D20
10.87
10.87
10.87
10.20
8.66
2.09


D23
2.50
6.70
7.68
3.17
8.91
16.46


D26
8.08
3.88
2.90


D33
14.92
28.89
43.95










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
133.47



Second lens group
6
−20.32



Third lens group
14
30.32



Fourth lens group
24
−44.25



Fifth lens group
27
151.19













[Conditional expression corresponding value]







Conditional expression(JG1) βFt = −0.306



Conditional expression(JG2) (rB + rA)/(rB − rA) = 8.062



Conditional expression(JG3) βFw = 0.085



Conditional expression(JJ1) (rB + rA)/(rB − rA) = 8.062



Conditional expression(JJ2) |fF/fXR| = 1.760



Conditional expression(JJ3) βFw = 0.085



Conditional expression(JJ4) νdn = 23.800










It can be seen in Table 14 that the zoom optical system ZL14 according to this Example satisfies the conditional expression (JG1) to (JG3) and (JJ1) to (JJ4).
Examples described above can achieve the zoom optical system featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Elements of the embodiments are described above to facilitate the understanding of the present invention. It is a matter of course that the present invention is not limited to these. The following configurations can be appropriately employed without compromising the optical performance of the zoom optical system according to the present application.
The present invention further includes sub combinations of feature groups of Examples.
The numerical values of the configuration with the five groups or six groups are described as an example of values of the zoom optical system ZLI according to the 1st to the 6th embodiments. However, this should not be construed in a limiting sense, and the present invention can be applied to a configuration with other number of groups (for example, seven groups or the like). More specifically, a configuration further provided with a lens or a lens group closest to an object or further provided with a lens or a lens group closest to the image may be employed. The first to the sixth lens groups, the front-side lens group, the intermediate lens group, and the rear-side lens group are each a portion including at least one lens separated from another lens with a distance varying upon zooming. The focusing lens group GF is a portion including at least one lens separated from another lens with a distance varying upon focusing. The vibration-proof lens group is a portion including at least one lens and is defined by a portion that moves upon image stabilization and a portion that does not move upon image stabilization.
In the zoom optical system ZLI according to the 1st to the 6th embodiment may have the following configuration. Specifically, upon focusing on a short-distant object from infinity, part of a lens group, one entire lens group, or a plurality of lens groups may be moved in the optical axis direction as the focusing lens group GF. The focusing lens group GF may be applied to auto focusing, and can be suitably driven by a motor (such as an ultrasonic motor for example) for auto focusing. At least part of the fourth lens group G4 is especially preferably used as the focusing lens group GF.
In the zoom optical system ZLI according to the 1st to the 6th embodiments, any of the lens group may be entirely or partially moved with a component in a direction orthogonal to the optical axis, or may be moved and rotated (swing) within an in-plane direction including the optical axis, to serve as the vibration-proof lens group for correcting image blur due to camera shake or the like. At least part of the fifth lens group G5 or at least part of the sixth lens group G6 is especially preferably used as the vibration-proof lens group.
In the zoom optical system ZLI according to the 1st to the 6th embodiments, the lens surface may be formed to have a spherical surface or a planer surface, or may be formed to have an aspherical shape. The lens surface having a spherical surface or a planer surface features easy lens processing and assembly adjustment, which leads to the processing and assembly adjustment less likely to involve an error compromising the optical performance, and thus is preferable. Furthermore, there is an advantage that a rendering performance is not largely compromised even when the image surface is displaced. The lens surface having an aspherical shape may be achieved with any one of an aspherical shape formed by grinding, a glass-molded aspherical shape obtained by molding a glass piece into an aspherical shape, and a composite type aspherical surface obtained by providing an aspherical shape resin piece on a glass surface. A lens surface may be a diffractive surface. The lens may be a gradient index lens (GRIN lens) or a plastic lens.
In the zoom optical system ZLI according to the 1st to the 6th embodiments, the aperture stop S is preferably disposed in the neighborhood of the third lens group G3. Alternatively, a lens frame may serve as the aperture stop so that the member serving as the aperture stop needs not to be provided.
In the zoom optical system ZLI according to the 1st to the 6th embodiments, the lens surfaces may be provided with an antireflection film featuring high transmittance over a wide range of wavelengths to achieve an excellent optical performance with reduced flare and ghosting and increased contract.
The zoom optical system ZLI according to the 1st to the 6th embodiment has a zooming rate of about 300 to 450%.
The numerical values of the configuration with the five groups or six groups are described as an example of values of the zoom optical system ZLI according to the 7th to 10th embodiments. However, this should not be construed in a limiting sense, and the present invention can be applied to a configuration with other number of groups (for example, seven groups or the like). More specifically, a configuration further provided with a lens or a lens group closest to an object or further provided with a lens or a lens group closest to the image surface may be employed. The first to the sixth lens groups, the front-side lens group, the intermediate lens group, and the rear-side lens group are each a portion including at least one lens separated from another lens with a distance varying upon zooming. The focusing lens group GF is a portion including at least one lens separated from another lens with a distance varying upon focusing. The vibration-proof lens group is a portion including at least one lens and is defined by a portion that moves upon image stabilization and a portion that does not move upon image stabilization.
In the zoom optical system ZLI according to the 7th to the 10th embodiments may have the following configuration. Specifically, upon focusing on a short-distant object from infinity, part of a lens group, one entire lens group, or a plurality of lens groups may be moved in the optical axis direction as the focusing lens group GF. The focusing lens group GF may be applied to auto focusing, and can be suitably driven by a motor (such as an ultrasonic motor, a stepping motor, or a voice coil motor for example) for auto focusing. At least part of the third lens group G3 or at least part of the fourth lens group G4 is especially preferably used as the focusing lens group GF. The focusing lens group GF may include a single cemented lens as in Examples described above. Alternatively, the number of lenses is not particularly limited, and one or more lens components, such as a single lens and a single cemented lens, may be used.
In the zoom optical system ZLI according to the 7th to the 10th embodiments, any of the lens group may be entirely or partially moved with a component in a direction orthogonal to the optical axis, or may be moved and rotated (swing) within an in-plane direction including the optical axis, to serve as the vibration-proof lens group for correcting image blur due to camera shake or the like. At least part of the fifth lens group G5 or at least part of the sixth lens group G6 is especially preferably used as the vibration-proof lens group.
In the zoom optical system ZLI according to the 7th to the 10th embodiments, the lens surface may be formed to have a spherical surface or a planer surface, or may be formed to have an aspherical shape. The lens surface having a spherical surface or a planer surface features easy lens processing and assembly adjustment, which leads to the processing and assembly adjustment less likely to involve an error compromising the optical performance, and thus is preferable. Furthermore, there is an advantage that a rendering performance is not largely compromised even when the image surface is displaced. The lens surface having an aspherical shape may be achieved with any one of an aspherical shape formed by grinding, a glass-molded aspherical shape obtained by molding a glass piece into an aspherical shape, and a composite type aspherical surface obtained by providing an aspherical shape resin piece on a glass surface. A lens surface may be a diffractive surface. The lens may be a gradient index lens (GRIN lens) or a plastic lens.
In the zoom optical system ZLI according to the 7th to the 10th embodiments, the aperture stop S is preferably disposed in the neighborhood of the third lens group G3. Alternatively, a lens frame may serve as the aperture stop so that the member serving as the aperture stop needs not to be provided.
In the zoom optical system ZLI according to the 7th to the 10th embodiments, the lens surfaces may be provided with an antireflection film featuring high transmittance over a wide range of wavelengths to achieve an excellent optical performance with reduced flare and ghosting and increased contract. The antireflection film may be selected as appropriate. Specifically, multilayer film coating or an antireflection film having an ultra low refractive index layer including minute crystal particle may be employed. The number of surfaces provided with the antireflection film is not particularly limited.
The zoom optical system ZLI according to the 7th to the 10th embodiment has a zooming rate of about 290 to 500%. The 35 mm equivalent focal length in the wide angle end state is about 22 to 30 mm, and Fno is about f/1.8 to 3.7 in the wide angle end state, and is about f/2.8 to 5.9 in the telephoto end state. However, these values should not be construed in a limiting sense.
Description of the Embodiments (11th to 14th Embodiments)
The 11th to 14th embodiments are described below with reference to drawings. A zoom optical system ZLII according to each of the embodiments includes the first lens group G1 having positive refractive power, a front-side lens group GX, an intermediate lens group GM having positive refractive power, and a rear-side lens group GR that are arranged in order from an object side; the front-side lens group GX is composed of one or more lens groups and has a negative lens group, at least part of the intermediate lens group GM is a focusing lens group GF, the rear-side lens group GR is composed of one or more lens groups, and upon zooming, the distance between the first lens group G1 and the front-side lens group GX is changed, the distance between the front-side lens group GX and the intermediate lens group GM is changed, and the distance between the intermediate lens group GM and the rear-side lens group GR is changed.
In the description of the 11th to the 14th embodiments below, the second lens group G2 is the front-side lens group GX. The third lens group G3 is the intermediate lens group GM at least partially including the focusing lens group GF. The third lens group G3 includes the object side group GA and the image side group GB that are arranged in order from the object side, and the image side group GB is the focusing lens group GF. The fourth lens group G4 is a lens group disposed closest to an object, in the rear-side lens group GR. The fifth lens group G5 is a lens group disposed second closest to an object, in the rear-side lens group GR.
The 11th embodiment is described below with reference to drawings. The zoom optical system ZLII according to the 11th embodiment includes, as illustrated in FIG. 21, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. The third lens group G3 includes the object side group GA and the image side group GB arranged in order from the object side. Upon focusing, the image side group GB (=the focusing lens group GF) is moved along the optical axis direction with the object side group GA fixed with respect to the image surface. Upon zooming, the fourth lens group G4 is moved with respect to the image surface.
With this configuration, the entire optical system can have a smaller size and simpler configuration. Furthermore, variation of image magnification can be reduced.
The zoom optical system ZLII according to the 11th embodiment satisfies the following conditional expressions (JK1) and (JK2) to achieve a higher optical performance.

0.50<|fF|/fM<5.00  (JK1)

0.51<(−fXn)/fM<1.60  (JK2)

where, fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB),
fM denotes a focal length of the intermediate lens group GM (the focal length of the third lens group G3), and
fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2).
The conditional expression (JK1) is for setting the focal length of the image side group GB as the focusing group and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than an upper limit value of the conditional expression (JK1) leads to low refractive power and thus a large movement amount of the focusing group upon focusing, rendering reduction of the minimum imaging distance difficult, or leads to excessively high refractive power of the third lens group G3 resulting in failure to successfully correct the spherical aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK1) is preferably set to be 4.50. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK1) is preferably set to be 4.30. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK1) is preferably set to be 4.00.
A value lower than a lower limit value of the conditional expression (JK1) leads to high refractive power of the focusing group resulting in failure to successfully correct the spherical aberration upon focusing on a short distant object, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK1) is preferably set to be 0.70. To more effectively guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK1) is preferably set to be 0.90. To more effectively guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK1) is preferably set to be 1.10.
The conditional expression (JK2) is for setting the focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2), and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than the upper limit value of the conditional expression (JK2) leads to low refractive power and thus a large movement amount of the second lens group G2 upon zooming, resulting in a large optical system and rendering correction of the curvature of field aberration difficult, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK2) is preferably set to be 1.55. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK2) is preferably set to be 1.50. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK2) is preferably set to be 1.45.
A value lower than a lower limit value of the conditional expression (JK2) results in failure to successfully correct variation of the spherical aberration and the curvature of field aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK2) is preferably set to be 0.53. To more effectively guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK2) is preferably set to be 0.55. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK2) is preferably set to be 0.57.
Preferably, the zoom optical system ZLII according to the 11th embodiment satisfies the following conditional expression (JK3).

0.01<dAB/|fF|<0.50  (JK3)

where, dAB denotes a distance between the focusing lens group GF and a lens disposed to the object side of the focusing lens group GF on the optical axis, upon focusing on infinity in the telephoto end state (the distance between the image side group GB and a lens closest to the image side group GB in a direction in which the image side group GB moves on the optical axis upon focusing from infinity to a short-distance object, upon focusing on infinity in the telephoto end state).
For example, in Example illustrated in FIG. 21, the distance dAB is a distance between a lens L34 closest to an object in the image side group GB and a lens L33 closest to an image in the object side group GA disposed to the object side of the image side group GB, on the optical axis, upon focusing on infinity in the telephoto end state.
The conditional expression (JK3) is for setting the focal length of the image side group GB as the focusing group and the distance between the focusing group and the lens disposed to the object side of the focusing group upon focusing from infinity to a short-distance object. A value higher than an upper limit value of the conditional expression (JK3) leads to high refractive power of the focusing group resulting in failure to successfully correct the variation of spherical aberration upon focusing, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK3) is preferably set to be 0.46. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK3) is preferably set to be 0.42. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK3) is preferably set to be 0.38.
A value lower than a lower limit value of the conditional expression (JK3) leads to excessively low refractive power and thus a large movement amount of the image side group GB as the focusing group upon focusing on a short distant object, resulting in a large entire lens and failure to successfully correct the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK3) is preferably set to be 0.02. To more effectively guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK3) is preferably set to be 0.03. To more effectively guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK3) is preferably set to be 0.04.
Preferably, in the zoom optical system ZLII according to the 11th embodiment, the first lens group G1 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and a spherical aberration can be successfully corrected in the telephoto end state.
Preferably, in the zoom optical system ZLII according to the 11th embodiment, the second lens group G2 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field occurring upon zooming can be reduced.
Preferably, in the zoom optical system ZLII according to the 11th embodiment, the third lens group G3 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field aberration occurring upon zooming can be reduced.
Preferably, in the zoom optical system ZLII according to the 11th embodiment, the fourth lens group G4 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field aberration occurring upon zooming can be reduced.
Preferably, in the zoom optical system ZLII according to the 11th embodiment, the focusing lens group (the image side group GB forming the third lens group G3) includes a positive lens when having positive refractive power as a whole, and the following conditional expressions (JK4) and (JK5) are satisfied.

ndp+0.0075×υdp−2.175<0  (JK4)

υυdp>50.00  (JK5)

where, ndp denotes a refractive index of the medium as the positive lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdp denotes Abbe number based on the d-line of the medium as the positive lens in the focusing lens group GF (image side group GB).
The conditional expression (JK4) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JK4) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK4) is preferably set to be −0.015. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK4) is preferably set to be −0.030. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK4) is preferably set to be −0.045.
The conditional expression (JK5) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JK5) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a negative lens, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK5) is preferably set to be 52.00. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK5) is preferably set to be 54.00. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK5) is preferably set to be 55.00.
Preferably, in the zoom optical system ZLII according to the 11th embodiment, the focusing lens group (the image side group GB forming the third lens group G3) includes a negative lens when having negative refractive power as a whole, and the following conditional expressions (JK6) and (JK7) are satisfied.

ndn+0.0075×υdn−2.175<0  (JK6)

υdn>50.00  (JK7)

where ndn denotes a refractive index of the medium as the negative lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdn denotes Abbe number based on the d-line of the medium as the negative lens in the focusing lens group GF (image side group GB).
The conditional expression (JK6) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JK6) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK6) is preferably set to be −0.015. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK6) is preferably set to be −0.030. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK6) is preferably set to be −0.045.
The conditional expression (JK7) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JK7) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a positive lens, and thus is unfavorable.
To guarantee the effects of the 11th embodiment, the lower limit value of the conditional expression (JK7) is preferably set to be 52.00. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK7) is preferably set to be 54.00. To more effectively guarantee the effects of the 11th embodiment, the upper limit value of the conditional expression (JK7) is preferably set to be 55.00.
The zoom optical system ZLII according to the 11th embodiment preferably includes the vibration-proof lens group VR that is disposed between the image side group GB and the lens disposed closest to an image in the optical system, and can move with a displacement component in the direction orthogonal to the optical axis to correct image blur. For example, in Example illustrated in FIG. 21, the vibration-proof lens group VR is the fourth lens group G4 disposed between the image side group GB and the lens disposed closest to an image in the optical system.
With this configuration, the decentering coma aberration of the vibration-proof lens group VR and astigmatism can be successfully corrected with small variation of image magnification upon focusing.
As described above, the 11th embodiment can achieve the zoom optical system ZLII featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) including the above-described zoom optical system ZLII described above will be described with reference to FIG. 46. As illustrated in FIG. 46, this camera 11 is a lens interchangeable camera (what is known as a mirrorless camera) including the above described zoom optical system ZLII as an imaging lens 12. In the camera 11, light from an unillustrated object (subject) is collected by the imaging lens 12 and passes through an unillustrated Optical low pass filter (OLPF) to be a subject image formed on an imaging plane of an imaging unit 13. Then, the subject image is photoelectrically converted into an image of the subject by a photoelectric conversion element on the imaging unit 13. The image is displayed on an Electronic view finder (EVF) 14 provided to the camera 11. Thus, a photographer can monitor the subject through the EVF 14. When the photographer presses an unillustrated release button, the image of the subject generated by the imaging unit 13 is stored in an unillustrated memory. In this manner, the photographer can capture an image of a subject with the camera 11.
The zoom optical system ZLII according to the 11th embodiment, installed in the camera 11 as the imaging lens 12, features a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 11.
The 11th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 11 can be obtained with the above-described zoom optical system ZLII installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLII will be described with reference to FIG. 47. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST1110). The third lens group G3 includes the object side group GA and the image side group GB arranged in order from the object side, and the lenses are arranged in such a manner that the image side group GB (=the focusing lens group GF) moves along the optical axis direction upon focusing (step ST1120). The lenses are arranged in such a manner that the fourth lens group G4 is moved with respect to the image surface upon zooming (step ST1130). The lenses are arranged in the barrel to satisfy the following conditional expressions (JK1) and (JK2) (step ST1140).

0.50<|fF|/fM<5.00  (JK1)

0.51<(−fXn)/fM<1.60  (JK2)

where, fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB),
fM denotes a focal length of the intermediate lens group GM (the focal length of the third lens group G3), and
fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2).
In one example of the lens arrangement according to the 11th embodiment, as illustrated in FIG. 21, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the object side group GA including the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side, and the image side group GB including a cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side, the fourth lens group G4 including the cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42, and the fifth lens group G5 including the biconvex lens L51, a cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLII is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 11th embodiment, the zoom optical system ZLII featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 12th embodiment is described below with reference to drawings. The zoom optical system ZLII according to the 12th embodiment includes, as illustrated in FIG. 21, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. The third lens group G3 includes the object side group GA and the image side group GB arranged in order from the object side. Upon focusing, the image side group GB (=the focusing lens group GF) is moved along the optical axis direction with the object side group GA fixed with respect to the image surface. Upon zooming, the first lens group G1 is moved toward the object side with respect to the image surface, and the second lens group G2 is moved with respect to the image surface.
With this configuration, the entire optical system can have a smaller size and simpler configuration. Furthermore, variation of image magnification can be reduced.
To achieve an even higher optical performance, the zoom optical system ZLII according to the 12th embodiment includes an air lens, formed between the image side group GB and an adjacent lens group and positioned on a side on which the image side group GB is moved upon focusing from infinity to a short-distance object, satisfies the following conditional expression (JL1).
For example, in Example illustrated in FIG. 21, the air lens is an air lens that includes a 20th surface and a 21st surface and is formed between the image side group GB and an adjacent lens group (the object side group GA in this example) and positioned on a side on which the image side group GB is moved upon zooming from infinity to a short-distance object.

1.50<|(rB+rA)/(rB−rA)|  (JL1)

where, rA denotes a radius of curvature of an object side lens surface of the air lens, and
rB denotes a radius of curvature of an image side lens surface of the air lens.
The conditional expression (JL1) is for setting a shape of the air lens formed between the image side group GB as the focusing group and an adjacent lens group. A value lower than a lower limit value of the conditional expression (JL1) leads to high refractive power of the air lens resulting in failure to successfully correct the spherical aberration and the curvature of field aberration upon focusing on a short distant object, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL1) is preferably set to be 2.10. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL1) is preferably set to be 2.70. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL1) is preferably set to be 3.30.
Preferably, the zoom optical system ZLII according to the 12th embodiment satisfies the following conditional expression (JL2).

0.50<|fF|/fM<5.00  (JL2)

where, fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB), and
fM denotes a focal length of the intermediate lens group GM (the focal length of the third lens group G3).
The conditional expression (JL2) is for setting the focal length of the image side group GB as the focusing group and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than an upper limit value of the conditional expression (JL2) leads to low refractive power and thus a large movement amount of the focusing group upon focusing, rendering reduction of the minimum imaging distance difficult, or leads to excessively high refractive power of the third lens group G3 resulting in failure to successfully correct the spherical aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL2) is preferably set to be 4.15. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL2) is preferably set to be 3.35. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL2) is preferably set to be 2.55.
A value lower than a lower limit value of the conditional expression (JL2) leads to high refractive power of the focusing group resulting in failure to successfully correct the spherical aberration upon focusing on a short distant object, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL2) is preferably set to be 0.70. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL2) is preferably set to be 0.90. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL2) is preferably set to be 1.10.
Preferably, the zoom optical system ZLII according to the 12th embodiment satisfies the following conditional expression (JL3).

0.01<dAB/|fF|<0.50  (JL3)

where, dAB denotes a distance between the focusing lens group GF and a lens disposed to the object side of the focusing lens group GF upon focusing on infinity in the telephoto end state on the optical axis (the distance between the image side group GB and a lens closest to the image side group GB in a direction in which the image side group GB moves on the optical axis upon focusing from infinity to a short-distance object, upon focusing on infinity in the telephoto end state), and
fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB).
For example, in Example illustrated in FIG. 21, the distance dAB is a distance between the lens L34 closest to an object in the image side group GB and the lens L33 closest to an image in the object side group GA disposed to the object side of the image side group GB, on the optical axis, upon focusing on infinity in the telephoto end state.
The conditional expression (JL3) is for setting the focal length of the image side group GB as the focusing group and the distance between the focusing group and the lens disposed to the object side of the focusing group upon focusing from infinity to a short-distance object. A value higher than an upper limit value of the conditional expression (JL3) leads to high refractive power of the focusing group resulting in failure to successfully correct the variation of spherical aberration upon focusing, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL3) is preferably set to be 0.46. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL3) is preferably set to be 0.42. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL3) is preferably set to be 0.38.
A value lower than a lower limit value of the conditional expression (JL3) leads to excessively low refractive power and thus a large movement amount of the image side group GB as the focusing group upon focusing on a short distant object, resulting in a large entire lens and failure to successfully correct the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL3) is preferably set to be 0.02. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL3) is preferably set to be 0.03. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL3) is preferably set to be 0.04.
Preferably, in the zoom optical system ZLII according to the 12th embodiment, the firth lens group G1 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and spherical aberration can be successfully corrected in the telephoto end state.
Preferably, in the zoom optical system ZLII according to the 12th embodiment, the second lens group G2 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field occurring upon zooming can be reduced.
Preferably, in the zoom optical system ZLII according to the 12th embodiment, the fourth lens group G4 and all the lens groups disposed to the image side of the fourth lens group G4 or at least the fourth lens group G4 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field aberration occurring upon zooming can be reduced.
Preferably, the zoom optical system ZLII according to the 12th embodiment satisfies the following conditional expression (JL4).

0.20<(−fXn)/fM<1.60  (JL4)

where, fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2).
The conditional expression (JL4) is for setting the focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2), and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than the upper limit value of the conditional expression (JL4) leads to low refractive power and thus a large movement amount of the second lens group G2 upon zooming, resulting in a large optical system and rendering correction of the curvature of field aberration difficult, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL4) is preferably set to be 1.55. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL4) is preferably set to be 1.50. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL4) is preferably set to be 1.45. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL4) is preferably set to be 1.20.
A value lower than a lower limit value of the conditional expression (JL4) results in failure to successfully correct variation of the spherical aberration and the curvature of field aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL4) is preferably set to be 0.25. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL4) is preferably set to be 0.30. To more effectively guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL4) is preferably set to be 0.35.
Preferably, in the zoom optical system ZLII according to the 12th embodiment, the focusing lens group GF (the image side group GB) includes a positive lens when having positive refractive power as a whole, and the following conditional expressions (JL5) and (JL6) are satisfied.

ndp+0.0075×υdp−2.175<0  (JL5)

υdp>50.00  (JL6)

where, ndp denotes a refractive index of the medium as the positive lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdp denotes Abbe number based on the d-line of the medium as the positive lens in the focusing lens group GF (image side group GB).
The conditional expression (JL5) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JL5) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL5) is preferably set to be −0.015. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL5) is preferably set to be −0.030. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL5) is preferably set to be −0.045.
The conditional expression (JL6) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JL6) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a negative lens, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL6) is preferably set to be 52.00. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL6) is preferably set to be 54.00. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL6) is preferably set to be 55.00.
Preferably, in the zoom optical system ZLII according to the 12th embodiment, the focusing lens group GF (the image side group GB) includes a negative lens when having negative refractive power as a whole, and the following conditional expressions (JL7) and (JL8) are satisfied.

ndn+0.0075×υdn−2.175<0  (JL7)

υdn>50.00  (JL8)

where, ndn denotes a refractive index of the medium as the negative lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdn denotes Abbe number based on the d-line of the medium as the negative lens in the focusing lens group GF (image side group GB).
The conditional expression (JL7) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JL7) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL7) is preferably set to be −0.015. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL7) is preferably set to be −0.030. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL7) is preferably set to be −0.045.
The conditional expression (JL8) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JL8) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a positive lens, and thus is unfavorable.
To guarantee the effects of the 12th embodiment, the lower limit value of the conditional expression (JL8) is preferably set to be 52.00. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL8) is preferably set to be 54.00. To more effectively guarantee the effects of the 12th embodiment, the upper limit value of the conditional expression (JL8) is preferably set to be 55.00.
The zoom optical system ZLII according to the 12th embodiment preferably includes the vibration-proof lens group VR that is disposed between the image side group GB and the lens disposed closest to an image in the optical system, and can move with a displacement component in the direction orthogonal to the optical axis to correct image blur. For example, in Example illustrated in FIG. 21, the vibration-proof lens group VR is the fourth lens group G4 disposed between the image side group GB and the lens disposed closest to an image in the optical system.
With this configuration, the decentering coma aberration of the vibration-proof lens group VR and astigmatism can be successfully corrected with small variation of image magnification upon focusing.
As described above, the 12th embodiment can achieve the zoom optical system ZLII featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Next, a camera (optical device) 11 including the above-described zoom optical system ZLII described above will be described with reference to FIG. 46. This camera 11 is the same as that in the 11th embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLII according to the 12th embodiment, installed in the camera 11 as the imaging lens 12, featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be achieved with the camera 11.
The 12th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 11 can be obtained with the above-described zoom optical system ZLII installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLII will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST1210). The third lens group G3 includes the object side group GA and the image side group GB arranged in order from the object side, and the lenses are arranged in such a manner that the image side group GB (=the focusing lens group GF) moves along the optical axis direction upon focusing (step ST1220). The lenses are arranged in such a manner that the first lens group G1 moves toward the object side with respect to the image surface and the second lens group G2 is moved with respect to the image surface upon zooming (step ST1230). The lenses are arranged in such a manner that an air lens, formed between the image side group GB and an adjacent lens group and positioned in direction in which the image side group GB is moved upon focusing from infinity to a short-distance object, satisfies the following conditional expression (JL1) (step ST1240).

1.50<|(rB+rA)/(rB−rA)|  (JL1)

where, rA denotes a radius of curvature of an object side lens surface of the air lens, and
rB denotes a radius of curvature of an image side lens surface of the air lens.
In one example of the lens arrangement according to the 12th embodiment, as illustrated in FIG. 21, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the object side group GA including the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side, and the image side group GB including the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side, the fourth lens group G4 including the cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42, and the fifth lens group G5 including the biconvex lens L51, the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLII is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 12th embodiment, the zoom optical system featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance can be manufactured.
The 13th embodiment is described below with reference to drawings. The zoom optical system ZLII according to the 13th embodiment includes, as illustrated in FIG. 21, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. The third lens group G3 includes the object side group GA and the image side group GB arranged in order from the object side. Upon focusing, the image side group GB (=the focusing lens group GF) is moved along the optical axis direction with the object side group GA fixed with respect to the image surface.
With this configuration, the entire optical system can have a smaller size and simpler configuration.
The zoom optical system ZLII according to the 13th embodiment includes the vibration-proof lens group VR that is disposed between the image side group GB and the lens disposed closest to an image in the optical system, and can move with a displacement component in the direction orthogonal to the optical axis to correct image blur.
For example, in Example illustrated in FIG. 21, the vibration-proof lens group VR is the fourth lens group G4 disposed between the image side group GB and the lens disposed closest to an image in the optical system.
With this configuration, the decentering coma aberration of the vibration-proof lens group VR and astigmatism can be successfully corrected with small variation of image magnification upon focusing.
The zoom optical system ZLII according to the 13th embodiment satisfies the following conditional expressions (JM1) and (JM2) to achieve a higher optical performance.

0.01<dV/|fV|<0.50  (JM1)

0.50<|fF|/fM<3.00  (JM2)

where, dV denotes a distance between the vibration-proof lens group VR and a lens disposed to the image side thereof in the telephoto end state on the optical axis,
fV denotes a focal length of the vibration-proof lens group VR,
fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB), and
fM denotes a focal length of the intermediate lens group GM (the focal length of the third lens group G3).
The conditional expression (JM1) is for setting the distance of what is known as an air lens formed between the vibration-proof lens group VR and a lens disposed to the image side thereof that area separated from each other with a distance in between. A value higher than an upper limit value of the conditional expression (JM1) leads to an excessive large distance of the air lens, resulting in failure to successfully correct the decentering coma aberration and the curvature of field aberration upon image blur correction, or leads to excessively high refractive power of the vibration-proof lens group VR resulting in failure to successfully correct the decentering coma aberration and the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM1) is preferably set to be 0.47. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM1) is preferably set to be 0.44. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM1) is preferably set to be 0.42.
A value lower than a lower limit value of the conditional expression (JM1) leads to no distance of the air lens, resulting in collision between the vibration-proof lens group VR and a lens disposed to the image side thereof, or leads to an excessively long focal length, that is, a large movement amount of the vibration-proof lens group VR, rendering the control difficult or resulting in a failure to successfully correct the decentering coma aberration when the vibration-proof lens is decentered and the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM1) is preferably set to be 0.015. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM1) is preferably set to be 0.016.
The conditional expression (JM2) is for setting the focal length of the image side group GB as the focusing group and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than an upper limit value of the conditional expression (JM2) leads to low refractive power and thus a large movement amount of the focusing group upon focusing, rendering reduction of the minimum imaging distance difficult, or leads to excessively high refractive power of the third lens group G3 resulting in failure to successfully correct the spherical aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM2) is preferably set to be 2.90. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM2) is preferably set to be 2.80. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM2) is preferably set to be 2.75.
A value lower than a lower limit value of the conditional expression (JM2) leads to high refractive power of the focusing group resulting in failure to successfully correct the spherical aberration upon focusing on a short distant object, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM2) is preferably set to be 0.70. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM2) is preferably set to be 0.90. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM2) is preferably set to be 1.10.
Preferably, the zoom optical system ZLII according to the 13th embodiment satisfies the following conditional expression (JM3).

0.01<dAB/|fF|<0.50  (JM3)

where, dAB denotes a distance between the focusing lens group GF and a lens disposed to the object side of the focusing lens group GF upon focusing on infinity in the telephoto end state on the optical axis (the distance between the image side group GB and a lens closest to the image side group GB in a direction in which the image side group GB moves on the optical axis upon focusing from infinity to a short-distance object, upon focusing on infinity in the telephoto end state).
For example, in Example illustrated in FIG. 21, the distance dAB is a distance between the lens L34 closest to an object in the image side group GB and the lens L33 closest to an image in the object side group GA disposed to the object side of the image side group GB, on the optical axis, upon focusing on infinity in the telephoto end state.
The conditional expression (JM3) is for setting the focal length of the image side group GB as the focusing group and the distance between the focusing group and the lens disposed to the object side of the focusing group upon focusing from infinity to a short-distance object. A value higher than an upper limit value of the conditional expression (JM3) leads to high refractive power of the focusing group resulting in failure to successfully correct the variation of spherical aberration upon focusing, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM3) is preferably set to be 0.46. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM3) is preferably set to be 0.42. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM3) is preferably set to be 0.38.
A value lower than a lower limit value of the conditional expression (JM3) leads to excessively low refractive power and thus a large movement amount of the image side group GB as the focusing group upon focusing on a short distant object, resulting in a large entire lens and failure to successfully correct the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM3) is preferably set to be 0.02. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM3) is preferably set to be 0.03. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM3) is preferably set to be 0.04.
Preferably, in the zoom optical system ZLII according to the 13th embodiment, the first lens group G1 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and spherical aberration can be successfully corrected in the telephoto end state.
Preferably, in the zoom optical system ZLII according to the 13th embodiment, the second lens group G2 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field occurring upon zooming can be reduced.
Preferably, in the zoom optical system ZLII according to the 13th embodiment, the fourth lens group G4 and all the lens group disposed to the image side thereof or at least the fourth lens group G4 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field aberration occurring upon zooming can be reduced.
Preferably, the zoom optical system ZLII according to the 13th embodiment satisfies the following conditional expression (JM4).

0.20<(−fXn)/fM<1.60  (JM4)

where, fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2).
The conditional expression (JM4) is for setting the focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2), and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than the upper limit value of the conditional expression (JM4) leads to low refractive power and thus a large movement amount of the second lens group G2 upon zooming, resulting in a large optical system and rendering correction of the curvature of field aberration difficult, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM4) is preferably set to be 1.55. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM4) is preferably set to be 1.50. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM4) is preferably set to be 1.45. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM4) is preferably set to be 1.20.
A value lower than a lower limit value of the conditional expression (JM4) results in failure to successfully correct variation of the spherical aberration and the curvature of field aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM4) is preferably set to be 0.25. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM4) is preferably set to be 0.30. To more effectively guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM4) is preferably set to be 0.35.
Preferably, in the zoom optical system ZLII according to the 13th embodiment, the focusing lens group GF (the image side group GB) includes a positive lens when having positive refractive power as a whole, and the following conditional expressions (JM5) and (JM6) are satisfied.

ndp+0.0075×υdp−2.175<0  (JM5)

υdp>50.00  (JM6)

where, ndp denotes a refractive index of the medium as the positive lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdp denotes Abbe number based on the d-line of the medium as the positive lens in the focusing lens group GF (image side group GB).
The conditional expression (JM5) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JM5) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM5) is preferably set to be −0.015. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM5) is preferably set to be −0.030. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM5) is preferably set to be −0.045.
The conditional expression (JM6) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JM6) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a negative lens, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM6) is preferably set to be 52.00. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM6) is preferably set to be 54.00. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM6) is preferably set to be 55.00.
Preferably, in the zoom optical system ZLII according to the 13th embodiment, the focusing lens group GF (the image side group GB) includes a negative lens when having negative refractive power as a whole, and the following conditional expressions (JM7) and (JM8) are satisfied.

ndn+0.0075×υdn−2.175<0  (JM7)

υdn>50.00  (JM8)

where, ndn denotes a refractive index of the medium as the negative lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdn denotes Abbe number based on the d-line of the medium as the negative lens in the focusing lens group GF (image side group GB).
The conditional expression (JM7) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JM7) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM7) is preferably set to be −0.015. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM7) is preferably set to be −0.030. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM7) is preferably set to be −0.045.
The conditional expression (JM8) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JM8) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a positive lens, and thus is unfavorable.
To guarantee the effects of the 13th embodiment, the lower limit value of the conditional expression (JM8) is preferably set to be 52.00. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM8) is preferably set to be 54.00. To more effectively guarantee the effects of the 13th embodiment, the upper limit value of the conditional expression (JM8) is preferably set to be 55.00.
As described above, the 13th embodiment can achieve the zoom optical system ZLII featuring a small size and an excellent optical performance.
Next, a camera (optical device) 11 including the above-described zoom optical system ZLII described above will be described with reference to FIG. 46. This camera 11 is the same as that in the 11th embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLII according to the 13th embodiment, installed in the camera 11 as the imaging lens 12, featuring a small size and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size and an excellent optical performance can be achieved with the camera 11.
The 13th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 11 can be obtained with the above-described zoom optical system ZLII installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLII will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 are arranged in a barrel in order from the object side along the optical axis and that the zooming is performed with the distance between the lens groups changed (step ST1310). The third lens group G3 includes the object side group GA and the image group GB arranged in order from the object side, and the lenses are arranged in such a manner that the image side group GB (=the focusing lens group GF) moves along the optical axis direction upon focusing (step ST1320). The lenses are arranged in such a manner that the vibration-proof lens group VR configured to be movable with a displacement component in a direction orthogonal to the optical axis to correct image blur is disposed between the image side group GB and the lens closest to the image in the optical system (step ST1330). The lenses are arranged to satisfy the following conditional expressions (JM1) and (JM2) (step S1340).

0.01<dV/|fV|<0.50  (JM1)

0.50<|fF|/fM<3.00  (JM2)

where, dV denotes a distance between the vibration-proof lens group VR and a lens disposed to the image side thereof in the telephoto end state on the optical axis,
fV denotes a focal length of the vibration-proof lens group VR,
fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB), and
fM denotes a focal length of the intermediate lens group GM (the focal length of the third lens group G3).
In one example of the lens arrangement according to the 13th embodiment, as illustrated in FIG. 21, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the object side group GA including the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side, and the image side group GB including the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side, the fourth lens group G4 including the cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42, and the fifth lens group G5 including the biconvex lens L51, the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLII is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 13th embodiment, the zoom optical system featuring a small size and an excellent optical performance can be manufactured.
The 14th embodiment is described below with reference to drawings. The zoom optical system ZLII according to the 14th embodiment includes, as illustrated in FIG. 21, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4, and the fifth lens group G5 that are arranged in order from the object side, and performs zooming by changing a distance between the lens groups. The third lens group G3 includes the object side group GA and the image side group GB arranged in order from the object side. Upon focusing, the image side group GB (=the focusing lens group GF) is moved along the optical axis direction with the object side group GA fixed with respect to the image surface. Upon zooming, the second lens group G2 is moved with respect to the image surface.
With this configuration, the entire optical system can have a smaller size and simpler configuration. Furthermore, variation of image magnification can be reduced.
The zoom optical system ZLII according to the 14th embodiment satisfies the following conditional expression (JN1) to achieve a higher optical performance.

0.50<|fF|/fM<5.00  (JN1)

where, fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB), and
fM denotes a focal length of the intermediate lens group GM (the focal length of the third lens group G3).
The conditional expression (JN1) is for setting the focal length of the image side group GB as the focusing group and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than an upper limit value of the conditional expression (JN1) leads to low refractive power and thus a large movement amount of the focusing group upon focusing, rendering reduction of the minimum imaging distance difficult, or leads to excessively high refractive power of the third lens group G3 resulting in failure to successfully correct the spherical aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN1) is preferably set to be 4.50. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN1) is preferably set to be 4.30. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN1) is preferably set to be 4.00.
A value lower than a lower limit value of the conditional expression (JN1) leads to high refractive power of the focusing group resulting in failure to successfully correct the spherical aberration upon focusing on a short distant object, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN1) is preferably set to be 0.70. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN1) is preferably set to be 0.90. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN1) is preferably set to be 1.10.
The zoom optical system ZLII according to the 14th embodiment preferably includes the vibration-proof lens group VR that is disposed between the image side group GB and the lens disposed closest to an image in the optical system, and can move with a displacement component in the direction orthogonal to the optical axis to correct image blur.
For example, in Example illustrated in FIG. 21, the vibration-proof lens group VR is the fourth lens group G4 disposed between the image side group GB and the lens disposed closest to an image in the optical system.
With this configuration, the decentering coma aberration of the vibration-proof lens group VR and astigmatism can be successfully corrected with small variation of image magnification upon focusing.
Preferably, the zoom optical system ZLII according to the 14th embodiment satisfies the following conditional expression (JN2).

0.01<dV/|fV|<0.50  (JN2)

where, dV denotes a distance between the vibration-proof lens group VR and a lens disposed to the image side thereof in the telephoto end state on the optical axis, and
fV denotes a focal length of the vibration-proof lens group VR.
The conditional expression (JN2) is for setting the distance of what is known as an air lens formed between the vibration-proof lens group VR and a lens disposed to the image side thereof that area separated from each other with a distance in between. A value higher than an upper limit value of the conditional expression (JN2) leads to an excessive large distance of the air lens, resulting in failure to successfully correct the decentering coma aberration and the curvature of field aberration upon image blur correction, or leads to excessively high refractive power of the vibration-proof lens group VR resulting in failure to successfully correct the decentering coma aberration and the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN2) is preferably set to be 0.47. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN2) is preferably set to be 0.44. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN2) is preferably set to be 0.42.
A value lower than a lower limit value of the conditional expression (JN2) leads to no distance of the air lens, resulting in collision between the vibration-proof lens group VR and a lens disposed to the image side thereof, or leads to an excessively long focal length, that is, a large movement amount of the vibration-proof lens group VR, rendering the control difficult or resulting in a failure to successfully correct the decentering coma aberration when the vibration-proof lens is decentered and the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN2) is preferably set to be 0.015. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN2) is preferably set to be 0.016.
Preferably, the zoom optical system ZLII according to the 14th embodiment satisfies the following conditional expression (JN3).

0.01<dAB/|fF|<0.50  (JN3)

where, dAB denotes a distance between the focusing lens group GF and a lens disposed to the object side of the focusing lens group GF upon focusing on infinity in the telephoto end state on the optical axis (the distance between the image side group GB and a lens closest to the image side group GB in a direction in which the image side group GB moves on the optical axis upon focusing from infinity to a short-distance object, upon focusing on infinity in the telephoto end state).
For example, in Example illustrated in FIG. 21, the distance dAB is a distance between the lens L34 closest to an object in the image side group GB and the lens L33 closest to an image in the object side group GA disposed to the object side of the image side group GB, on the optical axis, upon focusing on infinity in the telephoto end state.
The conditional expression (JN3) is for setting the focal length of the image side group GB as the focusing group and the distance between the focusing group and the lens disposed to the object side of the focusing group upon focusing from infinity to a short-distance object. A value higher than an upper limit value of the conditional expression (JN3) leads to high refractive power of the focusing group resulting in failure to successfully correct the variation of spherical aberration upon focusing, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN3) is preferably set to be 0.46. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN3) is preferably set to be 0.42. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN3) is preferably set to be 0.38.
A value lower than a lower limit value of the conditional expression (JN3) leads to excessively low refractive power and thus a large movement amount of the image side group GB as the focusing group upon focusing on a short distant object, resulting in a large entire lens and failure to successfully correct the curvature of field aberration, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN3) is preferably set to be 0.02. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN3) is preferably set to be 0.03. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN3) is preferably set to be 0.04.
Preferably, in the zoom optical system ZLII according to the 14th embodiment, the first lens group G1 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and spherical aberration can be successfully corrected in the telephoto end state.
Preferably, in the zoom optical system ZLII according to the 14th embodiment, the second lens group G2 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a spherical aberration and a curvature of field occurring upon zooming can be reduced.
Preferably, in the zoom optical system ZLII according to the 14th embodiment, the fifth lens group G5 and all the lens group disposed to the image side thereof or at least the fifth lens group G5 is moved with respect to the image surface upon zooming. With this configuration, effective zooming can be achieved, and variation of a curvature of field aberration occurring upon zooming can be reduced.
Preferably, the zoom optical system ZLII according to the 14th embodiment satisfies the following conditional expression (JN4).

0.20<(−fXn)/fM<1.60  (JN4)

where, fXn denotes a focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2).
The conditional expression (JN4) is for setting the focal length of a lens group with the largest absolute value of refractive power in a negative lens group of the front-side lens group GX (the focal length of the second lens group G2), and the focal length of the intermediate lens group GM (the focal length of the third lens group G3). A value higher than the upper limit value of the conditional expression (JN4) leads to low refractive power and thus a large movement amount of the second lens group G2 upon zooming, resulting in a large optical system and rendering correction of the curvature of field aberration difficult, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN4) is preferably set to be 1.55. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN4) is preferably set to be 1.50. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN4) is preferably set to be 1.45. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN4) is preferably set to be 1.20.
A value lower than a lower limit value of the conditional expression (JN4) results in failure to successfully correct variation of the spherical aberration and the curvature of field aberration upon zooming, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN4) is preferably set to be 0.25. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN4) is preferably set to be 0.30. To more effectively guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN4) is preferably set to be 0.35.
Preferably, in the zoom optical system ZLII according to the 14th embodiment, the focusing lens group GF (the image side group GB) includes a positive lens when having positive refractive power as a whole, and the following conditional expressions (JN5) and (JN6) are satisfied.

ndp+0.0075×υdp−2.175<0  (JN5)

υdp>50.00  (JN6)

where, ndp denotes a refractive index of the medium as the positive lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdp denotes Abbe number based on the d-line of the medium as the positive lens in the focusing lens group GF (image side group GB).
The conditional expression (JN5) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JN5) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN5) is preferably set to be −0.015. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN5) is preferably set to be −0.030. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN5) is preferably set to be −0.045.
The conditional expression (JN6) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JN6) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a negative lens, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN6) is preferably set to be 52.00. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN6) is preferably set to be 54.00. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN6) is preferably set to be 55.00.
Preferably, in the zoom optical system ZLII according to the 14th embodiment, the focusing lens group GF (the image side group GB) includes a negative lens when having negative refractive power as a whole, and the following conditional expressions (JN7) and (JN8) are satisfied.

ndn+0.0075×υdn−2.175<0  (JN7)

υdn>50.00  (JN8)

where, ndn denotes a refractive index of the medium as the negative lens in the focusing lens group GF (image side group GB) with respect to the d-line, and
υdn denotes Abbe number based on the d-line of the medium as the negative lens in the focusing lens group GF (image side group GB).
The conditional expression (JN7) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value higher than an upper limit value of the conditional expression (JN7) leads to excessively high refractive power with respect to a glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN7) is preferably set to be −0.015. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN7) is preferably set to be −0.030. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN7) is preferably set to be −0.045.
The conditional expression (JN8) is for setting a glass material of a lens used in the image side group GB as the focusing group. A value lower than a lower limit value of the conditional expression (JN8) leads to a large glass's dispersion, rendering correction of a chromatic aberration upon focusing on a short distant object difficult even when the lens is cemented with a positive lens, and thus is unfavorable.
To guarantee the effects of the 14th embodiment, the lower limit value of the conditional expression (JN8) is preferably set to be 52.00. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN8) is preferably set to be 54.00. To more effectively guarantee the effects of the 14th embodiment, the upper limit value of the conditional expression (JN8) is preferably set to be 55.00.
As described above, the 14th embodiment can achieve the zoom optical system ZLII featuring a small size and an excellent optical performance.
Next, a camera (optical device) 11 including the above-described zoom optical system ZLII described above will be described with reference to FIG. 46. This camera 11 is the same as that in the 11th embodiment the configuration of which has been described above, and thus will not be described herein.
The zoom optical system ZLII according to the 14th embodiment, installed in the camera 11 as the imaging lens 12, featuring a small size and an excellent optical performance, due to its characteristic lens configuration as can be seen in Examples described later. Thus, an optical device featuring a small size and an excellent optical performance can be achieved with the camera 11.
The 14th embodiment is described with the mirrorless camera as an example, but this should not be construed in a limiting sense. For example, similar or the same effects as the camera 11 can be obtained with the above-described zoom optical system ZLII installed in a single lens reflex camera in which a quick return mirror is provided to a camera main body and a subject is monitored with a view finder optical system.
Next, a method for manufacturing the above-described zoom optical system ZLII will be described. First of all, lenses are arranged in such a manner that the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4, and the fifth lens group G5 are arranged in a barrel in order from the object side and that the zooming is performed with the distance between the lens groups changed (step ST1410). The third lens group G3 includes the object side group GA and the image side group GB arranged in order from the object side, and the lenses are arranged in such a manner that the image side group GB (=the focusing lens group GF) moves along the optical axis direction upon focusing (step ST1420). The lenses are arranged in such a manner that the second lens group G2 is moved with respect to the image surface upon zooming (step ST1430). The lenses are arranged in the barrel to satisfy the following conditional expression (JN1) (step S1440).

0.50<|fF|/fM<5.00  (JN1)

where, fF denotes a focal length of the focusing lens group GF (the focal length of the image side group GB), and
fM denotes a focal length of the intermediate lens group GM (the focal length of the third lens group G3).
In one example of the lens arrangement according to the 14th embodiment, as illustrated in FIG. 21, the first lens group G1 including the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12, and the positive meniscus lens L13 having a convex surface facing the object side, the second lens group G2 including the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side, the third lens group G3 including the object side group GA including the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side, and the image side group GB including the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side, the fourth lens group G4 including the cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42, and the fifth lens group G5 including the biconvex lens L51, the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side, and the negative meniscus lens L54 having a concave surface facing the object side are arranged in order from the object side. The zoom optical system ZLII is manufactured with the lens groups thus arranged through the procedure described above.
With the manufacturing method according to the 14th embodiment, the zoom optical system ZLII featuring a small size and an excellent optical performance can be manufactured.
Examples According to 11th to 14th Embodiments
Examples according to the 11th to the 14th embodiments are described with reference to the drawings. Table 15 to Table 39 described below are specification tables of Examples 15 to 39.
The 11th embodiment corresponds to Examples 15 to 38, and the like.
The 12th embodiment corresponds to Examples 15, 17 to 21, 23, 24, 27 to 29, 36, and 39 and the like.
The 13th embodiment corresponds to Examples 15 to 24, 26 to 36, 38, and 39 and the like.
The 14th embodiment corresponds to Examples 15 to 18, 20 to 23, 25 to 30, and 32 to 39 and the like.
FIG. 21, FIG. 22, FIG. 23, FIG. 24, FIG. 25, FIG. 26, FIG. 27, FIG. 28, FIG. 29, FIG. 30, FIG. 31, FIG. 32, FIG. 33, FIG. 34, FIG. 35, FIG. 36, FIG. 37, FIG. 38, FIG. 39, FIG. 40, FIG. 41, FIG. 42, FIG. 43, FIG. 44, and FIG. 45 are cross-sectional views illustrating configurations and refractive power distributions of the zoom optical systems ZLII (ZL15 to ZL39) according to Examples. The movement directions of the lens groups along the optical axis upon zooming from the wide angle end state (W) to the telephoto end state (T) are indicated by arrows on the lower side of the cross-sectional views corresponding to the zoom optical systems ZL15 to ZL39. The movement direction of the focusing lens group GF (GA) upon focusing from infinity to a short-distant object and movement of the vibration-proof lens group VR upon image blur correction is indicated by arrows on the upper side of the cross-sectional views corresponding to the zoom optical systems ZL15 to ZL39.
Reference signs in FIG. 21 corresponding to Example 15 are independently provided for each Example, to avoid complication of description due to increase in the number of digits of the reference signs. Thus, reference signs that are the same as those in a drawing corresponding to another Example do not necessarily indicate a configuration that is the same as that in the other Example.
In Examples, d-line (wavelength 587.562 nm) and g-line (wavelength 435.835 nm) are selected as calculation targets of the aberration characteristics.
In [lens specifications] in the tables, a surface number represents an order of an optical surface from the object side in a traveling direction of a light beam, R represents a radius of curvature of each optical surface, D represents a distance between each optical surface and the next optical surface (or the image surface) on the optical axis, nd represents a refractive index of a material of an optical member with respect to the d-line, and υd represents Abbe number of the material of the optical member based on the d-line. Furthermore, obj surface represents an object surface, (variable) represents a variable surface distance, “∞” of a radius of curvature represents a plane or an aperture, (stop S) represents the aperture stop S, and img surface represents the image surface I. The refractive index “1.00000” of air is omitted. An aspherical optical surface has a * mark in the field of surface number and has a paraxial radius of curvature in the field of radius of curvature R.
In the table, [aspherical data] has the following formula (a) indicating the shape of an aspherical surface in [lens specifications]. In the formula, X(y) represents a distance between the tangent plane at the vertex of the aspherical surface and a position on the aspherical surface at a height y along the optical axis direction, R represents a radius of curvature (paraxial radius of curvature) of a reference spherical surface, K represents a conical coefficient, and Ai represents ith aspherical coefficient. In the formula, “E-n” represents “×10−n”. For example, 1.234E−05=1.234×10−5. A secondary aspherical coefficient A2 is 0, and thus is omitted.

X(y)=(y2/R)/{1(1−κ×y2/R2)1/2}A4×y4+A6×y6+A8×y8+A10×y10  (a)

In [various data] in Tables, f represents a focal length of the whole zoom lens; FNO represents F number, 2ω represents an angle of view (unit: °), Y represents the maximum image height, BF(air) represents a distance between the lens last surface and the image surface I on the optical axis upon focusing on infinity described with an air equivalent length, TL(air) represents a value obtained by adding BF(air) to the distance between the lens forefront surface and the lens last surface on the optical axis upon focusing on infinity.
In [variable distance data] in Tables, variable distance values Di in states such as the wide-angle end state, the intermediate focal length, and the telephoto end state are described. Di represents a variable distance between an ith surface and a (i+1)th surface.
In [lens group data] in Tables, the starting surface and the focal length of each of the lens groups are described.
In [conditional expression corresponding value] in Tables, values corresponding to the conditional expression are described.
The focal length f, the radius of curvature R, and the distance to the next lens surface D described below as the specification values, which are generally described with “mm” unless otherwise noted should not be construed in a limiting sense because the optical system proportionally expanded or reduced can have a similar or the same optical performance. The unit is not limited to “mm”, and other appropriate units may be used.
The description on Tables described above commonly applies to all Examples, and thus will not be described below.
Example 15
Example 15 is described with reference to FIG. 21 and Table 15. A zoom optical system ZLII (ZL15) according to Example 15 includes, as illustrated in FIG. 21, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 15, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.338 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.358 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.389 mm when the correction angle is 0.327°.
In Table 15 below, specification values in Example are listed. Surface numbers 1 to 33 in Table 15 respectively correspond to the optical surfaces m1 to m33 in FIG. 21.







TABLE 15







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
755.7151
2.00
22.74
1.80809


2
161.3459
5.78
67.90
1.59319


3
−580.4059
0.10


4
67.8395
5.80
54.61
1.72916


5
174.6045
 D5(variable)


6
76.4442
1.35
35.73
1.90265


7
18.5155
8.86


*8
−39.7788
1.00
51.15
1.75501


9
52.4007
0.10


10
40.3224
5.17
22.74
1.80809


11
−52.2736
2.86


12
−23.0648
1.20
58.12
1.62299


13
−42.3507
D13(variable)


*14
38.7318
3.48
51.15
1.75501


*15
−132.1314
1.00


16
∞
2.50
(aperture stop)


17
46.8922
5.22
82.57
1.49782


18
−42.6707
0.10


19
755.7937
1.00
37.18
1.83400


20
25.3493
D20(variable)


*21
32.5284
7.45
67.02
1.59201


22
−21.4485
1.00
23.80
1.84666


23
−37.3054
D23(variable)


24
−269.6872
4.53
22.74
1.80809


25
−22.2495
1.00
35.25
1.74950


26
33.9362
D26(variable)


27
39.0406
8.96
81.49
1.49710


28
−26.9857
1.06


29
−31.8633
4.36
22.74
1.80809


30
−27.4771
1.35
52.34
1.75500


31
−56.0731
3.74


32
−21.6584
1.30
54.61
1.72916


33
−45.4890
D33(variable)


Img surface
∞










[Aspherical data]












Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 4.46184E−06
6.59185E−09
−2.42201E−11
2.59662E−13


14th surface
0.00
−3.88209E−06
2.73780E−08
−1.55431E−10
0.00000E+00


15th surface
0.00
 7.82327E−06
2.51863E−08
−1.15048E−10
−1.28188E−13 


21st surface
0.00
−3.14303E−06
5.83544E−10
−1.13942E−11
0.00000E+00










[Various data]


Zoom ratio 4.13













Wide angle

Telephoto




end
Intermediate
end







f
24.7~
49.5~
102.0



FNO
2.9~
3.7~
4.1



2ω
82.4~
47.2~
23.5



Y
19.2~
21.6~
21.6



TL(air)
145.2~
160.9~
196.8



BF(air)
14.9~
28.9~
43.9











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
102.0
24.7
49.5
102.0


D5
1.10
19.44
48.07


D13
25.53
8.90
1.10


D20
10.87
10.87
10.87
10.20
8.66
2.09


D23
2.50
6.70
7.68
3.17
8.91
16.46


D26
8.08
3.88
2.90


D33
14.92
28.89
43.95










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
133.47



Second lens group
6
−20.32



Third lens group
14
30.32



Fourth lens group
24
−44.25



Fifth lens group
27
151.19











[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.178


Conditional expression(JK2) (−fXn)/fM = 0.670


Conditional expression(JK3) dAB/|fF| = 0.304


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JK5) νdp = 67.02


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 8.062


Conditional expression(JL2) |fF|/fM = 1.178


Conditional expression(JL3) dAB/|fF| = 0.304


Conditional expression(JL4) (−fXn)/fM = 0.670


Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JL6) νdp = 67.02


Conditional expression(JM1) dV/|fV| = 0.066


Conditional expression(JM2) |fF|/fM = 1.178


Conditional expression(JM3) dAB/|fF| = 0.304


Conditional expression(JM4) (−fXn)/fM = 0.670


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JM6) νdp = 67.02


Conditional expression(JN1) |fF|/fM = 1.178


Conditional expression(JN2) dV/|fV| = 0.066


Conditional expression(JN3) dAB/|fF| = 0.304


Conditional expression(JN4) (−fXn)/fM = 0.670


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JN6) νdp = 67.02









It can be seen in Table 15 that the zoom optical system ZL15 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 16
Example 16 is described with reference to FIG. 22 and Table 16. A zoom optical system ZLII (ZL16) according to Example 16 includes, as illustrated in FIG. 22, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image side; and the biconvex lens L34 that are arranged in order from the object side. The image side group GB includes a cemented lens including the biconvex lens L35 and a negative meniscus lens L36 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L35 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 16, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.364 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.380 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.411 mm when the correction angle is 0.327°.
In Table 16 below, specification values in Example are listed. Surface numbers 1 to 34 in Table 16 respectively correspond to the optical surfaces m1 to m34 in FIG. 22.







TABLE 16







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
916.8489
2.00
22.74
1.80809


2
158.3187
6.08
67.90
1.59319


3
−493.5781
0.10


4
63.9801
6.17
54.61
1.72916


5
163.4366
 D5(variable)


6
83.3961
1.35
35.72
1.90265


7
18.1108
8.76


*8
−40.2536
1.00
51.16
1.75501


9
68.0742
0.10


10
42.0171
5.22
22.74
1.80809


11
−46.3761
1.93


12
−25.6000
1.20
58.12
1.62299


13
−74.9844
D13(variable)


*14
29.1065
5.62
53.94
1.71300


*15
−124.6985
1.23


16
∞
1.18
(aperture stop)


17
39.1990
3.24
82.57
1.49782


18
126.0827
1.00
35.72
1.90265


19
23.4224
2.24


20
118.9234
1.83
82.57
1.49782


21
−101.4424
D21(variable)


*22
33.6941
7.47
67.02
1.59201


23
−21.0000
1.00
23.80
1.84666


24
−38.3994
D24(variable)


25
−6161.8654
5.21
23.80
1.84666


26
−20.1408
1.00
34.92
1.80100


27
33.4655
D27(variable)


28
37.1236
9.10
81.56
1.49710


29
−26.2445
0.10


30
−35.8475
3.96
22.74
1.80809


31
−31.3729
1.35
52.33
1.75500


32
−59.8216
4.09


33
−20.2772
1.30
54.61
1.72916


34
−47.4793
D34(variable)


Img surface
∞











[Aspherical data]













Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 3.42226E−06
6.05569E−09
−3.11555E−11
2.54097E−13


14th surface
0.00
−4.80738E−06
5.41541E−09
−4.65291E−11
0.00000E+00


15th surface
0.00
 3.66826E−06
1.07444E−09
−3.77085E−11
−1.05724E−14 


22nd surf ace
0.00
−1.57492E−06
3.71675E−09
−1.27040E−11
0.00000E+00










[Various data]


Zoom ratio 4.13













Wide angle

Telephoto




end
Intermediate
end







f
24.7~
49.5~
102.0



FNO
2.9~
3.7~
4.1



2ω
82.4~
47.2~
23.5



Y
19.1~
21.6~
21.6



TL(air)
145.0~
161.2~
195.8



BF(air))
14.9~
29.0~
43.7











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
102.0
24.7
49.5
102.0


D5
1.10
19.00
46.32


D13
24.37
8.60
1.10


D21
9.79
9.79
9.79
9.06
7.42
0.62


D24
2.50
6.73
7.54
3.23
9.10
16.70


D27
7.55
3.32
2.51


D34
14.92
28.97
43.69










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
127.20



Second lens group
6
−19.77



Third lens group
14
30.89



Fourth lens group
25
−45.90



Fifth lens group
28
151.64













[Conditional expression corresponding value]







Conditional expression(JK1) |fF|/fM = 1.217



Conditional expression(JK2) (−fXn)/fM = 0.640



Conditional expression(JK3) dAB/|fF| = 0.260



Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JK5) νdp = 67.02



Conditional expression(JM1) dV/|fV| = 0.055



Conditional expression(JM2) |fF|/fM = 1.217



Conditional expression(JM3) dAB/|fF| = 0.260



Conditional expression(JM4) (−fXn)/fM = 0.640



Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JM6) νdp = 67.02



Conditional expression(JN1) |fF|/fM = 1.217



Conditional expression(JN2) dV/|fV| = 0.055



Conditional expression(JN3) dAB/|fF| = 0.260



Conditional expression(JN4) (−fXn)/fM = 0.640



Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JN6) νdp = 67.02










It can be seen in Table 16 that the zoom optical system ZL16 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 17
Example 17 is described with reference to FIG. 23 and Table 17. A zoom optical system ZLII (ZL17) according to Example 17 includes, as illustrated in FIG. 23, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: a cemented lens including a plano-concave lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes a positive meniscus lens L31 having a convex surface facing the object side, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side. The positive meniscus lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 17, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.350 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.355 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.386 mm when the correction angle is 0.363°.
In Table 17 below, specification values in Example are listed. Surface numbers 1 to 33 in Table 17 respectively correspond to the optical surfaces m1 to m33 in FIG. 23.







TABLE 17







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
∞
2.00
22.74
1.80809


2
164.5846
4.60
67.90
1.59319


3
−389.8904
0.10


4
55.4599
5.31
54.61
1.72916


5
150.4285
 D5(variable)


6
54.6982
1.35
35.72
1.90265


7
16.8605
8.51


*8
−37.7660
1.00
51.16
1.75501


9
51.1682
0.10


10
36.5172
4.82
22.74
1.80809


11
−49.3429
2.60


12
−23.0376
1.20
58.12
1.62299


13
−60.9926
D13(variable)


*14
46.7844
2.29
51.16
1.75501


*15
5406.1506
1.00


16
∞
4.27
(aperture stop)


17
36.7260
5.45
82.57
1.49782


18
−36.4581
0.20


19
63.6179
1.01
37.18
1.83400


20
23.0943
D20


*21
28.3732
6.76
67.02
1.59201


22
−21.5653
1.00
23.80
1.84666


23
−41.8197
D23(variable)


24
−803.2372
4.05
22.74
1.80809


25
−23.2794
1.00
35.25
1.74950


26
31.2651
D26(variable)


27
41.1138
8.00
81.56
1.49710


28
−24.2908
2.40


29
−25.4480
1.91
22.74
1.80809


30
−22.3045
1.35
52.33
1.75500


31
−52.8943
3.61


32
−19.4109
1.30
54.61
1.72916


33
−36.3707
D33(variable)


Img surface
∞











[Aspherical data]













Surface number
κ
A4
A6
A8
A10





8th surface
0.00
3.61252E−06
1.12702E−08
−7.62519E−11
5.02576E−13


14th surface
0.00
1.31110E−05
2.61938E−08
 2.79550E−10
0.00000E+00


15th surface
0.00
2.79617E−05
3.21704E−08
 3.63604E−10
−1.50000E−13 


21st surface
0.00
−1.16278E−06 
−6.94619E−10 
−3.31502E−11
0.00000E+00










[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.7~
49.5~
82.4



FNO
2.9~
3.6~
4.1



2ω
82.4~
47.2~
28.8



Y
19.1~
21.6~
21.6



TL(air)
127.9~
142.1~
166.0



BF(air)
14.9~
29.3~
37.6











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
82.4
24.7
49.5
82.4


D5
1.10
14.23
34.24


D13
18.86
5.52
1.10


D20
7.01
7.01
7.01
6.36
5.03
2.15


D23
2.50
5.70
6.08
3.15
7.68
10.94


D26
6.33
3.13
2.75


D33
14.92
29.34
37.63










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
114.25



Second lens group
6
−18.62



Third lens group
14
26.30



Fourth lens group
24
−44.47



Fifth lens group
27
221.10













[Conditional expression corresponding value]







Conditional expression(JK1) |fF|/fM = 1.337



Conditional expression(JK2) (−fXn)/fM = 0.708



Conditional expression(JK3) dAB/|fF| = 0.199



Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JK5) νdp = 67.02



Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 9.750



Conditional expression(JL2) |fF|/fM = 1.337



Conditional expression(JL3) dAB/|fF| = 0.199



Conditional expression(JL4) (−fXn)/fM = 0.708



Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JL6) νdp = 67.02



Conditional expression(JM1) dV/|fV| = 0.062



Conditional expression(JM2) |fF|/fM = 1.337



Conditional expression(JM3) dAB/|fF| = 0.199



Conditional expression(JM4) (−fXn)/fM = 0.708



Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JM6) νdp = 67.02



Conditional expression(JN1) |fF|/fM = 1.337



Conditional expression(JN2) dV/|fV| = 0.062



Conditional expression(JN3) dAB/|fF| = 0.199



Conditional expression(JN4) (−fXn)/fM = 0.708



Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JN6) νdp = 67.02










It can be seen in Table 17 that the zoom optical system ZL17 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 18
Example 18 is described with reference to FIG. 24 and Table 18. A zoom optical system ZLII (ZL18) according to Example 18 includes, as illustrated in FIG. 24, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes the positive meniscus lens L31 having a convex surface facing the object side, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the negative meniscus lens L34 having a concave surface facing the image side, and the biconvex lens L35 arranged in order from the object side. The positive meniscus lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the biconvex lens L41 and the biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 18, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.380 mm when the correction angle is 0.664. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.373 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.379 mm when the correction angle is 0.363°.
In Table 18 below, specification values in Example are listed. Surface numbers 1 to 33 in Table 18 respectively correspond to the optical surfaces m1 to m33 in FIG. 24.







TABLE 18







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
477.6359
2.00
22.74
1.80809


2
130.7220
6.15
67.90
1.59319


3
−262.1234
0.10


4
45.8222
3.53
54.61
1.72916


5
65.7498
 D5(variable)


6
50.7306
1.35
35.72
1.90265


7
17.0914
8.44


*8
−32.4922
1.00
51.16
1.75501


9
52.3984
0.17


10
39.5501
5.00
22.74
1.80809


11
−45.2417
2.46


12
−21.0150
1.20
58.12
1.62299


13
−44.1009
D13(variable)


*14
42.6978
4.05
51.16
1.75501


*15
146.0908
1.00


16
∞
1.00
(aperture stop)


17
33.8176
6.49
82.57
1.49782


18
−31.9561
0.10


19
77.2065
1.00
37.18
1.83400


20
24.0818
D20(variable)


*21
24.6808
1.00
24.06
1.82115


22
16.8495
8.03
67.90
1.59319


23
−56.7300
D23(variable)


24
2528.2943
8.17
22.74
1.80809


25
−17.9755
1.00
35.25
1.74950


26
28.0350
D26(variable)


27
37.6901
8.33
81.56
1.49710


28
−21.5347
0.10


29
−26.4036
0.51
22.74
1.80809


30
−36.3850
1.35
52.33
1.75500


31
−53.3386
3.71


32
−18.6338
1.30
54.61
1.72916


33
−37.2073
D33(variable)


Img surface
∞










[Aspherical data]












Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 5.54472E−06
 1.39612E−08
−1.09701E−10
7.98071E−13


14th surface
0.00
−1.56610E−07
−6.56482E−08
−8.11234E−11
0.00000E+00


15th surface
0.00
 1.77641E−05
−6.07679E−08
−3.87866E−11
1.00000E−17


21st surface
0.00
−2.60317E−06
−8.10030E−10
−3.36331E−11
0.00000E+00










[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end







f
24.7~
49.5~
82.5



FNO
2.9~
3.9~
4.1



2ω
82.4~
47.2~
28.8



Y
19.1~
21.6~
21.6



TL(air)
127.5~
144.9~
171.9



BF(air)
14.9~
30.1~
41.9












[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
82.5
24.7
49.5
82.5


D5
1.10
16.11
35.76


D13
18.31
5.55
1.10


D20
6.00
6.00
6.00
5.35
3.94
0.92


D23
2.50
5.48
5.88
3.15
7.54
10.97


D26
6.14
3.16
2.76


D33
14.92
30.05
41.88










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
132.75



Second lens group
6
−18.98



Third lens group
14
25.60



Fourth lens group
24
−43.35



Fifth lens group
27
226.32











[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.338


Conditional expression(JK2) (−fXn)/fM = 0.741


Conditional expression(JK3) dAB/|fF| = 0.175


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JK5) νdp = 67.90


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 81.411


Conditional expression(JL2) |fF|/fM = 1.338


Conditional expression(JL3) dAB/|fF| = 0.175


Conditional expression(JL4) (−fXn)/fM = 0.741


Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JL6) νdp = 67.90


Conditional expression(JM1) dV/|fV| = 0.064


Conditional expression(JM2) |fF|/fM = 1.338


Conditional expression(JM3) dAB/|fF| = 0.175


Conditional expression(JM4) (−fXn)/fM = 0.741


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JM6) νdp = 67.90


Conditional expression(JN1) |fF|/fM = 1.338


Conditional expression(JN2) dV/|fV| = 0.064


Conditional expression(JN3) dAB/|fF| = 0.175


Conditional expression(JN4) (−fXn)/fM = 0.741


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JN6) νdp = 67.90









It can be seen in Table 18 that the zoom optical system ZL18 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 19
Example 19 is described with reference to FIG. 25 and Table 19. A zoom optical system ZLII (ZL19) according to Example 19 includes, as illustrated in FIG. 25, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 having negative refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes: a cemented lens including the biconvex lens L41 and the biconcave lens L42; the biconvex lens L43; and the negative meniscus lens L44 having a concave surface facing the object side that are arranged in order from the object side. The biconvex lens L43 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the third lens group G3 and the fourth lens group G4 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the cemented lens including the biconvex lenses L41 and the biconcave lens L42 forming the fourth lens group G4, and serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 19, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.506 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.449 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.446 mm when the correction angle is 0.401°.
In Table 19 below, specification values in Example are listed. Surface numbers 1 to 30 in Table 19 respectively correspond to the optical surfaces m1 to m30 in FIG. 25.







TABLE 19







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
1193.7961
2.00
22.74
1.80809


2
124.6072
5.44
67.90
1.59319


3
−251.5182
0.10


4
53.9338
4.39
54.61
1.72916


5
148.4536
 D5(variable)


6
52.0263
1.35
35.72
1.90265


7
15.1015
7.62


*8
−30.5049
1.00
51.16
1.75501


9
93.9602
0.10


10
39.5192
4.07
22.74
1.80809


11
−41.3448
1.99


12
−20.4648
1.20
58.12
1.62299


13
−53.5027
D13(variable)


*14
213.8825
1.87
51.16
1.75501


*15
−64.5513
1.00


16
∞
3.38
(aperture stop)


17
110.8652
8.03
82.57
1.49782


18
−18.2246
0.48


19
116.2881
1.00
37.18
1.83400


20
28.0153
D20(variable)


*21
30.2797
6.11
67.02
1.59201


22
−21.0000
1.33
23.80
1.84666


23
−44.7009
D23(variable)


24
549.5106
3.21
22.74
1.80809


25
−38.9378
1.00
42.73
1.83481


26
44.8125
0.94


*27
53.1149
5.61
81.56
1.49710


28
−41.5964
8.34


29
−16.1731
1.30
50.67
1.67790


30
−40.6492
D30(variable)


Img surface
∞











[Aspherical data]













Surface number
κ
A4
A6
A8
A10





8th surf ace
0.00
 5.94537E−06
−1.85599E−09 
 5.98429E−11
6.60655E−13


14th surface
0.00
−4.52248E−05
7.78703E−08
−1.06200E−09
0.00000E+00


15thsurface
0.00
−6.29335E−06
1.07534E−07
−1.16673E−10
1.00000E−17


21st surface
0.00
−3.63068E−06
2.68872E−08
−2.41333E−11
0.00000E+00


27th surface
0.00
 1.77742E−05
−4.96065E−09 
 1.03075E−10
0.00000E+00










[Various data]


Zoom ratio 2.75













Wide angle

Telephoto




end
Intermediate
end







f
24.7~
49.5~
67.9



FNO
2.9~
3.9~
4.1



2ω
82.4~
47.0~
34.7



Y
19.1~
21.6~
21.6



TL(air)
110.8~
131.5~
145.4



BF(air)
14.9~
30.3~
37.7











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
67.9
24.7
49.5
67.9


D5
1.10
16.06
26.09


D13
11.54
3.19
1.10


D20
5.19
5.19
5.19
4.36
2.99
1.69


D23
5.16
3.92
2.50
5.99
6.11
5.99


D30
14.90
30.26
37.67










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
98.67



Second lens group
6
−17.73



Third lens group
14
24.81



Fourth lens group
24
−48.06













[Conditional expression corresponding value]







Conditional expression(JK1) |fF|/fM = 1.566



Conditional expression(JK2) (−fXn)/fM = 0.715



Conditional expression(JK3) dAB/|fF| = 0.133



Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JK5) νdp = 67.02



Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 25.744



Conditional expression(JL2) |fF|/fM = 1.566



Conditional expression(JL3) dAB/|fF| = 0.133



Conditional expression(JL4) (−fXn)/fM = 0.715



Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JL6) νdp = 67.02



Conditional expression(JM1) dV/|fV| = 0.017



Conditional expression(JM2) |fF|/fM = 1.566



Conditional expression(JM3) dAB/|fF| = 0.133



Conditional expression(JM4) (−fXn)/fM = 0.715



Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JM6) νdp = 67.02










It can be seen in Table 19 that the zoom optical system ZL19 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), and (JM1) to (JM6).
Example 20
Example 20 is described with reference to FIG. 26 and Table 20. A zoom optical system ZLII (ZL20) according to Example 20 includes, as illustrated in FIG. 26, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the positive meniscus lens L41 having a convex surface facing the image side and the biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 20, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.226 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.241 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.274 mm when the correction angle is 0.327°.
In Table 20 below, specification values in Example are listed. Surface numbers 1 to 33 in Table 20 respectively correspond to the optical surfaces m1 to m33 in FIG. 26.







TABLE 20







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
282.7218
1.33
22.74
1.80809


2
94.7445
6.10
67.90
1.59319


3
−226.9827
0.10


4
40.7799
3.54
54.61
1.72916


5
73.5746
 D5(variable)


6
49.4466
0.90
35.72
1.90265


7
12.2660
5.90


*8
−22.9424
0.90
51.16
1.75501


9
36.0329
0.13


10
28.3106
3.27
22.74
1.80809


11
−33.3406
1.61


12
−16.3903
0.90
58.12
1.62299


13
−28.7665
D13(variable)


*14
27.1836
1.87
51.16
1.75501


*15
−883.8798
1.00


16
∞
1.74
(aperture stop)


17
29.1431
3.58
82.57
1.49782


18
−27.0053
0.10


19
90.6365
0.93
37.18
1.83400


20
16.9325
D20(variable)


*21
21.6272
4.71
67.02
1.59201


22
−15.3834
0.67
23.80
1.84666


23
−27.6370
D23(variable)


24
−197.6287
2.84
22.74
1.80809


25
−16.1995
0.90
35.25
1.74950


26
24.2531
D26(variable)


27
29.8965
5.67
81.56
1.49710


28
−16.6499
0.85


29
−18.7793
1.65
22.74
1.80809


30
−17.2583
0.90
52.33
1.75500


31
−25.1119
1.61


32
−14.5032
0.90
54.61
1.72916


33
−34.8046
D33(variable)


Img surface
∞











[Aspherical data]













Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 1.17630E−05
3.52411E−08
−1.08429E−09
1.00133E−11


14th surface
0.00
−1.66916E−06
1.91542E−07
−3.91949E−09
0.00000E+00


15th surface
0.00
 3.85171E−05
2.06325E−07
−3.70351E−09
−2.61997E−12 


21st surface
0.00
−5.08719E−06
5.18792E−09
−3.38472E−10
0.00000E+00










[Various data]


Zoom ratio 4.13













Wide angle

Telephoto




end
Intermediate
end







f
16.5~
33.0~
68.0



FNO
2.9~
3.6~
4.1



2ω
81.7~
46.7~
23.2



Y
12.6~
14.3~
14.3



TL(air)
99.5~
111.4~
133.9



BF(air)
14.0~
23.8~
32.9











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.5
33.0
68.0
16.5
33.0
68.0


D5
1.00
13.94
32.81


D13
17.01
6.25
0.73


D20
6.71
6.71
6.71
6.43
5.79
3.08


D23
1.50
3.72
4.55
1.78
4.65
8.18


D26
4.68
2.46
1.63


D33
14.00
23.77
32.89










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
86.55



Second lens group
6
−13.34



Third lens group
14
20.21



Fourth lens group
24
−31.69



Fifth lens group
27
90.43













[Conditional expression corresponding value]







Conditional expression(JK1) |fF|/fM = 1.231



Conditional expression(JK2) (−fXn)/fM = 0.660



Conditional expression(JK3) dAB/|fF| = 0.270



Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JK5) νdp = 67.02



Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 8.213



Conditional expression(JL2) |fF|/fM = 1.231



Conditional expression(JL3) dAB/|fF| = 0.270



Conditional expression(JL4) (−fXn)/fM = 0.660



Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JL6) νdp = 67.02



Conditional expression(JM1) dV/|fV| = 0.051



Conditional expression(JM2) |fF|/fM = 1.231



Conditional expression(JM3) dAB/|fF| = 0.270



Conditional expression(JM4) (−fXn)/fM = 0.660



Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JM6) νdp = 67.02



Conditional expression(JN1) |fF|/fM = 1.231



Conditional expression(JN2) dV/|fV| = 0.051



Conditional expression(JN3) dAB/|fF| = 0.270



Conditional expression(JN4) (−fXn)/fM = 0.660



Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JN6) νdp = 67.02










It can be seen in Table 20 that the zoom optical system ZL20 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 21
Example 21 is described with reference to FIG. 27 and Table 21. A zoom optical system ZLII (ZL21) according to Example 21 includes, as illustrated in FIG. 27, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes: the cemented lens including the biconvex lens L41 and the biconcave lens L42; the biconvex lens L43; and the negative meniscus lens L44 having a concave surface facing the object side that are arranged in order from the object side. The biconvex lens L43 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fifth lens group G5 includes a plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 each moved toward the object side, and the fifth lens group G5 fixed in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the cemented lens including the biconvex lenses L41 and the biconcave lens L42 forming the fourth lens group G4, and serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 21, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.568 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.473 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.498 mm when the correction angle is 0.401°.
In Table 21 below, specification values in Example are listed. Surface numbers 1 to 32 in Table 21 respectively correspond to the optical surfaces m1 to m32 in FIG. 27.







TABLE 21







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞


1
1587.6950
2.00
22.74
1.80809


2
129.2311
5.54
67.90
1.59319


3
−234.0081
0.10


4
49.3184
4.83
54.61
1.72916


5
133.6129
 D5(variable)


6
50.3607
1.35
35.72
1.90265


7
13.9849
7.29


*8
−26.5646
1.00
51.16
1.75501


9
75.5170
0.10


10
37.4790
4.06
22.74
1.80809


11
−33.7046
1.73


12
−19.4446
1.20
58.12
1.62299


13
−45.6085
D13(variable)


*14
213.8825
1.67
51.16
1.75501


*15
−82.3988
1.00


16
∞
3.03
(aperture stop)


17
94.6893
7.99
82.57
1.49782


18
−17.1738
0.71


19
111.0410
1.07
37.18
1.83400


20
27.8731
D20(variable)


*21
30.7270
5.62
67.02
1.59201


22
−21.0000
1.00
23.80
1.84666


23
−41.6131
D23(variable)


24
199.8522
2.64
22.74
1.80809


25
−71.5415
1.00
39.61
1.80440


26
39.6118
1.67


*27
69.1913
5.36
81.56
1.49710


28
−38.3308
6.47


29
−15.4809
1.30
55.52
1.69680


30
−44.4855
D30(variable)


31
147.3134
2.68
23.80
1.84666


32
∞
D32(variable)


Img surface
∞











[Aspherical data]













Surface number
κ
A4
A6
A8
A10





8th surface
0.00
8.49130E−06
−5.54309E−09 
 7.89989E−11
9.93584E−13


14th surface
0.00
−4.27481E−05 
3.37131E−07
−3.01232E−09
0.00000E+00


15th surface
0.00
3.68942E−06
3.86199E−07
−1.66414E−09
1.00000E−17


21st surface
0.00
−4.28039E−06 
3.72554E−08
−4.57534E−11
0.00000E+00


27th surface
0.00
2.35154E−05
−3.28269E−09 
 1.82075E−10
0.00000E+00










[Various data]


Zoom ratio 2.75













Wide angle

Telephoto




end
Intermediate
end







f
24.7~
49.5~
67.9



FNO
2.9~
4.1~
4.1



2ω
82.4~
47.2~
34.7



Y
19.1~
21.6~
21.6



TL(air)
108.3~
131.2~
145.7



BF(air)
14.0~
14.0~
14.0











[Variable distance data]










Upon focusing on infinity
Upon focusing on short distant object














Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
67.9
24.7
49.5
67.9


D5
1.10
13.33
25.21


D13
9.54
2.72
1.10


D20
4.02
4.02
4.02
3.22
2.12
0.92


D23
5.77
3.65
2.50
6.56
5.54
5.60


D30
1.50
21.08
26.51


D32
14.00
14.00
14.00










[Lens group data]












Group
Group




starting surface
focal length







First lens group
1
90.94



Second lens group
6
−16.97



Third lens group
14
23.60



Fourth lens group
24
−40.81



Fifth lens group
31
173.99













[Conditional expression corresponding value]







Conditional expression(JK1) |fF|/fM = 1.579



Conditional expression(JK2) (−fXn)/fM = 0.719



Conditional expression(JK3) dAB/|fF| = 0.108



Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JK5) νdp = 67.02



Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 20.533



Conditional expression(JL2) |fF|/fM = 1.579



Conditional expression(JL3) dAB/|fF| = 0.108



Conditional expression(JL4) (−fXn)/fM = 0.719



Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JL6) νdp = 67.02



Conditional expression(JM1) dV/|fV| = 0.027



Conditional expression(JM2) |fF|/fM = 1.579



Conditional expression(JM3) dAB/|fF| = 0.108



Conditional expression(JM4) (−fXn)/fM = 0.719



Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JM6) νdp = 67.02



Conditional expression(JN1) |fF|/fM = 1.579



Conditional expression(JN2) dV/|fV| = 0.027



Conditional expression(JN3) dAB/|fF| = 0.108



Conditional expression(JN4) (−fXn)/fM = 0.719



Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.080



Conditional expression(JN6) νdp = 67.02










It can be seen in Table 21 that the zoom optical system ZL21 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 22
Example 22 is described with reference to FIG. 28 and Table 22. A zoom optical system ZLII (ZL22) according to Example 22 includes, as illustrated in FIG. 28, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image side; and a plano-convex lens L34 having a convex surface facing the object side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L35 and the negative meniscus lens L36 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L35 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the biconvex lens L41 and the biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 22, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.411 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.410 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.457 mm when the correction angle is 0.327°.
In Table 22 below, specification values in Example are listed. Surface numbers 1 to 34 in Table 22 respectively correspond to the optical surfaces m1 to m34 in FIG. 28.







TABLE 22







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
524.4509
2.00
22.74
1.80809


2
136.5814
6.32
67.90
1.59319


3
−713.0593
0.10




4
65.1416
6.39
54.61
1.72916


5
186.0464
 D5(variable)




6
108.5540
1.35
35.72
1.90265


7
18.6469
8.64




*8
−40.1904
1.00
51.16
1.75501


9
65.4869
0.10




10
43.0188
5.29
22.74
1.80809


11
−46.1246
2.17




12
−26.2743
1.20
58.12
1.62299


13
−65.0579
D13(variable)




*14
27.5180
5.10
53.94
1.71300


*15
−84.3430
1.00




16
∞
1.00
(aperture stop)



17
62.3923
2.81
82.57
1.49782


18
214.3713
1.00
35.72
1.90265


19
23.1110
1.60




20
49.5946
2.41
82.57
1.49782


21
∞
D21(variable)




*22
35.3414
7.32
67.02
1.59201


23
−21.4664
1.00
23.80
1.84666


24
−38.1772
D24(variable)




25
319.0764
5.02
23.80
1.84666


26
−22.4269
1.00
34.92
1.80100


27
33.3745
D27(variable)




28
33.9494
8.88
81.56
1.49710


29
−26.6215
0.73




30
−30.2862
3.94
22.74
1.80809


31
−28.5529
1.35
52.33
1.75500


32
−61.3691
4.03




33
−20.0622
1.30
54.61
1.72916


34
−43.5447
D34(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 3.38423E−06
 2.84604E−09
−1.31614E−11
 1.46359E−13


14th surface
0.00
−4.98461E−06
−5.66401E−10
 1.28428E−11
 0.00000E+00


15th surface
0.00
 6.02589E−06
−9.27295E−09
 6.23729E−11
−1.21951E−13


22nd surface
0.00
−7.15516E−07
 1.57972E−09
−6.46596E−12
 0.00000E+00










[Various data]


Zoom ratio 4.13













Wide angle

Telephoto




end
Intermediate
end






f
24.7~
49.5~
102.0



FNO
2.9~
3.7~
4.1



2ω
82.4~
47.2~
23.5



Y
19.1~
21.5~
21.6



TL(air)
146.1~
161.6~
194.8



BF(air)
14.9~
30.2~
43.4











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
102.0
24.7
49.5
102.0


D5
1.10
17.10
44.71





D13
24.52
8.75
1.10





D21
12.24
12.24
12.24
11.44
9.69
1.62


D24
2.50
6.02
6.72
3.31
8.58
17.34


D27
6.72
3.20
2.50





D34
14.92
30.24
43.44










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
121.41



Second lens group
6
−20.01



Third lens group
14
32.50



Fourth lens group
25
−52.38



Fifth lens group
28
201.85










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.174


Conditional expression(JK2) (−fXn)/fM = 0.616


Conditional expression(JK3) dAB/|fF| = 0.321


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JK5) νdp = 67.02


Conditional expression(JM1) dV/|fV| = 0.048


Conditional expression(JM2) |fF|/fM = 1.174


Conditional expression(JM3) dAB/|fF| = 0.321


Conditional expression(JM4) (−fXn)/fM = 0.616


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JM6) νdp = 67.02


Conditional expression(JN1) |fF|/fM = 1.174


Conditional expression(JN2) dV/|fV| = 0.048


Conditional expression(JN3) dAB/|fF| = 0.321


Conditional expression(JN4) (−fXn)/fM = 0.616


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JN6) νdp = 67.02









It can be seen in Table 22 that the zoom optical system ZL22 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 23
Example 23 is described with reference to FIG. 29 and Table 23. A zoom optical system ZLII (ZL23) according to Example 23 includes, as illustrated in FIG. 29, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the object side and the negative meniscus lens L33 having a concave surface facing the image side; and a positive meniscus lens L34 having a convex surface facing the object side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L35 and the negative meniscus lens L36 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L35 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the biconvex lens L41 and the biconcave lens L42 arranged in order from the object side.
The fifth lens group G5 includes: the biconvex lens L51; the cemented lens including the positive meniscus lens L52 having a convex surface facing the image side and the negative meniscus lens L53 having a concave surface facing the object side; and the negative meniscus lens L54 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 23, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.421 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.397 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.464 mm when the correction angle is 0.327°.
In Table 23 below, specification values in Example are listed. Surface numbers 1 to 34 in Table 23 respectively correspond to the optical surfaces m1 to m34 in FIG. 29.







TABLE 23







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
397.6225
2.00
22.74
1.80809


2
126.6607
6.12
67.90
1.59319


3
−1629.7121
0.10




4
66.2175
6.51
54.61
1.72916


5
204.9442
 D5(variable)




6
119.6650
1.35
35.72
1.90265


7
18.8679
8.64




*8
−41.4130
1.00
51.16
1.75501


9
67.3512
0.19




10
43.6021
5.30
22.74
1.80809


11
−47.3970
2.28




12
−27.7631
1.20
58.12
1.62299


13
−74.8409
D13(variable)




*14
30.2719
5.48
53.94
1.71300


*15
−65.5930
1.00




16
∞
1.00
(aperture stop)



17
58.3076
2.76
82.57
1.49782


18
153.8064
1.00
35.72
1.90265


19
22.3628
0.82




20
28.2979
2.36
82.57
1.49782


21
60.0000
D21(variable)




*22
35.7069
7.36
67.02
1.59201


23
−21.0000
1.00
23.80
1.84666


24
−36.3549
D24(variable)




25
333.6098
4.93
23.80
1.84666


26
−23.0108
1.00
34.92
1.80100


27
34.3183
D27(variable)




28
33.2532
8.91
81.56
1.49710


29
−26.1918
1.34




30
−25.2656
3.92
22.74
1.80809


31
−24.0934
1.35
52.33
1.75500


32
−50.9794
3.37




33
−21.5738
1.30
54.61
1.72916


34
−47.3035
D34(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 3.02942E−06
−2.29162E−09
1.69922E−11
2.36654E−14


14th surface
0.00
−4.74032E−06
 1.79300E−09
2.08922E−11
0.00000E+00


15th surface
0.00
 6.90940E−06
−9.71049E−09
7.91702E−11
−1.50000E−13 


22nd surface
0.00
−7.40532E−07
 1.38738E−09
−6.12998E−12 
0.00000E+00










[Various data]


Zoom ratio 4.13













Wide angle

Telephoto




end
Intermediate
end






f
24.7~
49.5~
102.0



FNO
2.9~
3.9~
4.1



2ω
82.4~
47.2~
23.5



Y
19.1~
21.4~
21.6



TL(air)
146.4~
159.9~
195.1



BF(air)
14.9~
32.8~
43.9











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
102.0
24.7
49.5
102.0


D5
1.10
13.06
44.28





D13
24.59
8.18
1.10





D21
13.15
13.15
13.15
12.34
10.61
1.63


D24
2.50
5.87
6.56
3.31
8.42
18.08


D27
6.56
3.19
2.50





D34
14.92
32.82
43.94










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
120.70



Second lens group
6
−19.97



Third lens group
14
32.84



Fourth lens group
25
−53.72



Fifth lens group
28
218.02










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.135


Conditional expression(JK2) (−fXn)/fM = 0.608


Conditional expression(JK3) dAB/|fF| = 0.353


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JK5) νdp = 67.02


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 3.940


Conditional expression(JL2) |fF|/fM = 1.135


Conditional expression(JL3) dAB/|fF| = 0.353


Conditional expression(JL4) (−fXn)/fM = 0.608


Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JL6) νdp = 67.02


Conditional expression(JM1) dV/|fV| = 0.047


Conditional expression(JM2) |fF|/fM = 1.135


Conditional expression(JM3) dAB/|fF| = 0.353


Conditional expression(JM4) (−fXn)/fM = 0.608


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JM6) νdp = 67.02


Conditional expression(JN1) |fF|/fM = 1.135


Conditional expression(JN2) dV/|fV| = 0.047


Conditional expression(JN3) dAB/|fF| = 0.353


Conditional expression(JN4) (−fXn)/fM = 0.608


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JN6) νdp = 67.02









It can be seen in Table 23 that the zoom optical system ZL23 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 24
Example 24 is described with reference to FIG. 30 and Table 24. A zoom optical system ZLII (ZL24) according to Example 24 includes, as illustrated in FIG. 30, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 having negative refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including a plano-concave lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes the biconvex lens L31, the aperture stop S, the biconvex lens L32, and the negative meniscus lens L33 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the biconvex lens L34 and the negative meniscus lens L35 having a concave surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes: the cemented lens including the biconvex lens L41 and the biconcave lens L42; the biconvex lens L43; and the negative meniscus lens L44 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the third lens G3 and the fourth lens G4 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the cemented lens including the biconvex lenses L41 and the biconcave lens L42 forming the fourth lens group G4, and serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 24, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.508 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.445 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.457 mm when the correction angle is 0.401°.
In Table 24 below, specification values in Example are listed. Surface numbers 1 to 30 in Table 24 respectively correspond to the optical surfaces m1 to m30 in FIG. 30.







TABLE 24







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
∞
2.00
22.74
1.80809


2
145.2414
5.36
67.90
1.59319


3
−208.7932
0.10




4
51.2812
4.29
54.61
1.72916


5
123.8115
 D5(variable)




6
53.8612
1.35
35.72
1.90265


7
15.5357
7.82




*8
−31.1374
1.00
51.16
1.75501


9
101.4389
0.10




10
39.7482
4.19
22.74
1.80809


11
−43.3059
2.15




12
−21.9691
1.20
58.12
1.62299


13
−56.9086
D13(variable)




*14
213.8825
1.79
51.16
1.75501


*15
−72.7193
1.00




16
∞
3.98
(aperture stop)



17
97.9971
6.38
82.57
1.49782


18
−18.5448
0.10




19
94.3665
1.00
37.18
1.83400


20
26.1587
D20(variable)




*21
30.3808
6.11
67.02
1.59201


22
−21.3812
1.60
23.80
1.84666


23
−42.2061
D23(variable)




24
141.2342
3.02
22.74
1.80809


25
−55.9270
1.00
42.73
1.83481


26
35.7911
2.00




*27
48.1163
5.74
81.56
1.49710


28
−42.2113
7.39




29
−15.9575
1.30
50.67
1.67790


30
−48.0365
D30(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





8th surface
0.00
 3.84120E−06
−6.26512E−09
 3.47226E−11
3.83750E−13


14th surface
0.00
−4.20763E−05
 2.15227E−08
−1.41711E−09
0.00000E+00


15th surface
0.00
−1.39681E−06
 5.82933E−08
−5.07924E−10
1.00000E−17


21st surface
0.00
−8.84366E−07
 3.28772E−08
−5.31778E−11
0.00000E+00


27th surface
0.00
 1.93046E−05
−6.37415E−09
 1.44751E−10
0.00000E+00










[Various data]


Zoom ratio 2.75













Wide angle

Telephoto




end
Intermediate
end






f
24.7~
49.5~
67.9



FNO
2.9~
4.0~
4.1



2ω
82.4~
47.1~
34.7



Y
19.1~
21.6~
21.6



TL(air)
108.8~
127.9~
142.1



BF(air)
14.9~
30.6~
36.3











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
67.9
24.7
49.5
67.9


D5
1.10
14.75
26.43





D13
12.16
3.25
1.10





D20
3.76
3.76
3.76
2.98
1.76
0.50


D23
4.96
3.57
2.50
5.73
5.57
5.75


D30
14.90
30.58
36.31










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
100.26



Second lens group
6
−18.73



Third lens group
14
24.21



Fourth lens group
24
−43.18










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.537


Conditional expression(JK2) (−fXn)/fM = 0.774


Conditional expression(JK3) dAB/|fF| = 0.101


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JK5) νdp = 67.02


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 13.391


Conditional expression(JL2) |fF|/fM = 1.537


Conditional expression(JL3) dAB/|fF| = 0.101


Conditional expression(JL4) (−fXn)/fM = 0.774


Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JL6) νdp = 67.02


Conditional expression(JM1) dV/|fV| = 0.036


Conditional expression(JM2) |fF|/fM = 1.537


Conditional expression(JM3) dAB/|fF| = 0.101


Conditional expression(JM4) (−fXn)/fM = 0.774


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.080


Conditional expression(JM6) νdp = 67.02









It can be seen in Table 24 that the zoom optical system ZL24 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), and (JM1) to (JM6).
Example 25
Example 25 is described with reference to FIG. 31 and Table 25. A zoom optical system ZLII (ZL25) according to Example 25 includes, as illustrated in FIG. 31, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the biconcave lens L21, the biconcave lens L22, and the biconvex lens L23 that are arranged in order from the object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having a concave surface facing the object side; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes a positive meniscus lens L35 having a convex surface facing the object side. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a negative meniscus lens L41 having a concave surface facing the image side. The negative meniscus lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, the third lens group G3 and the fourth lens group G4 moved toward the object side, and the fifth lens group G5 moved toward the object side and then moved toward the image side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between fourth lens group G4 and the fifth lens group G5 increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
In Table 25 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 25 respectively correspond to the optical surfaces m1 to m23 in FIG. 31.







TABLE 25







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
36.6683
1.48
23.78
1.84666


2
26.2009
5.77
52.33
1.75500


3
361.1070
 D3(variable)




4
−988.0287
1.00
35.25
1.91082


5
12.7389
5.67




*6
−91.2065
1.10
40.10
1.85135


7
42.5712
0.55




8
29.0506
2.84
20.88
1.92286


9
−105.9692
 D9(variable)




10
19.3382
1.70
63.34
1.61800


11
42.9857
1.80




12
∞
1.50
(aperture stop)



13
34.2676
3.37
70.32
1.48749


14
−14.1924
1.00
25.45
1.80518


15
−36.1986
0.98




*16
−17.6970
2.65
54.61
1.72916


17
−12.3843
D17(variable)




18
20.7895
1.76
55.52
1.69680


19
122.6193
D19(variable)




*20
59.8462
1.00
40.10
1.85135


*21
12.8981
D21(variable)




22
92.0042
3.06
40.98
1.58144


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
5.44650E−06
 1.29656E−09
2.84992E−10
 3.06572E−12


16th surface
0.00
−1.22072E−04 
 1.22532E−07
4.84068E−10
−4.09604E−11


20th surface
0.00
1.71663E−04
−5.28544E−06
5.66102E−08
−2.66106E−10


21st surface
0.00
1.44420E−04
−5.59342E−06
5.88893E−08
−2.77861E−10










[Various data]


Zoom ratio 2.89













Wide angle

Telephoto




end
Intermediate
end






f
18.5~
27.9~
53.5



FNO
2.9~
3.4~
4.3



2ω
75.2~
52.4~
28.1



Y
13.2~
14.3~
14.3



TL(air)
77.7~
80.0~
94.4



BF(air)
17.0~
22.6~
14.4











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
18.5
27.9
53.5
18.5
27.9
53.5


D3
0.80
5.65
14.75





D9
15.54
7.64
0.80





D17
1.96
1.96
1.96
1.42
1.06
0.04


D19
2.99
2.19
1.00
3.52
3.09
2.93


D21
2.22
2.78
24.28





D23
17.01
22.58
14.40










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
56.37



Second lens group
4
−19.13



Third lens group
10
15.30



Fourth lens group
20
−19.50



Fifth lens group
22
158.24










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 2.331


Conditional expression(JK2) (−fXn)/fM = 1.250


Conditional expression(JK3) dAB/|fF| = 0.055


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.062


Conditional expression(JK5) νdp = 55.52


Conditional expression(JN1) |fF|/fM = 2.331


Conditional expression(JN3) dAB/|fF| = 0.055


Conditional expression(JN4) (−fXn)/fM = 1.250


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.062


Conditional expression(JN6) νdp = 55.52









It can be seen in Table 25 that the zoom optical system ZL25 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JN1), and (JN3) to (JN6).
Example 26
Example 26 is described with reference to FIG. 32 and Table 26. A zoom optical system ZLII (ZL26) according to Example 26 includes, as illustrated in FIG. 32, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the image side and the negative meniscus lens L33 having a concave surface facing the object side; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the positive meniscus lens L35 having a convex surface facing the object side. The biconcave lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes a biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 26, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.142 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.142 mm when the correction angle is 0.519°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.136 mm when the correction angle is 0.387°.
In Table 26 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 26 respectively correspond to the optical surfaces m1 to m23 in FIG. 32.







TABLE 26







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
36.5281
1.40
17.98
1.94594


2
29.1276
5.83
52.33
1.75500


3
158.4438
 D3(variable)




4
91.2316
1.00
40.66
1.88300


5
9.7507
6.11




*6
−25.4624
1.10
40.10
1.85135


*7
−171.2605
0.14




8
64.1510
1.87
17.98
1.94594


9
−60.1639
 D9(variable)




*10
17.6788
2.18
58.16
1.62263


11
−71.7572
1.80




12
∞
1.50
(aperture stop)



13
−129.8844
5.00
82.57
1.49782


14
−13.2317
1.00
28.69
1.79504


15
−75.6261
1.33




*16
−17.8346
1.81
58.16
1.62263


17
−10.4367
D17(variable)




18
15.0659
2.01
82.57
1.49782


19
244.7635
D19(variable)




*20
−273.7319
1.00
40.10
1.85135


*21
13.8657
D21(variable)




22
24.2495
2.85
33.72
1.64769


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−3.45636E−05
−6.64811E−07
 2.82299E−09
−7.04101E−11


7th surface
0.00
−6.04474E−05
−4.14108E−07
−2.06673E−09
 0.00000E+00


10th surface
0.00
−2.20361E−05
−2.04696E−08
−1.19959E−09
 0.00000E+00


16th surface
0.00
−1.68079E−04
 4.19181E−07
−1.19913E−08
 6.38223E−11


20th surface
0.00
 1.19790E−04
−5.17513E−06
 8.76145E−08
−6.53217E−10


21st surface
0.00
 6.19772E−05
−4.74095E−06
 8.40067E−08
−6.36691E−10










[Various data]


Zoom ratio 2.94













Wide angle

Telephoto




end
Intermediate
end






f
16.5~
26.9~
48.5



FNO
2.9~
3.3~
4.1



2ω
81.7~
55.8~
31.9



Y
12.5~
14.1~
14.3



TL(air)
77.2~
83.7~
98.0



BF(air)
17.0~
23.9~
35.5











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.5
26.9
48.5
16.5
26.9
48.5


D3
0.80
8.80
18.28





D9
13.20
5.98
0.80





D17
1.95
1.95
1.95
1.50
1.06
0.05


D19
2.29
2.09
1.00
2.74
2.99
2.91


D21
3.99
3.01
2.51





D23
17.01
23.94
35.52










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
66.25



Second lens group
4
−13.76



Third lens group
10
15.90



Fourth lens group
20
−15.48



Fifth lens group
22
37.44










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 2.022


Conditional expression(JK2) (−fXn)/fM = 0.865


Conditional expression(JK3) dAB/|fF| = 0.061


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.162


Conditional expression(JM2) |fF|/fM = 2.022


Conditional expression(JM3) dAB/|fF| = 0.061


Conditional expression(JM4) (−fXn)/fM = 0.865


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 2.022


Conditional expression(JN2) dV/|fV| = 0.162


Conditional expression(JN3) dAB/|fF| = 0.061


Conditional expression(JN4) (−fXn)/fM = 0.865


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 26 that the zoom optical system ZL26 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 27
Example 27 is described with reference to FIG. 33 and Table 27. A zoom optical system ZLII (ZL27) according to Example 27 includes, as illustrated in FIG. 33, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having a concave surface facing the object side; the positive meniscus lens L34 having a convex surface facing the image side; and the negative meniscus lens L35 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes a positive meniscus lens L36 having a convex surface facing the object side. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases and then increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 27, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.149 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.153 mm when the correction angle is 0.519°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.142 mm when the correction angle is 0.387°.
In Table 27 below, specification values in Example are listed. Surface numbers 1 to 25 in Table 27 respectively correspond to the optical surfaces m1 to m25 in FIG. 33.







TABLE 27







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
33.8994
1.40
17.98
1.94594


2
27.5398
6.01
52.33
1.75500


3
126.6471
 D3(variable)




4
92.3727
1.00
40.66
1.88300


5
9.6821
6.44




*6
−23.7193
1.10
40.10
1.85135


*7
−83.8988
0.10




8
89.2398
1.85
17.98
1.94594


9
−53.5878
 D9(variable)




*10
25.3700
1.50
54.04
1.72903


11
230.2228
1.80




12
∞
1.50
(aperture stop)



13
30.9780
6.02
70.32
1.48749


14
−10.4882
1.00
34.92
1.80100


15
−22.5902
0.93




*16
−14.7775
1.52
54.04
1.72903


17
−10.5863
0.10




18
22.5542
1.00
28.69
1.79504


19
13.5152
D19(variable)




20
13.1123
2.16
82.57
1.49782


21
348.8524
D21(variable)




*22
−197.6815
1.00
40.10
1.85135


*23
14.3470
D23(variable)




24
24.2369
2.60
32.18
1.67270


25
∞
D25(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−2.49546E−05
−5.89565E−07
 1.60407E−09
−1.06140E−10


7th surface
0.00
−5.60606E−05
−3.05064E−07
−5.86297E−09
 0.00000E+00


10th surface
0.00
−2.37796E−05
 5.72212E−08
−2.69510E−09
 0.00000E+00


16th surface
0.00
−1.20110E−04
 2.92716E−07
−8.67042E−09
 2.49045E−11


22nd surface
0.00
 1.11744E−04
−5.34712E−06
 1.11410E−07
−9.54835E−10


23rd surface
0.00
 6.73836E−05
−4.97046E−06
 1.05990E−07
−9.01623E−10










[Various data]


Zoom ratio 2.94













Wide angle

Telephoto




end
Intermediate
end






f
16.5~
26.9~
48.5



FNO
2.9~
3.4~
4.1



2ω
81.7~
55.8~
32.3



Y
12.5~
14.0~
14.3



TL(air)
77.6~
82.5~
98.0



BF(air)
17.0~
22.6~
34.6











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.5
26.9
48.5
16.5
26.9
48.5


D3
0.80
8.10
17.74





D9
13.14
5.41
0.80





D19
1.95
1.95
1.95
1.52
1.06
0.03


D21
2.56
2.73
1.00
2.99
3.62
2.92


D23
3.17
2.70
2.85





D25
17.00
22.63
34.64










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
63.70



Second lens group
4
−13.85



Third lens group
10
15.94



Fourth lens group
22
−15.68



Fifth lens group
24
36.03










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.713


Conditional expression(JK2) (−fXn)/fM = 0.869


Conditional expression(JK3) dAB/|fF| = 0.071


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 66.085


Conditional expression(JL2) |fF|/fM = 1.713


Conditional expression(JL3) dAB/|fF| = 0.071


Conditional expression(JL4) (−fXn)/fM = 0.869


Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JL6) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.182


Conditional expression(JM2) |fF|/fM = 1.713


Conditional expression(JM3) dAB/|fF| = 0.071


Conditional expression(JM4) (−fXn)/fM = 0.869


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 1.713


Conditional expression(JN2) dV/|fV| = 0.182


Conditional expression(JN3) dAB/|fF| = 0.071


Conditional expression(JN4) (−fXn)/fM = 0.869


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 27 that the zoom optical system ZL27 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 28
Example 28 is described with reference to FIG. 34 and Table 28. A zoom optical system ZLII (ZL28) according to Example 28 includes, as illustrated in FIG. 34, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the biconvex lens L31; the aperture stop S; the cemented lens including the positive meniscus lens L32 having a convex surface facing the image side and the negative meniscus lens L33 having a concave surface facing the object side; the positive meniscus lens L34 having a convex surface facing the image side; and the negative meniscus lens L35 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes a biconvex lens L36. The biconvex lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases and then decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases and then increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 28, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.143 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.144 mm when the correction angle is 0.519°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.144 mm when the correction angle is 0.387°.
In Table 28 below, specification values in Example are listed. Surface numbers 1 to 25 in Table 28 respectively correspond to the optical surfaces m1 to m25 in FIG. 34.







TABLE 28







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
37.6690
1.40
17.98
1.94594


2
30.7768
5.49
52.33
1.75500


3
153.0002
 D3(variable)




4
105.2565
1.00
40.66
1.88300


5
10.1696
7.24




*6
−20.8194
1.10
40.10
1.85135


*7
−52.3791
0.10




8
1331.6674
1.74
17.98
1.94594


9
−40.6822
 D9(variable)




*10
23.8959
2.11
54.04
1.72903


11
−42.1515
1.80




12
∞
1.50
(aperture stop)



13
−361.9871
3.86
70.32
1.48749


14
−8.7743
1.00
34.92
1.80100


15
−11.3715
0.10




*16
−21.9272
0.95
54.04
1.72903


17
−24.9045
0.10




18
21.1771
1.00
28.69
1.79504


19
9.8802
D19(variable)




20
12.1120
2.81
82.57
1.49782


21
−70.6477
D21(variable)




*22
−6109.2098
1.00
40.10
1.85135


*23
12.6136
D23(variable)




24
23.1959
2.53
32.18
1.67270


25
∞
D25(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−4.88185E−05
 2.75927E−08
−3.15364E−09
−7.98095E−11


7th surface
0.00
−7.62891E−05
 2.27328E−07
−8.08982E−09
 0.00000E+00


10th surface
0.00
−7.94822E−05
−3.39871E−08
−6.07178E−09
 0.00000E+00


16th surface
0.00
−3.91116E−05
 3.34980E−07
−1.57304E−09
 1.71741E−11


22nd surface
0.00
 7.48094E−05
−2.63577E−06
 6.19261E−08
−5.37903E−10


23rd surface
0.00
 3.43492E−05
−2.41206E−06
 5.49617E−08
−3.93573E−10










[Various data]


Zoom ratio 2.94













Wide

Telephoto




angle end
Intermediate
end






f
16.5~
27.0~
48.5



FNO
2.9~
3.4~
4.1



2ω
81.7~
55.7~
32.5



Y
12.5~
13.9~
14.3



TL(air)
77.7~
82.5~
98.0



BF(air)
17.0~
22.9~
31.9











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide

Telephoto
Wide

Telephoto



angle end
Intermediate
end
angle end
Intermediate
end





f
16.5
27.0
48.5
16.5
27.0
48.5


D3
0.80
7.52
18.90





D9
14.16
5.88
0.80





D19
5.41
5.41
5.41
5.02
4.62
3.60


D21
0.87
1.48
1.00
1.27
2.27
2.82


D23
2.64
2.49
3.14





D25
17.00
22.88
31.90










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
69.12



Second lens group
4
−13.69



Third lens group
10
17.00



Fourth lens group
22
−14.78



Fifth lens group
24
34.48










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.416


Conditional expression(JK2) (−fXn)/fM = 0.923


Conditional expression(JK3) dAB/|fF| = 0.258


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 9.854


Conditional expression(JL2) |fF|/fM = 1.416


Conditional expression(JL3) dAB/|fF| = 0.258


Conditional expression(JL4) (−fXn)/fM = 0.923


Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JL6) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.212


Conditional expression(JM2) |fF|/fM = 1.416


Conditional expression(JM3) dAB/|fF| = 0.258


Conditional expression(JM4) (−fXn)/fM = 0.923


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 1.416


Conditional expression(JN2) dV/|fV| = 0.212


Conditional expression(JN3) dAB/|fF| = 0.258


Conditional expression(JN4) (−fXn)/fM = 0.923


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 28 that the zoom optical system ZL28 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 29
Example 29 is described with reference to FIG. 35 and Table 29. A zoom optical system ZLII (ZL29) according to Example 29 includes, as illustrated in FIG. 35, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having a concave surface facing the object side; a biconcave lens L34; and the negative meniscus lens L35 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the biconvex lens L36. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The biconcave lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases and then decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases and then increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 29, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.119 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.117 mm when the correction angle is 0.520°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.120 mm when the correction angle is 0.387°.
In Table 29 below, specification values in Example are listed. Surface numbers 1 to 25 in Table 29 respectively correspond to the optical surfaces m1 to m25 in FIG. 35.







TABLE 29







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
35.9311
1.40
17.98
1.94594


2
29.3530
5.87
52.33
1.75500


3
144.9525
 D3(variable)




4
90.5280
1.00
40.66
1.88300


5
9.9424
6.38




*6
−24.8978
1.10
40.10
1.85135


*7
−109.2593
0.10




8
72.2923
1.85
17.98
1.94594


9
−64.1394
 D9(variable)




*10
22.0322
1.46
54.04
1.72903


11
78.6588
1.80




12
∞
1.50
(aperture stop)



13
39.3804
7.28
70.32
1.48749


14
−8.3594
1.00
34.92
1.80100


15
−10.9912
0.10




*16
−1463.0009
0.90
54.04
1.72903


17
399.2118
0.10




18
29.7363
1.00
28.69
1.79504


19
14.1659
D19(variable)




20
12.0460
2.69
67.90
1.59319


21
−161.5248
D21(variable)




*22
−112.0734
1.00
40.10
1.85135


*23
12.0674
D23(variable)




24
25.4959
2.47
32.18
1.67270


25
∞
D25(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−4.90680E−05
−2.96114E−07
 1.23159E−09
−1.00914E−10


7th surface
0.00
−7.33376E−05
−3.11275E−09
−6.22074E−09
 0.00000E+00


10th surface
0.00
−4.70151E−05
−2.47124E−08
−8.76074E−09
 0.00000E+00


16th surface
0.00
−1.00072E−04
−6.68495E−08
−6.27648E−11
 1.61473E−12


22nd surface
0.00
 9.60313E−05
−3.64209E−06
 6.01110E−08
−4.07929E−10


23rd surface
0.00
 2.02167E−05
−3.49227E−06
 6.09640E−08
−3.91518E−10










[Various data]


Zoom ratio 2.94













Wide

Telephoto




angle end
Intermediate
end






f
16.5~
26.9~
48.5



FNO
2.9~
3.5~
4.1



2ω
81.7~
55.9~
32.5



Y
12.5~
13.9~
14.3



TL(air)
77.1~
80.8~
98.0



BF(air)
16.7~
24.1~
32.9











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide

Telephoto
Wide

Telephoto



angle end
Intermediate
end
angle end
Intermediate
end





f
16.5
26.9
48.5
16.5
26.9
48.5


D3
0.80
5.95
18.25





D9
13.15
4.94
0.80





D19
1.82
1.82
1.82
1.54
1.29
0.61


D21
1.65
1.75
1.00
1.93
2.28
2.21


D23
3.73
3.21
4.27





D25
17.00
24.11
32.86










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
65.87



Second lens group
4
−13.88



Third lens group
10
14.23



Fourth lens group
22
−12.75



Fifth lens group
24
37.90










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.336


Conditional expression(JK2) (−fXn)/fM = 0.976


Conditional expression(JK3) dAB/|fF| = 0.096


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JK5) νdp = 67.90


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 12.364


Conditional expression(JL2) |fF|/fM = 1.336


Conditional expression(JL3) dAB/|fF| = 0.096


Conditional expression(JL4) (−fXn)/fM = 0.976


Conditional expression(JL5) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JL6) νdp = 67.90


Conditional expression(JM1) dV/|fV| = 0.335


Conditional expression(JM2) |fF|/fM = 1.336


Conditional expression(JM3) dAB/|fF| = 0.096


Conditional expression(JM4) (−fXn)/fM = 0.976


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JM6) νdp = 67.90


Conditional expression(JN1) |fF|/fM = 1.336


Conditional expression(JN2) dV/|fV| = 0.335


Conditional expression(JN3) dAB/|fF| = 0.096


Conditional expression(JN4) (−fXn)/fM = 0.976


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.073


Conditional expression(JN6) νdp = 67.90









It can be seen in Table 29 that the zoom optical system ZL29 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JL1) to (JL6), (JM1) to (JM6), and (JN1) to (JN6).
Example 30
Example 30 is described with reference to FIG. 36 and Table 30. A zoom optical system ZLII (ZL30) according to Example 30 includes, as illustrated in FIG. 36, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and a biconcave lens L33; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the positive meniscus lens L35 having a convex surface facing the object side. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases and then decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases and then increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 30, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.149 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.148 mm when the correction angle is 0.472°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.138 mm when the correction angle is 0.369°.
In Table 30 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 30 respectively correspond to the optical surfaces m1 to m23 in FIG. 36.







TABLE 30







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
39.2657
1.40
17.98
1.94594


2
32.0347
5.41
54.61
1.72916


3
212.2782
 D3(variable)




4
98.5206
1.00
40.66
1.88300


5
10.2718
5.76




*6
−28.7616
1.10
40.10
1.85135


*7
−227.7422
0.10




8
43.7706
1.81
17.98
1.94594


9
−144.7057
 D9(variable)




*10
18.8952
1.81
40.10
1.85135


11
174.2175
1.80




12
∞
1.50
(aperture stop)



13
37.6452
4.77
82.57
1.49782


14
−12.1742
1.00
28.69
1.79504


15
109.6975
1.86




*16
−23.7259
2.77
61.25
1.58913


17
−10.9579
D17(variable)




18
14.9105
1.96
82.57
1.49782


19
126.8885
D19(variable)




*20
−104.1893
1.00
40.10
1.85135


*21
14.8854
D21(variable)




22
25.1236
2.47
27.57
1.75520


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−4.72972E−05
−5.73102E−07
2.68294E−09
−3.91891E−11


7th surface
0.00
−6.48435E−05
−3.58350E−07
−2.56642E−10
 0.00000E+00


10th surface
0.00
−3.56816E−06
 2.00247E−08
 4.46645E−10
 0.00000E+00


16th surface
0.00
−1.64136E−04
 3.66711E−07
−1.61799E−08
 1.14197E−10


20th surface
0.00
 8.65735E−05
−3.88224E−06
 7.16573E−08
−5.59042E−10


21st surface
0.00
 4.14922E−05
−3.47282E−06
 6.38155E−08
−4.78441E−10










[Various data]


Zoom ratio 3.24













Wide

Telephoto




angle end
Intermediate
end






f
16.5~
32.6~
53.4



FNO
2.9~
3.5~
4.1



2ω
81.7~
46.9~
29.1



Y
12.4~
14.3~
14.3



TL(air)
76.5~
85.0~
102.0



BF(air)
17.0~
25.9~
37.1











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide

Telephoto
Wide

Telephoto



angle end
Intermediate
end
angle end
Intermediate
end





f
16.5
32.6
53.4
16.5
32.6
53.4


D3
0.80
10.93
21.12





D9
13.98
3.53
0.80





D17
2.10
2.10
2.10
1.58
0.78
0.06


D19
2.56
2.94
1.00
3.08
4.26
3.04


D21
2.54
2.07
2.41





D23
17.00
25.92
37.06










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
70.16



Second lens group
4
−14.24



Third lens group
10
16.74



Fourth lens group
20
−15.24



Fifth lens group
22
33.27










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 2.016


Conditional expression(JK2) (−fXn)/fM = 0.850


Conditional expression(JK3) dAB/|fF| = 0.062


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.158


Conditional expression(JM2) |fF|/fM = 2.016


Conditional expression(JM3) dAB/|fF| = 0.062


Conditional expression(JM4) (−fXn)/fM = 0.850


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 2.016


Conditional expression(JN2) dV/|fV| = 0.158


Conditional expression(JN3) dAB/|fF| = 0.062


Conditional expression(JN4) (−fXn)/fM = 0.850


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 30 that the zoom optical system ZL30 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 31
Example 31 is described with reference to FIG. 37 and Table 31. A zoom optical system ZLII (ZL31) according to Example 31 includes, as illustrated in FIG. 37, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, and the fourth lens group G4 having negative refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the biconcave lens L33; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the positive meniscus lens L35 having a convex surface facing the object side. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41 and the plano-convex lens L42 having a convex surface facing the object side that are arranged in order from the object side. The biconcave lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3 and the fourth lens group G4 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, and the distance between the third lens group G3 and the fourth lens group G4 increases and then decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the biconcave lens L41 forming the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 31, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.157 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.162 mm when the correction angle is 0.472°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.146 mm when the correction angle is 0.369°.
In Table 31 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 31 respectively correspond to the optical surfaces m1 to m23 in FIG. 37.







TABLE 31







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
37.2595
1.40
17.98
1.94594


2
30.3215
5.43
54.61
1.72916


3
191.3214
 D3(variable)




4
134.9736
1.00
40.66
1.88300


5
10.2676
5.70




*6
−32.2878
1.10
40.10
1.85135


*7
−249.3634
0.10




8
43.7941
1.80
17.98
1.94594


9
−160.6246
 D9(variable)




*10
18.8735
1.78
40.10
1.85135


11
132.0272
1.80




12
∞
1.50
(aperture stop)



13
32.7740
4.92
82.57
1.49782


14
−12.5016
1.00
28.69
1.79504


15
92.7101
1.79




*16
−22.1018
2.82
61.25
1.58913


17
−10.8359
D17(variable)




18
15.4516
1.92
82.57
1.49782


19
126.0321
D19(variable)




*20
−104.9496
1.00
40.10
1.85135


*21
15.5828
2.05




22
25.3403
2.30
27.57
1.75520


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−4.17899E−05
−4.91408E−07
 1.22049E−09
−4.60622E−11


7th surface
0.00
−6.39202E−05
−3.13505E−07
−2.48667E−09
 0.00000E+00


10th surface
0.00
−3.22843E−06
 3.45613E−08
 1.52095E−10
 0.00000E+00


16th surface
0.00
−1.67711E−04
 3.82028E−07
−1.87748E−08
 1.37248E−10


20th surface
0.00
 8.68143E−05
−3.88707E−06
 6.90451E−08
−5.08312E−10


21st surface
0.00
 4.57778E−05
−3.40999E−06
 5.93726E−08
−4.04483E−10










[Various data]


Zoom ratio 3.24













Wide

Telephoto




angle end
Intermediate
end






f
16.5~
32.5~
53.4



FNO
2.9~
3.5~
4.3



2ω
81.7~
47.0~
29.1



Y
12.4~
14.3~
14.3



TL(air)
93.4~
110.9~
137.4



BF(air)
17.0~
24.4~
36.3











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide

Telephoto
Wide

Telephoto



angle end
Intermediate
end
angle end
Intermediate
end





f
16.5
32.5
53.4
16.5
32.5
53.4


D3
0.80
11.80
20.57





D9
14.21
3.89
0.80





D17
2.21
2.21
2.21
1.65
0.73
0.50


D19
2.80
3.25
1.00
3.36
4.73
2.71


D23
17.00
24.44
36.31










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
67.35



Second lens group
4
−14.35



Third lens group
10
17.12



Fourth lens group
20
−34.24










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 2.055


Conditional expression(JK2) (−fXn)/fM = 0.838


Conditional expression(JK3) dAB/|fF| = 0.063


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.129


Conditional expression(JM2) |fF|/fM = 2.055


Conditional expression(JM3) dAB/|fF| = 0.063


Conditional expression(JM4) (−fXn)/fM = 0.838


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57









It can be seen in Table 31 that the zoom optical system ZL31 according to this Example satisfies the conditional expression (JK1) to (JK5) and (JM1) to (JM6).
Example 32
Example 32 is described with reference to FIG. 38 and Table 32. A zoom optical system ZLII (ZL32) according to Example 32 includes, as illustrated in FIG. 38, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the biconvex lens L31; the aperture stop S; the cemented lens including the biconvex lens L32 and the biconcave lens L33; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the positive meniscus lens L35 having a convex surface facing the object side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases and then decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases and then increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 32, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.189 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.190 mm when the correction angle is 0.426°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.145 mm when the correction angle is 0.327°.
In Table 32 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 32 respectively correspond to the optical surfaces m1 to m23 in FIG. 38.







TABLE 32







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
45.8874
1.50
17.98
1.94594


2
37.3615
5.50
52.34
1.75500


3
323.7680
 D3(variable)




4
140.8508
1.00
40.66
1.88300


5
11.0397
6.53




*6
−21.1084
1.00
52.19
1.73878


*7
−98.9946
0.10




8
70.2805
1.69
17.98
1.94594


9
−92.1974
 D9(variable)




*10
22.5197
4.22
47.98
1.76169


*11
−78.0166
1.80




12
∞
1.50
(aperture stop)



13
49.1316
5.00
82.57
1.49782


14
−13.1671
1.00
32.35
1.85026


15
101.7221
2.56




*16
−61.2541
2.57
69.31
1.57174


17
−13.4270
D17(variable)




18
18.2771
2.04
82.57
1.49782


19
119.6079
D19(variable)




20
−162.3503
1.00
40.10
1.85135


*21
17.4138
D21(variable)




22
31.4780
3.05
27.57
1.75520


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−6.56786E−05
−6.01492E−07
 8.47437E−09
−8.17300E−11


7th surface
0.00
−8.13714E−05
−8.69532E−08
 2.87236E−10
 0.00000E+00


10th surface
0.00
−1.46882E−05
 2.47912E−07
−4.38965E−09
 0.00000E+00


11th surface
0.00
−3.21954E−06
 2.40618E−07
−5.20291E−09
 0.00000E+00


16th surface
0.00
−7.48031E−05
 2.72716E−07
−7.00743E−09
 4.39288E−11


21st surface
0.00
−2.40674E−05
 1.83152E−07
−4.07579E−09
 3.04708E−11










[Various data]


Zoom ratio 4.13













Wide

Telephoto




angle end
Intermediate
end






f
16.5~
40.1~
68.0



FNO
2.9~
3.9~
4.3



2ω
81.7~
38.5~
23.2



Y
12.2~
14.3~
14.3



TL(air)
83.5~
97.7~
125.5



BF(air)
13.0~
25.7~
48.7











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide

Telephoto
Wide

Telephoto



angle end
Intermediate
end
angle end
Intermediate
end





f
16.5
40.1
68.0
16.5
40.1
68.0


D3
0.80
15.31
25.34





D9
15.08
1.96
0.80





D17
2.49
2.49
2.49
1.85
0.24
0.10


D19
4.08
6.04
1.00
4.73
8.29
3.39


D21
5.98
4.11
5.16





D23
13.00
25.69
48.66










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
74.60



Second lens group
4
−13.20



Third lens group
10
18.68



Fourth lens group
20
−18.43



Fifth lens group
22
41.68










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 2.304


Conditional expression(JK2) (−fXn)/fM = 0.707


Conditional expression(JK3) dAB/|fF| = 0.058


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.280


Conditional expression(JM2) |fF|/fM = 2.304


Conditional expression(JM3) dAB/|fF| = 0.058


Conditional expression(JM4) (−fXn)/fM = 0.707


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 2.304


Conditional expression(JN2) dV/|fV| = 0.280


Conditional expression(JN3) dAB/|fF| = 0.058


Conditional expression(JN4) (−fXn)/fM = 0.707


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 32 that the zoom optical system ZL32 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 33
Example 33 is described with reference to FIG. 39 and Table 33. A zoom optical system ZLII (ZL33) according to Example 33 includes, as illustrated in FIG. 39, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, and the positive meniscus lens L23 having a convex surface facing the object side that are arranged in order from the object side. The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having the concave surface facing the object side; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the biconvex lens L35. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 33, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.129 mm when the correction angle is 0.767°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.114 mm when the correction angle is 0.536°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.116 mm when the correction angle is 0.422°.
In Table 33 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 33 respectively correspond to the optical surfaces m1 to m23 in FIG. 39.







TABLE 33







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
42.6649
1.50
17.98
1.94594


2
33.9782
4.33
46.60
1.80400


3
159.3713
 D3(variable)




4
231.5864
1.00
40.66
1.88300


5
9.6693
4.88




*6
−144.6832
1.00
40.10
1.85135


*7
64.0000
0.43




8
27.6064
1.87
17.98
1.94594


9
180.3050
 D9(variable)




*10
18.1446
1.36
40.10
1.85135


11
36.2222
1.80




12
∞
1.50
(aperture stop)



13
30.5754
4.65
82.57
1.49782


14
−19.8920
0.90
25.45
1.80518


15
−2398.7427
1.33




*16
−16.4870
2.00
67.02
1.59201


17
−9.3211
D17(variable)




18
16.0663
1.92
82.57
1.49782


19
−92.5945
D19(variable)




*20
−129.7857
1.00
40.10
1.85135


*21
13.7524
D21(variable)




22
24.7189
1.70
30.13
1.69895


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
 7.24202E−05
−3.04361E−07
−7.53193E−09
0.00000E+00


7th surface
0.00
 3.00588E−05
−4.27011E−07
−1.14290E−08
0.00000E+00


10th surface
0.00
−2.81460E−05
 9.76630E−08
−7.99018E−09
0.00000E+00


16th surface
0.00
−2.41098E−04
 1.15336E−07
−7.22175E−09
−1.23487E−11 


20th surface
0.00
 1.00855E−04
−2.22406E−06
−9.91620E−09
4.72846E−10


21st surface
0.00
 1.24785E−05
−1.73565E−06
−3.98232E−09
3.04446E−10










[Various data]


Zoom ratio 3.30













Wide

Telephoto




angle end
Intermediate
end






f
12.4~
25.3~
40.8



FNO
2.9~
3.6~
4.2



2ω
82.3~
46.3~
29.7



Y
9.3~
10.5~
10.8



TL(air)
73.3~
80.5~
95.0



BF(air)
17.0~
28.8~
37.0











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide

Telephoto
Wide

Telephoto



angle end
Intermediate
end
angle end
Intermediate
end





f
12.4
25.3
40.8
12.4
25.3
40.8


D3
0.80
7.95
18.34





D9
16.98
4.97
0.80





D17
1.76
1.76
1.76
1.32
0.71
0.26


D19
2.24
1.48
1.00
2.68
2.53
2.50


D21
1.36
2.31
2.98





D23
17.00
28.84
36.97










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
75.04



Second lens group
4
−14.01



Third lens group
10
14.43



Fourth lens group
20
−14.56



Fifth lens group
22
35.37










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.917


Conditional expression(JK2) (−fXn)/fM = 0.971


Conditional expression(JK3) dAB/|fF| = 0.064


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.205


Conditional expression(JM2) |fF|/fM = 1.917


Conditional expression(JM3) dAB/|fF| = 0.064


Conditional expression(JM4) (−fXn)/fM = 0.971


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 1.917


Conditional expression(JN2) dV/|fV| = 0.205


Conditional expression(JN3) dAB/|fF| = 0.064


Conditional expression(JN4) (−fXn)/fM = 0.971


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 33 that the zoom optical system ZL33 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 34
Example 34 is described with reference to FIG. 40 and Table 34. A zoom optical system ZLII (ZL34) according to Example 34 includes, as illustrated in FIG. 40, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, and the positive meniscus lens L23 having a convex surface facing the object side that are arranged in order from the object side. The biconcave lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having a concave surface facing the object side; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the cemented lens including the negative meniscus lens L35 having a concave surface facing the image side, and the biconvex lens L36. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, and the fifth lens group G5 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 34, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.117 mm when the correction angle is 0.767°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.103 mm when the correction angle is 0.536°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.109 mm when the correction angle is 0.422°.
In Table 34 below, specification values in Example are listed. Surface numbers 1 to 24 in Table 34 respectively correspond to the optical surfaces m1 to m24 in FIG. 40.







TABLE 34







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
41.0387
1.50
17.98
1.94594


2
33.2111
4.39
46.60
1.80400


3
167.0985
 D3(variable)




4
521.1609
1.00
42.73
1.83481


5
9.2341
4.89




*6
−500.5038
1.00
40.10
1.85135


*7
55.5356
0.49




8
29.8211
1.80
17.98
1.94594


9
240.2636
 D9(variable)




*10
43.0468
1.08
40.10
1.85135


11
298.9859
1.80




12
∞
1.50
(aperture stop)



13
882.4766
2.44
82.57
1.49782


14
−12.8062
0.90
39.61
1.80440


15
−48.5711
0.50




*16
−45.5329
2.17
61.25
1.58913


17
−10.8642
D17(variable)




18
23.6501
0.85
25.45
1.80518


19
16.9311
2.87
82.57
1.49782


20
−20.3779
D20(variable)




*21
−4198.2163
0.90
40.10
1.85135


*22
11.8449
D22(variable)




23
28.5733
1.70
30.13
1.69895


24
∞
D24(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
 7.53002E−05
 2.66920E−07
−1.57255E−08
0.00000E+00


7th surface
0.00
 3.00588E−05
 5.32743E−08
−2.15009E−08
0.00000E+00


10th surface
0.00
−5.13064E−05
−8.94237E−08
−1.30090E−08
0.00000E+00


16th surface
0.00
−1.89235E−04
 5.82030E−07
 4.84663E−09
−3.16900E−11 


21st surface
0.00
 1.05691E−04
−1.83434E−06
−1.41531E−08
3.60695E−10


22nd surface
0.00
 6.69976E−06
−2.04472E−06
−1.53304E−08
3.78430E−10










[Various data]


Zoom ratio 3.30













Wide angle

Telephoto




end
Intermediate
end






f
12.4~
25.3~
40.8



FNO
2.9~
3.9~
4.1



2ω
82.3~
46.2~
29.6



Y
9.3~
10.6~
10.8



TL(air)
71.9~
79.1~
93.6



BF(air)
17.0~
30.0~
37.0











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
12.4
25.3
40.8
12.4
25.3
40.8


D3
0.80
6.10
17.49





D9
16.46
4.29
0.80





D17
1.62
1.62
1.62
1.28
0.81
0.43


D20
2.32
1.49
1.00
2.66
2.30
2.19


D22
2.81
3.27
5.34





D24
17.00
30.01
36.96










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
69.70



Second lens group
4
−14.01



Third lens group
10
12.79



Fourth lens group
21
−13.87



Fifth lens group
23
40.88










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.982


Conditional expression(JK2) (−fXn)/fM = 1.096


Conditional expression(JK3) dAB/|fF| = 0.064


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.385


Conditional expression(JM2) |fF|/fM = 1.982


Conditional expression(JM3) dAB/|fF| = 0.064


Conditional expression(JM4) (−fXn)/fM = 1.096


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 1.982


Conditional expression(JN2) dV/|fV| = 0.385


Conditional expression(JN3) dAB/|fF| = 0.064


Conditional expression(JN4) (−fXn)/fM = 1.096


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 34 that the zoom optical system ZL34 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 35
Example 35 is described with reference to FIG. 41 and Table 35. A zoom optical system ZLII (ZL35) according to Example 35 includes, as illustrated in FIG. 41, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the image side, and the positive meniscus lens L23 having a convex surface facing the object side that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having a concave surface facing the object side; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the biconvex lens L35. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 35, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.090 mm when the correction angle is 0.657°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.074 mm when the correction angle is 0.434°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.072 mm when the correction angle is 0.339°.
In Table 35 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 35 respectively correspond to the optical surfaces m1 to m23 in FIG. 41.







TABLE 35







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
51.0809
1.50
17.98
1.94594


2
46.4942
2.93
46.60
1.80400


3
228.7461
 D3(variable)




4
70.0563
1.00
40.66
1.88300


5
9.1493
4.76




*6
259.1277
1.00
40.10
1.85135


*7
28.4168
0.37




8
16.9265
1.91
17.98
1.94594


9
37.6302
 D9(variable)




*10
16.1146
0.91
45.45
1.80139


11
21.7610
1.80




12
∞
1.50
(aperture stop)



13
46.3877
2.56
82.57
1.49782


14
−14.0243
0.90
23.78
1.84666


15
−30.1385
0.55




*16
−27.4566
1.89
58.16
1.62263


17
−9.4604
D17(variable)




18
17.7225
1.57
82.57
1.49782


19
−130.4521
D19(variable)




*20
−330.7048
1.00
40.10
1.85135


*21
11.0749
D21(variable)




22
26.2408
1.51
30.13
1.69895


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
 4.58823E−05
−6.02477E−07
 1.64703E−09
0.00000E+00


7th surface
0.00
 3.00588E−05
−5.71646E−07
−1.87171E−09
0.00000E+00


10th surface
0.00
−1.14380E−04
−2.04290E−07
−5.40507E−08
0.00000E+00


16th surface
0.00
−2.20534E−04
 6.27017E−07
 1.51567E−08
−1.50349E−10 


20th surface
0.00
 8.78409E−05
−1.44739E−06
−9.85122E−08
1.92159E−09


21st surface
0.00
−4.65898E−05
−1.28759E−06
−9.81776E−08
1.84980E−09










[Various data]


Zoom ratio 3.75













Wide angle

Telephoto




end
Intermediate
end






f
9.3~
21.3~
34.8



FNO
2.9~
3.9~
4.3



2ω
81.3~
41.0~
25.8



Y
6.9~
7.8~
7.9



TL(air)
65.6~
68.4~
87.0



BF(air)
13.0~
25.6~
34.6











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
9.3
21.3
34.8
9.3
21.3
34.8


D3
0.80
4.82
15.65





D9
18.19
4.27
0.80





D17
2.22
2.22
2.22
1.79
1.15
0.89


D19
2.22
1.46
1.00
2.64
2.53
2.33


D21
1.52
2.34
5.10





D23
13.00
25.64
34.57










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
82.42



Second lens group
4
−12.96



Third lens group
10
11.56



Fourth lens group
20
−12.57



Fifth lens group
22
37.54










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 2.722


Conditional expression(JK2) (−fXn)/fM = 1.121


Conditional expression(JK3) dAB/|fF| = 0.071


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.406


Conditional expression(JM2) |fF|/fM = 2.722


Conditional expression(JM3) dAB/|fF| = 0.071


Conditional expression(JM4) (−fXn)/fM = 1.121


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 2.722


Conditional expression(JN2) dV/|fV| = 0.406


Conditional expression(JN3) dAB/|fF| = 0.071


Conditional expression(JN4) (−fXn)/fM = 1.121


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 35 that the zoom optical system ZL35 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 36
Example 36 is described with reference to FIG. 42 and Table 36. A zoom optical system ZLII (ZL36) according to Example 36 includes, as illustrated in FIG. 42, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, and the fifth lens group G5 having negative refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having negative refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having a concave surface facing the object side; and the negative meniscus lens L34 having a concave surface facing the image side that are arranged in order from the object side. The image side group GB includes the negative meniscus lens L35 having a concave surface facing the image side. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The negative meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the biconvex lens L41.
The fifth lens group G5 includes the biconcave lens L51 and the plano-convex lens L52 having a convex surface facing the object side that are arranged in order from the object side. The biconcave lens L51 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 each moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the image side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the biconcave lens L51 forming the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 36, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.185 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.186 mm when the correction angle is 0.520°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.183 mm when the correction angle is 0.387°.
In Table 36 below, specification values in Example are listed. Surface numbers 1 to 25 in Table 36 respectively correspond to the optical surfaces m1 to m25 in FIG. 42.







TABLE 36







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
31.3787
1.40
17.98
1.94594


2
25.8482
5.59
52.33
1.75500


3
88.0110
 D3(variable)




4
94.0313
1.00
40.66
1.88300


5
9.7840
6.32




*6
−34.5984
1.10
42.71
1.82080


*7
−460.7224
1.11




8
98.7113
1.76
17.98
1.94594


9
−64.5703
 D9(variable)




*10
17.7201
1.45
54.04
1.72903


11
34.5176
1.80




12
∞
1.50
(aperture stop)



13
17.3794
6.43
82.57
1.49782


14
−11.9300
1.00
23.78
1.84666


15
−14.0311
0.12




*16
500.8042
0.90
40.10
1.85135


17
47.8924
D17(variable)




18
61.4713
1.00
67.90
1.59319


19
16.3627
D19(variable)




20
17.9950
2.28
82.57
1.49782


21
−59.3167
D21(variable)




*22
−90.4295
1.00
24.06
1.82115


*23
19.2966
3.17




24
33.0683
2.03
22.74
1.80809


25
∞
D25(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−7.02036E−05
−2.95397E−08
 2.81097E−10
−1.35280E−10


7th surface
0.00
−1.08565E−04
 3.26827E−07
−1.15001E−08
 0.00000E+00


10th surface
0.00
−3.45329E−05
 9.24026E−08
−8.23372E−09
 0.00000E+00


16th surface
0.00
−1.10206E−04
−2.93723E−07
−1.23313E−09
−3.17553E−11


22nd surface
0.00
 7.03563E−05
−3.25833E−06
 5.59796E−08
−4.39781E−10


23rd surface
0.00
 4.73428E−05
−2.90162E−06
 4.80962E−08
−3.49905E−10










[Various data]


Zoom ratio 2.94













Wide angle

Telephoto




end
Intermediate
end






f
16.5~
26.8~
48.5



FNO
2.9~
3.6~
4.1



2ω
81.7~
58.3~
33.0



Y
12.5~
13.6~
14.1



TL(air)
77.7~
81.3~
98.0



BF(air)
17.0~
22.8~
32.9











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.5
26.8
48.5
16.5
26.8
48.5


D3
0.80
5.86
18.37





D9
13.94
5.21
0.80





D17
0.40
0.40
0.40
1.38
2.52
3.85


D19
2.22
3.12
3.54
1.24
1.00
0.08


D21
2.41
2.95
1.00





D25
17.00
22.82
32.93










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
66.00



Second lens group
4
−14.12



Third lens group
10
23.82



Fourth lens group
20
28.01



Fifth lens group
22
−42.97










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.591


Conditional expression(JK2) (−fXn)/fM = 0.593


Conditional expression(JK3) dAB/|fF| = 0.093


Conditional expression(JK6) ndn + 0.0075 × νdn − 2.175 = −0.073


Conditional expression(JK7) νdn = 67.90


Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 21.049


Conditional expression(JL2) |fF|/fM = 1.591


Conditional expression(JL3) dAB/|fF| = 0.093


Conditional expression(JL4) (−fXn)/fM = 0.593


Conditional expression(JL7) ndn + 0.0075 × νdn − 2.175 = −0.073


Conditional expression(JL8) νdn = 67.90


Conditional expression(JM1) dV/|fV| = 0.164


Conditional expression(JM2) |fF|/fM = 1.591


Conditional expression(JM3) dAB/|fF| = 0.093


Conditional expression(JM4) (−fXn)/fM = 0.593


Conditional expression(JM7) ndn + 0.0075 × νdn − 2.175 = −0.073


Conditional expression(JM8) νdn = 67.90


Conditional expression(JN1) |fF|/fM = 1.591


Conditional expression(JN2) dV/|fV| = 0.164


Conditional expression(JN3) dAB/|fF| = 0.093


Conditional expression(JN4) (−fXn)/fM = 0.593


Conditional expression(JN7) ndn + 0.0075 × νdn − 2.175 = −0.073


Conditional expression(JN8) νdn = 67.90









It can be seen in Table 36 that the zoom optical system ZL36 according to this Example satisfies the conditional expressions (JK1) to (JK3), (JK6), (JK7), (JL1) to (JL4), (JL7), (JL8), (JM1)to (JM4), (JM7), (JM8), (JN1) to (JN4), (JN7), and (JN8).
Example 37
Example 37 is described with reference to FIG. 43 and Table 37. A zoom optical system ZLII (ZL37) according to Example 37 includes, as illustrated in FIG. 43, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the image side, and the positive meniscus lens L23 having a convex surface facing the object side that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the negative meniscus lens L33 having a concave surface facing the object side; and the positive meniscus lens L34 having a convex surface facing the image side that are arranged in order from the object side. The image side group GB includes the positive meniscus lens L35 having a convex surface facing the object side. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The positive meniscus lens L34 is a glass-molded aspherical lens with a lens surface, on the image surface side, having an aspherical shape.
The fourth lens group G4 includes the biconcave lens L41. The biconcave lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, and the third lens group G3, the fourth lens group G4, and the fifth lens group G5 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 decreases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 37, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.071 mm when the correction angle is 0.657°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.062 mm when the correction angle is 0.433°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.060 mm when the correction angle is 0.339°.
In Table 37 below, specification values in Example are listed. Surface numbers 1 to 23 in Table 37 respectively correspond to the optical surfaces m1 to m23 in FIG. 43.







TABLE 37







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
53.1551
1.50
17.98
1.94594


2
46.7292
4.20
49.62
1.77250


3
282.4154
 D3(variable)




4
66.2821
1.00
40.66
1.88300


5
9.1032
4.68




*6
107.6212
1.00
40.10
1.85135


*7
22.7268
0.28




8
13.8002
2.03
17.98
1.94594


9
26.1074
 D9(variable)




*10
33.1702
0.71
45.45
1.80139


11
37.4535
1.80




12
∞
1.50
(aperture stop)



13
26.6043
3.68
70.32
1.48749


14
−8.5245
0.90
23.78
1.84666


15
−12.3206
0.10




16
−20.4613
1.76
59.46
1.58313


*17
−8.8729
D17(variable)




18
13.1305
1.32
82.57
1.49782


19
41.4579
D19(variable)




*20
−44.5994
1.00
40.10
1.85135


*21
10.7829
D21(variable)




22
25.6050
1.49
30.13
1.69895


23
∞
D23(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
3.49775E−05
 2.03744E−07
−3.87240E−09
0.00000E+00


7th surface
0.00
3.00588E−05
 4.54650E−07
−8.42603E−09
0.00000E+00


10th surface
0.00
−2.05375E−04 
−1.16277E−06
−6.81490E−08
0.00000E+00


17th surface
0.00
2.63944E−04
−2.28950E−06
 4.31206E−08
0.00000E+00


20th surface
0.00
3.75891E−04
−2.46541E−05
 6.07004E−07
−6.07981E−09 


21st surface
0.00
1.49191E−04
−2.01441E−05
 5.16615E−07
−5.33008E−09 










[Various data]


Zoom ratio 3.75













Wide angle

Telephoto




end
Intermediate
end






f
9.3~
21.3~
34.8



FNO
2.9~
4.3~
4.6



2ω
81.3~
41.0~
25.8



Y
6.9~
7.8~
8.0



TL(air)
65.9~
69.6~
86.2



BF(air)
13.0~
24.8~
33.7











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
9.3
21.3
34.8
9.3
21.3
34.8


D3
0.80
5.74
15.53





D9
17.51
4.34
0.80





D17
2.09
2.09
2.09
1.70
1.12
0.93


D19
1.65
1.23
1.00
2.05
2.20
2.16


D21
1.94
2.44
4.09





D23
13.00
24.85
33.70










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
86.74



Second lens group
4
−12.62



Third lens group
10
10.00



Fourth lens group
20
−10.12



Fifth lens group
22
36.63










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 3.800


Conditional expression(JK2) (−fXn)/fM = 1.262


Conditional expression(JK3) dAB/|fF| = 0.055


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 3.800


Conditional expression(JN2) dV/|fV| = 0.404


Conditional expression(JN3) dAB/|fF| = 0.055


Conditional expression(JN4) (−fXn)/fM = 1.262


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 37 that the zoom optical system ZL37 according to this Example satisfies the conditional expression (JK1) to (JK5) and (JN1) to (JN6).
Example 38
Example 38 is described with reference to FIG. 44 and Table 38. A zoom optical system ZLII (ZL38) according to Example 38 includes, as illustrated in FIG. 44, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having negative refractive power, and the fifth lens group G5 having positive refractive power that are arranged in order from the object side.
The first lens group G1 includes the cemented lens including the negative meniscus lens L11 having a concave surface facing the image side and the positive meniscus lens L12 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the negative meniscus lens L22 having a concave surface facing the object side, and the biconvex lens L23 that are arranged in order from the object side. The negative meniscus lens L22 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having positive refractive power that are arranged in order from the object side. The object side group GA includes: the positive meniscus lens L31 having a convex surface facing the object side; the aperture stop S; the cemented lens including the biconvex lens L32 and the biconcave lens L33; and the biconvex lens L34. The image side group GB includes the positive meniscus lens L35 having a convex surface facing the object side. The positive meniscus lens L31 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape. The biconvex lens L34 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fourth lens group G4 includes the negative meniscus lens L41 having a concave surface facing the image side and a positive meniscus lens L42 having a convex surface facing the object side that are arranged in order from the object side. The negative meniscus lens L41 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fifth lens group G5 includes the plano-convex lens L51 having a convex surface facing the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1 moved toward the object side, the second lens group G2 moved toward the image surface side and then moved toward the object side, the third lens group G3 and the fourth lens group G4 moved toward the object side, and the fifth lens group G5 fixed in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases, and the distance between the fourth lens group G4 and the fifth lens group G5 increases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the object side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the negative meniscus lens L41 forming the fourth lens group G4 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 38, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.195 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.229 mm when the correction angle is 0.472°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.243 mm when the correction angle is 0.369°.
In Table 38 below, specification values in Example are listed. Surface numbers 1 to 25 in Table 38 respectively correspond to the optical surfaces m1 to m25 in FIG. 44.







TABLE 38







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
39.2736
1.40
17.98
1.94594


2
32.2014
5.24
54.61
1.72916


3
170.2584
 D3(variable)




4
126.0761
1.00
40.66
1.88300


5
10.8699
5.87(variable)




*6
−27.7763
1.10
40.10
1.85135


*7
−572.4387
0.25




8
64.8806
1.84
17.98
1.94594


9
−69.0576
 D9(variable)




*10
15.3606
1.90
40.10
1.85135


11
88.6041
1.80




12
∞
1.50
(aperture stop)



13
12.9024
2.75
82.57
1.49782


14
−32.4325
1.00
28.69
1.79504


15
11.9088
2.39




*16
47.0932
1.37
61.25
1.58913


17
−41.7476
D17(variable)




18
17.4125
2.43
82.57
1.49782


19
125522.6100
D19(variable)




*20
191.9512
1.00
40.10
1.85135


*21
16.2810
1.54




22
24.7940
1.68
23.47
1.79816


23
78.0304
D23(variable)




24
53.6440
2.03
70.32
1.48749


25
∞
D25(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





6th surface
0.00
−6.15138E−05
−1.22714E−07
2.85742E−09
−1.48646E−11


7th surface
0.00
−8.15979E−05
 7.12457E−08
4.52409E−10
 0.00000E+00


10th surface
0.00
−1.10452E−05
 4.45196E−08
4.92428E−10
 0.00000E+00


16th surface
0.00
−6.45246E−05
−2.47179E−07
−4.16089E−09 
−1.98995E−10


20th surface
0.00
 2.84055E−05
−1.57415E−06
4.74078E−08
−4.66542E−10


21st surface
0.00
 2.79016E−05
−1.57812E−06
3.70868E−08
−3.33684E−10










[Various data]


Zoom ratio 3.24













Wide angle

Telephoto




end
Intermediate
end






f
16.5~
32.6~
53.4



FNO
2.9~
3.7~
4.1



2ω
81.7~
47.0~
29.0



Y
12.4~
14.3~
14.3



TL(air)
76.5~
85.0~
98.2



BF(air)
15.0~
15.0~
15.0











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
16.5
32.6
53.4
16.5
32.6
53.4


D3
1.06
11.63
22.04





D9
15.36
4.78
0.80





D17
2.94
2.94
2.94
2.18
0.75
0.00


D19
1.00
4.71
5.22
1.76
6.91
8.16


D23
3.03
7.84
14.02





D25
15.00
15.00
15.01










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
74.13



Second lens group
4
−14.07



Third lens group
10
18.25



Fourth lens group
20
−41.09



Fifth lens group
24
110.04










[Conditional expression corresponding value]





Conditional expression(JK1) |fF|/fM = 1.917


Conditional expression(JK2) (−fXn)/fM = 0.771


Conditional expression(JK3) dAB/|fF| = 0.084


Conditional expression(JK4) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JK5) νdp = 82.57


Conditional expression(JM1) dV/|fV| = 0.073


Conditional expression(JM2) |fF|/fM = 1.917


Conditional expression(JM3) dAB/|fF| = 0.084


Conditional expression(JM4) (−fXn)/fM = 0.771


Conditional expression(JM5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JM6) νdp = 82.57


Conditional expression(JN1) |fF|/fM = 1.917


Conditional expression(JN2) dV/|fV| = 0.073


Conditional expression(JN3) dAB/|fF| = 0.084


Conditional expression(JN4) (−fXn)/fM = 0.771


Conditional expression(JN5) ndp + 0.0075 × νdp − 2.175 = −0.058


Conditional expression(JN6) νdp = 82.57









It can be seen in Table 38 that the zoom optical system ZL38 according to this Example satisfies the conditional expressions (JK1) to (JK5), (JM1) to (JM6), and (JN1) to (JN6).
Example 39
Example 39 is described with reference to FIG. 45 and Table 39. A zoom optical system ZLII (ZL39) according to Example 39 includes, as illustrated in FIG. 45, the first lens group G1 having positive refractive power, the second lens group G2 having negative refractive power, the third lens group G3 having positive refractive power, the fourth lens group G4 having positive refractive power, the fifth lens group G5 having negative refractive power, and the sixth lens group G6 having negative refractive power that are arranged in order from the object side.
The first lens group G1 includes: the cemented lens including the plano-concave lens L11 having a concave surface facing the image side and the biconvex lens L12; and the positive meniscus lens L13 having a convex surface facing the object side that are arranged in order from the object side.
The second lens group G2 includes the negative meniscus lens L21 having a concave surface facing the image side, the biconcave lens L22, the biconvex lens L23, and the negative meniscus lens L24 having a concave surface facing the object side that are arranged in order from an object side. The biconcave lens L22 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The third lens group G3 includes the object side group GA and the image side group GB having negative refractive power that are arranged in order from the object side. The object side group GA includes the biconvex lens L31, the aperture stop S, and the cemented lens including the negative meniscus lens L32 having a convex surface facing the image side and the biconvex lens L33 that are arranged in order from the object side. The image side group GB includes the negative meniscus lens L34 having a concave surface facing the image side. The biconvex lens L31 is a glass-molded aspherical lens with lens surfaces, on the object side and on the image surface side, having an aspherical shape.
The fourth lens group G4 includes a cemented lens including the biconvex lens L41 and the negative meniscus lens L42 having a concave surface facing the object side that are arranged in order from the object side. The biconvex lens L41 is a glass-molded aspherical lens with a lens surface, on the object side, having an aspherical shape.
The fifth lens group G5 includes the negative meniscus lens L51 having a concave surface facing the image side.
The sixth lens group G6 includes: the biconvex lens L61; a cemented lens including the positive meniscus lens L62 having a convex surface facing the image side and a negative meniscus lens L63 having a concave surface facing the object side; and a negative meniscus lens L64 having a concave surface facing the object side that are arranged in order from the object side.
The zooming from the wide angle end state to the telephoto end state is achieved with: the first lens group G1, the second lens group G2, the third lens group G3, the fourth lens group G4, the fifth lens group G5, and the sixth lens group G6 moved toward the object side in such a manner that the distance between the first lens group G1 and the second lens group G2 increases, the distance between the second lens group G2 and the third lens group G3 decreases, the distance between the third lens group G3 and the fourth lens group G4 increases and then decreases, the distance between the fourth lens group G4 and the fifth lens group G5 increases, and the distance between the fifth lens group G5 and the sixth lens group G6 decreases.
Focusing from infinity to the short-distant object is achieved with the image side group GB (=focusing lens group GF) forming the third lens group G3 moved toward the image side.
When image blur occurs, image blur correction (vibration isolation) on the image surface I is performed with the fifth lens group G5 serving as the vibration-proof lens group VR moved with a displacement component in the direction orthogonal to the optical axis. In Example 39, in the wide angle end state, the shifted amount of the vibration-proof lens group VR is −0.377 mm when the correction angle is 0.664°. In the intermediate focal length state, the shifted amount of the vibration-proof lens group VR is −0.359 mm when the correction angle is 0.469°. In the telephoto end state, the shifted amount of the vibration-proof lens group VR is −0.390 mm when the correction angle is 0.363°.
In Table 39 below, specification values in Example are listed. Surface numbers 1 to 33 in Table 39 respectively correspond to the optical surfaces m1 to m33 in FIG. 45.







TABLE 39







[Lens specifications]











Surface number
R
D
νd
nd





Obj surface
∞





1
∞
2.00
22.74
1.80809


2
168.6059
5.45
67.90
1.59319


3
−204.1381
0.10




4
47.0069
4.19
54.61
1.72916


5
85.1045
 D5(variable)




6
57.0314
1.35
35.72
1.90265


7
17.0881
8.40




*8
−35.0755
1.00
51.16
1.75501


9
63.8129
0.10




10
40.8145
5.10
22.74
1.80809


11
−52.9940
2.58




12
−23.0315
1.20
58.12
1.62299


13
−51.0036
D13(variable)




*14
74.2220
4.11
54.04
1.72903


*15
−69.8827
1.00




16
∞
5.48
(aperture stop)



17
59.9122
1.00
33.72
1.64769


18
28.9118
6.78
82.57
1.49782


19
−25.7826
D19(variable)




20
1008.1852
1.00
56.24
1.65100


21
30.4711
D21(variable)




*22
27.9558
5.40
67.02
1.59201


23
−42.4982
1.00
35.72
1.90265


24
−64.8363
D24(variable)




25
223.4467
1.00
35.25
1.74950


26
31.2261
D26(variable)




27
33.7181
7.66
81.56
1.49710


28
−23.5370
0.14




29
−30.5959
7.89
22.74
1.80809


30
−18.2842
1.35
40.66
1.88300


31
−46.5493
3.09




32
−19.1643
1.30
54.61
1.72916


33
−95.9930
D33(variable)




Img surface
∞













[Aspherical data]












Surface number
κ
A4
A6
A8
A10





8th surface
0.00
2.89684E−06
−1.52154E−09 
9.65135E−12
1.80551E−13


14th surface
0.00
6.80639E−06
8.87567E−08
3.26125E−11
0.00000E+00


15th surface
0.00
2.37132E−05
9.36004E−08
2.05650E−10
−1.50000E−13 


22nd surface
0.00
1.59007E−07
1.94525E−09
−5.68547E−11 
0.00000E+00










[Various data]


Zoom ratio 3.34













Wide angle

Telephoto




end
Intermediate
end






f
24.7~
49.5~
82.5



FNO
2.9~
3.9~
4.1



2ω
82.4~
47.2~
28.8



Y
19.1~
21.5~
21.6



TL(air)
128.0~
142.7~
166.0



BF(air)
14.9~
31.1~
39.2











[Variable distance data]












Upon focusing on infinity
Upon focusing on short distant object















Wide angle

Telephoto
Wide angle

Telephoto



end
Intermediate
end
end
Intermediate
end





f
24.7
49.5
82.5
24.7
49.5
82.5


D5
1.10
13.39
32.72





D13
17.85
5.59
1.10





D19
1.61
1.61
1.61
2.52
4.25
7.87


D21
6.67
6.51
6.55
5.76
3.86
0.29


D24
1.50
3.27
3.61





D26
4.69
1.57
1.54





D33
14.89
31.13
39.20










[Lens group data]












Group
Group




starting surface
focal length






First lens group
1
111.42



Second lens group
6
−18.73



Third lens group
14
38.98



Fourth lens group
22
36.75



Fifth lens group
25
−48.54



Sixth lens group
27
−703.75










[Conditional expression corresponding value]





Conditional expression(JL1) |(rB + rA)/(rB − rA)| = 23.228


Conditional expression(JL2) |fF|/fM = 1.239


Conditional expression(JL3) dAB/|fF| = 0.136


Conditional expression(JL4) (−fXn)/fM = 0.480


Conditional expression(JL7) ndn + 0.0075 × νdn − 2.175 = −0.102


Conditional expression(JL8) νdn = 56.24


Conditional expression(JM1) dV/|fV| = 0.032


Conditional expression(JM2) |fF|/fM = 1.239


Conditional expression(JM3) dAB/|fF| = 0.136


Conditional expression(JM4) (−fXn)/fM = 0.480


Conditional expression(JM7) ndn + 0.0075 × νdn − 2.175 = −0.102


Conditional expression(JM8) νdn = 56.24


Conditional expression(JN1) |fF|/fM = 1.239


Conditional expression(JN2) dV/|fV| = 0.032


Conditional expression(JN3) dAB/|fF| = 0.136


Conditional expression(JN4) (−fXn)/fM = 0.480


Conditional expression(JN7) ndn + 0.0075 × νdn − 2.175 = −0.102


Conditional expression(JN8) νdn = 56.24









It can be seen in Table 39 that the zoom optical system ZL39 according to this Example satisfies the conditional expressions (JL1) to (JL4), (JL7), (JL8), (JM1) to (JM4), (JM7), (JM8), (JN1) to (JN4), (JN7), and (JN8).
Examples described above can achieve the zoom optical system featuring a small size, small variation of image magnification upon focusing, and an excellent optical performance.
Elements of the embodiments are described above to facilitate the understanding of the present invention. It is a matter of course that the present invention is not limited to these. The following configurations can be appropriately employed without compromising the optical performance of the zoom optical system according to the present application.
The numerical values of the configuration with the four groups, five groups, or six groups are described as an example of values of the zoom optical system ZLII according to the 11th to the 14th embodiments. However, this should not be construed in a limiting sense, and the present invention can be applied to a configuration with other number of groups (for example, seven groups or the like). More specifically, a configuration further provided with a lens or a lens group closest to an object or further provided with a lens or a lens group closest to the image may be employed. The first to the sixth lens groups, the front-side lens group, the intermediate lens group, and the rear-side lens group are each a portion including at least one lens separated from another lens with a distance varying upon zooming. The focusing lens group GF is a portion including at least one lens separated from another lens with a distance varying upon focusing. The vibration-proof lens group is a portion including at least one lens and is defined by a portion that moves upon image stabilization and a portion that does not move upon image stabilization.
In the zoom optical system ZLII according to the 11th to the 14th embodiments may have the following configuration. Specifically, upon focusing on a short-distant object from infinity, part of a lens group, one entire lens group, or a plurality of lens groups may be moved in the optical axis direction as the focusing lens group. The focusing lens group may be applied to auto focusing, and can be suitably driven by a motor (such as an ultrasonic motor for example) for auto focusing.
In the zoom optical system ZLII according to the 11th to the 14th embodiments, any of the lens group may be entirely or partially moved with a component in a direction orthogonal to the optical axis, or may be moved and rotated (swing) within an in-plane direction including the optical axis, to serve as the vibration-proof lens group for correcting image blur due to camera shake or the like. At least part of the fourth lens group G4 or at least part of the fifth lens group G5 is especially preferably used as the vibration-proof lens group.
In the zoom optical system ZLII according to the 11th to the 14th embodiments, the lens surface may be formed to have a spherical surface or a planer surface, or may be formed to have an aspherical shape. The lens surface having a spherical surface or a planer surface features easy lens processing and assembly adjustment, which leads to the processing and assembly adjustment less likely to involve an error compromising the optical performance, and thus is preferable. Furthermore, there is an advantage that a rendering performance is not largely compromised even when the image surface is displaced. The lens surface having an aspherical shape may be achieved with any one of an aspherical shape formed by grinding, a glass-molded aspherical shape obtained by molding a glass piece into an aspherical shape, and a composite type aspherical surface obtained by providing an aspherical shape resin piece on a glass surface. A lens surface may be a diffractive surface. The lens may be a gradient index lens (GRIN lens) or a plastic lens.
In the zoom optical system ZLII according to the 11th to the 14th embodiments, the aperture stop S is preferably disposed in the neighborhood of the third lens group G3. Alternatively, a lens frame may serve as the aperture stop so that the member serving as the aperture stop needs not to be provided.
In the zoom optical system ZLII according to the 11th to the 14th embodiments, the lens surfaces may be provided with an antireflection film featuring high transmittance over a wide range of wavelengths to achieve an excellent optical performance with reduced flare and ghosting and increased contract.
The zoom optical system ZLII according to the 11th to the 14th embodiment has a zooming rate of about 300 to 450%.
EXPLANATION OF NUMERALS AND CHARACTERS


    
    
        ZLI (ZL1 to ZL14) zoom optical system (1st to 10th embodiments)
        ZLII (ZL15 to ZL39) zoom optical system (11th to 14th embodiments)
        G1 first lens group
        G2 second lens group
        G3 third lens group
        GA object side group
        GB image side group
        G4 fourth lens group
        G5 fifth lens group
        G6 sixth lens group
        GX front-side lens group
        GM intermediate lens group
        GR rear-side lens group
        GF focusing lens group
        VR vibration-proof lens group
        S aperture stop
        I image surface
        1, 11 camera (optical device)

## Claims

1. A zoom optical system comprising, in order from an object side:
a first lens group having positive refractive power; a front-side lens group;
an intermediate lens group having positive refractive power; and
a rear-side lens group,
wherein
the front-side lens group is composed of one or more lens groups and has a negative lens group,
at least part of the intermediate lens group is a focusing lens group,
the rear-side lens group is composed of one or more lens groups,
upon zooming, a distance between the first lens group and the front-side lens group is changed, a distance between the front-side lens group and the intermediate lens group is changed, and a distance between the intermediate lens group and the rear-side lens group is changed, and
the following conditional expressions are satisfied:


−10.000<fF/fRF<10.000



0.010<|fF/fXR|<10.000



0.100<DGXR/fXR<1.500



2.250<TLW/ZD1<10.000


where
fF denotes a focal length of the focusing lens group,
fRF denotes a focal length of a lens group closest to the object side in the rear-side lens group,
fXR denotes a focal length of a lens group closet to an image surface in the front-side lens group,
DGXR denotes a thickness of the lens group closest to an image in the front-side lens group on an optical axis,
TLW denotes an entire lentght of the optical system in a wide angle end state, and
ZD1 denotes a movement amount of the first lens group upon zooming from the wide angle end state to a telephoto end state.

2. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


−10.000<fRF/fRF2<10.000

where
fRF2 denotes a focal length of a lens group second closest to the object side in the rear-side lens group.

3. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


32.000≤Wω

where
Wω: a half angle of view in the wide angle end state.

4. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


Tω≤20.000

where
Tω denotes a half angle of view in telephoto end state.

5. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


0.000<βFw<0.800

where
βFw denotes a lateral magnification of the focusing lens group in the wide angle end state.

6. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


0.010<fF/fW<8.000

where
fW denotes a focal length of the entire system in wide angle end state.

7. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


0.420<(−fXn)/fXR<2.000

where
fXn denotes a focal length of a lens group with a largest absolute value of refractive power in a negative lens group of the front-side lens group.

8. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


0.010<(−fXn)/fXR<1.000

where
fXn denotes a focal length of a lens group with a largest absolute value of refractive power in a negative lens group of the front-side lens group.

9. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


0.170<|fF/fRF|<10.000.

10. The zoom optical system according to claim 1, wherein the following conditional expression is satisfied:


0.010<fF/fXR<10.000.

11. An optical device comprising the zoom optical system according to claim 1.

12. A method for manufacturing a zoom optical system, comprising:
arranging, in a lens barrel and in order from an object side, a first lens group having positive refractive power, a front-side lens group, an intermediate lens group having positive refractive power, and a rear-side lens group,
the front-side lens group being composed of one or more lens groups and having a negative lens group,
at least part of the intermediate lens group being a focusing lens group,
the rear-side lens group being composed of one or more lens groups,
the arrangement being such that upon zooming, a distance between the first lens group and the front-side lens group is changed, a distance between the front-side lens group and the intermediate lens group is changed, and a distance between the intermediate lens group and the rear-side lens group is changed; and
satisfying the following conditional expressions:


−10.000<fF/fRF<10.000



0.010<|fF/fXR|<10.000



0.100<DGXR/fXR<1.500



2.250<TLW/ZD1<10.000


where
fF denotes a focal length of the focusing lens group,
fRF denotes a focal length of a lens group closest to the object side in the rear-side lens group,
fXR denotes a focal length of a lens group closet to an image surface in the front-side lens group,
DGXR denotes a thickness of the lens group closest to an image in the front-side lens group on an optical axis,
TLW denotes an entire lentght of the optical system in a wide angle end state, and
ZD1 denotes a movement amount of the first lens group upon zooming from the wide angle end state to a telephoto end state.