Abstract:
A zoom lens system includes a positive first lens group and a negative second lens group. The first lens group includes a cemented lens, a diffraction surface having a rotationally symmetric shape satisfying condition (1) formed on a cemented surface of the cemented lens, and condition (2) is satisfied: 
       130&lt;| fD/RD |&lt;10,000( fD &gt;0)  (1),
 
       and 
       0.15&lt; f 1/ fT &lt;0.35  (2).
 
     fD designates the focal length of the diffraction surface; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface, λ0 designates the d-line, RD designates the radius of curvature of the substrate surface having the diffraction surface and fT designates the focal lengths of the entire lens system at the long focal length extremity.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a zoom lens system for use in, e.g., a day-and-night surveillance lens system (day-and-night lens). 
       BACKGROUND ART 
       [0002]    In recent years there has been a demand for zoom lens systems to be more compact (miniaturized), and to have a higher zoom ratio, especially when the focal length is zoomed out to a long focal length for telescopic surveillance. Furthermore, a day-and-night surveillance lens system has been in demand for surveillance use in which the imaging-plane position does not shift from the visible region to the near infra-red region. In order to meet the latter demand, the wavelength range for correcting axial chromatic aberration must be broadened to the near infra-red region, however, the longer the focal length is zoomed out to, the greater the amount of chromatic aberration, which is difficult to favorably correct. 
         [0003]    Using an anomalous dispersion glass element is known to be effective for correcting chromatic aberration, especially chromatic aberration in the secondary spectrum; however, since the refractive index of anomalous dispersion glass is low, in order to correct chromatic aberration without deterioration in the suppression of the various aberrations, a large number of lens elements are required, thereby increasing the overall length of the lens system. 
         [0004]    On the other hand, correcting chromatic aberration using a diffraction optical element is known. For example, Patent Literature Nos. 1 through 7 disclose providing a diffraction optical element in a positive powered first lens group of a zoom lens system configured of a positive lens group, a negative lens group, a negative lens group and a positive lens group (four lens groups), a zoom lens system configured of a positive lens group, a negative lens group, a positive lens group and a positive lens group (four lens groups), or a zoom lens system configured of a positive lens group, a negative lens group, a positive lens group, a negative lens group and a positive lens group (five lens groups). 
         [0005]    However, all of the zoom lens systems in Patent Literature Nos. 1 through 7 have technical problems, such as having an excessive number of lens elements, thereby increasing the overall length of the lens system; the focal length at the long focal-length side being too small, so that the zoom ratio is insufficient for a telephoto lens system; and it being difficult to correct chromatic aberration over the entire zooming range from the visible region to the near infra-red region; so that the optical quality of these zoom lens systems is insufficient for use in a day-and-night surveillance lens system. Furthermore, if a diffraction optical element is provided, unless the diffraction surface is provided at an appropriate position, the optical power is controlled and an appropriate glass material is chosen, it becomes difficult to favorably correct chromatic aberration from the visible region through to a near infra-red region without deterioration in the suppression of various aberrations. 
       CITATION LIST 
     Patent Literature 
       [0006]    Patent Literature 1: Japanese Patent No. 4,928,297 
         [0007]    Patent Literature 2: Japanese Unexamined Patent Publication No. 2003-287678 
         [0008]    Patent Literature 3: Japanese Unexamined Patent Publication No. 2000-221402 
         [0009]    Patent Literature 4: Japanese Unexamined Patent Publication No. 2004-126396 
         [0010]    Patent Literature 5: Japanese Unexamined Patent Publication No. 2000-121821 
         [0011]    Patent Literature 6: Japanese Patent No. 4,182,088 
         [0012]    Patent Literature 7: Japanese Patent No. 4,764,051 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0013]    The present invention has been devised in view of the above-described problems and an object of the present invention is to achieve a zoom lens system, which is suitable for use in a day-and-night surveillance lens system, having a short overall length, the focal length at the long focal-length side is increased to attain a high zoom ratio, and which can achieve a superior optical quality by favorably correcting chromatic aberration over the entire zooming range from the visible region to the near infra-red region. 
       Solution to Problem 
       [0014]    In an embodiment of a zoom lens system according to the present invention, a zoom lens system is provided, including at least a positive first lens group and a negative second lens group, in that order from the object side, wherein a distance between the first lens group and the second lens group increases while zooming from the short focal length extremity to the long focal length extremity. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (1) is formed on a cemented surface of at least one of the cemented lens, and the following condition (2) is satisfied: 
         [0000]      130&lt;| fD/RD|&lt; 10,000( fD&gt; 0)  (1),
 
         [0000]      and 
         [0000]      0.15&lt; f 1/ fT&lt; 0.35  (2),
 
         [0000]    wherein fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, RD designates the radius of curvature of the substrate surface having the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, f1 designates the focal length of the first lens group, and fT designates the focal length of the entire lens system at the long focal length extremity. 
         [0015]    In the zoom lens system of the present invention, it is desirable for the first lens group to include at least one negative lens element and for the following conditions (3) and (4) to be satisfied: 
         [0000]      ν n 1&gt;33  (3),
 
         [0000]      and 
         [0000]      θ gFn 1&lt;0.59  (4),
 
         [0000]    wherein νn1 designates the Abbe number at the d-line of the at least one negative lens element of negative lens elements that are provided in the first lens group, and θgFn1 designates the partial dispersion ratio of the at least one negative lens element of negative lens elements that are provided in the first lens group. 
         [0016]    In another embodiment of the zoom lens system of the present invention, a zoom lens system is provided, including at least a positive first lens group and a negative second lens group, in that order from the object side, wherein, while zooming from the short focal length extremity to the long focal length extremity, the first lens group remains stationary relative to the imaging plane, and a distance between the first lens group and the second lens group increases by the second lens group moving toward the image side. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (1) is formed on a cemented surface of at least one of the cemented lens, the first lens group includes at least one negative lens element, and the following conditions (3) and (4) are satisfied: 
         [0000]      130&lt;| fD/RD|&lt; 10,000( fD&gt; 0)  (1),
 
         [0000]      ν n 1&gt;33  (3),
 
         [0000]      and 
         [0000]      θ gFn 1&lt;0.59  (4),
 
         [0000]    wherein fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, RD designates the radius of curvature of the substrate surface having the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, νn1 designates the Abbe number at the d-line of the at least one negative lens element of negative lens elements that are provided in the first lens group, and θgFn1 designates the partial dispersion ratio of the at least one negative lens element of negative lens elements that are provided in the first lens group. 
         [0017]    In the zoom lens system of the present invention, it is desirable for the following condition (2) to be satisfied: 
         [0000]      0.15&lt; f 1/ fT&lt; 0.35  (2),
 
         [0000]    wherein f1 designates the focal length of the first lens group, and fT designates the focal length of the entire lens system at the long focal length extremity. 
         [0018]    In the zoom lens system of the present invention, it is desirable for the first lens group to include at least one positive lens element, and for the following condition (5) to be satisfied: 
         [0000]      ν p 1&gt;71  (5),
 
         [0000]    wherein νp1 designates the Abbe number at the d-line of the at least one positive lens element provided within the first lens group. 
         [0019]    In the zoom lens system of the present invention, it is desirable for the following condition (6) to be satisfied: 
         [0000]      2.9&lt; f 1/1 gD&lt; 6.5  (6),
 
         [0000]    wherein f1 designates the focal length of the first lens group, and 1gD designates the distance from the surface closest to the object side on the first lens group to the surface closest to the image side on the first lens group (the thickness of the first lens group). 
         [0020]    It is desirable for each lens element of the cemented lens that is provided within the first lens group to include a resin material on an opposing substrate glass, wherein a diffraction surface is formed on a boundary surface between the resin materials. 
         [0021]    In the zoom lens system of the present invention, it is desirable for the second lens group to include at least one positive lens element, and for the following condition (7) to be satisfied: 
         [0000]      ν p 2&lt;23  (7),
 
         [0000]    wherein νp2 designates the Abbe number at the d-line of the at least one positive lens element provided within the second lens group. 
         [0022]    In the zoom lens system of the present invention, it is desirable for the following condition (8) to be satisfied: 
         [0000]      −0.8&lt; f 2/( fW×fT ) 1/2 &lt;−0.2  (8),
 
         [0000]    wherein f2 designates the focal length of the second lens group, fW designates the focal length of the entire lens system at the short focal length extremity, and fT designates the focal length of the entire lens system at the long focal length extremity. 
         [0023]    It is desirable for the zoom lens system of the present invention to further include a positive or negative stationary lens group, at a position closest to the image side, which is stationary relative to the imaging plane during zooming from the short focal length extremity to the long focal length extremity, wherein the following condition (9) is satisfied: 
         [0000]      | mL|&lt; 1.2  (9),
 
         [0000]    wherein mL designates the lateral magnification of the stationary lens group that is positioned closest to the image side. 
         [0024]    It is desirable for the zoom lens system of the present invention to further include a positive or negative stationary lens group, at a position closest to the image side, which is stationary relative to the imaging plane during zooming from the short focal length extremity to the long focal length extremity, wherein the stationary lens group includes at least one positive lens element, and wherein the following condition (10) is satisfied: 
         [0000]      ν pL&gt; 71  (10),
 
         [0000]    wherein νpL designates the Abbe number at the d-line of the at least one positive lens element provided within the stationary lens group that is positioned closest to the image side. 
         [0025]    It is desirable for the zoom lens system of the present invention to further include a negative third lens group, behind the second lens group, which moves during zooming from the short focal length extremity to the long focal length extremity, wherein the following condition (11) is satisfied: 
         [0000]      0.9&lt; f 2/ f 3&lt;2.5  (11),
 
         [0000]    wherein f2 designates the focal length of the second lens group, and f3 designates the focal length of the third lens group 
         [0026]    In the zoom lens system of the present invention, a negative third lens group and a positive fourth lens group can be provided behind the second lens group. 
         [0027]    In such a case, the second lens group can include a negative lens element, and a cemented lens provided with a positive lens element and a negative lens element, in that order from the object side. 
         [0028]    The zoom lens system of the present invention can be further provided, behind the second lens group, with a positive third lens group and a negative fourth lens group. 
         [0029]    The zoom lens system of the present invention can be further provided, behind the second lens group, with a positive third lens group, a negative fourth lens group, and a positive fifth lens group. 
         [0030]    In another embodiment of the present invention, a zoom lens system is provided, including at least a positive first lens group and a negative second lens group, in that order from the object side, wherein, while zooming from the short focal length extremity to the long focal length extremity, the first lens group remains stationary relative to the imaging plane, and a distance between the first lens group and the second lens group increases by the second lens group moving toward the image side. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (1) is formed on a cemented surface of at least one of the cemented lens, the first lens group includes at least one positive lens element, and the following condition (5) is satisfied: 
         [0000]      130&lt;| fD/RD|&lt; 10,000( fD&gt; 0)  (1),
 
         [0000]      and 
         [0000]      ν p 1&gt;71  (5),
 
         [0000]    wherein fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, RD designates the radius of curvature of the substrate surface having the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, and νp1 designates the Abbe number at the d-line of the at least one positive lens element provided within the first lens group. 
         [0031]    In another embodiment of the present invention, a zoom lens system is provided, including at least a positive first lens group and a negative second lens group, in that order from the object side, wherein, while zooming from the short focal length extremity to the long focal length extremity, the first lens group remains stationary relative to the imaging plane and a distance between the first lens group and the second lens group increases by the second lens group moving toward the image side. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (1) is formed on a cemented surface of at least one of the cemented lens, the second lens group includes at least one positive lens element, and the following condition (7) is satisfied: 
         [0000]      130&lt;| fD/RD|&lt; 10,000( fD&gt; 0)  (1),
 
         [0000]      and 
         [0000]      ν p 2&lt;23  (7),
 
         [0000]    wherein fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, RD designates the radius of curvature of the substrate surface having the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, and νp2 designates the Abbe number at the d-line of the at least one positive lens element provided within the second lens group. 
         [0032]    In another embodiment of the present invention, a zoom lens system is provided, including at least a positive first lens group, a negative second lens group and a negative third lens group, in that order from the object side, wherein, while zooming from the short focal length extremity to the long focal length extremity, the first lens group remains stationary relative to the imaging plane, and a distance between the first lens group and the second lens group increases by the second lens group moving toward the image side. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (1) is formed on a cemented surface of at least one of the cemented lens, and the following condition (11) is satisfied: 
         [0000]      130&lt;| fD/RD|&lt; 10,000( fD&gt; 0)  (1),
 
         [0000]      and 
         [0000]      0.9&lt; f 2/ f 3&lt;2.5  (11),
 
         [0000]    wherein fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, RD designates the radius of curvature of the substrate surface having the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, f2 designates the focal length of the second lens group, and f3 designates the focal length of the third lens group. 
         [0033]    In another embodiment of the present invention, a zoom lens system is provided, including at least a positive first lens group and a negative second lens group, in that order from the object side, wherein, while zooming from the short focal length extremity to the long focal length extremity, the first lens group remains stationary relative to the imaging plane, and a distance between the first lens group and the second lens group increases by the second lens group moving toward the image side. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (1) is formed on a cemented surface of at least one of the cemented lens, and an angle between each principal ray, which is incident on the diffraction surface formed on the cemented surface of the cemented lens of the first lens group, and the optical axis is 13° or less: 
         [0000]      130&lt;| fD/RD|&lt; 10,000( fD&gt; 0)  (1),
 
         [0000]    wherein fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, and RD designates the radius of curvature of the substrate surface having the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group. 
         [0034]    In another embodiment of the present invention, a zoom lens system is provided, including at least a positive first lens group and a negative second lens group, in that order from the object side, wherein a distance between the first lens group and the second lens group increases while zooming from the short focal length extremity to the long focal length extremity. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (12) is formed on a cemented surface of at least one of the cemented lens, and the following condition (2) is satisfied: 
         [0000]      0.15&lt; f 1/ fT&lt; 0.35  (2),
 
         [0000]      and 
         [0000]      130&lt; fD/f 1( fD&gt; 0)  (12),
 
         [0000]    wherein f1 designates the focal length of the first lens group, fT designates the focal length of the entire lens system at the long focal length extremity, fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, and λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group. 
         [0035]    In another embodiment of the present invention, a zoom lens system is provided, including at least a positive first lens group, a negative second lens group and a negative third lens group, in that order from the object side, wherein, while zooming from the short focal length extremity to the long focal length extremity, the first lens group remains stationary relative to the imaging plane, and a distance between the first lens group and the second lens group increases by the second lens group moving toward the image side. The first lens group includes at least one cemented lens, a diffraction surface having a rotationally symmetric shape with respect to the optical axis and satisfying the following condition (12) is formed on a cemented surface of at least one of the cemented lens, and the following condition (11) is satisfied: 
         [0000]      0.9&lt; f 2/ f 3&lt;2.5  (11),
 
         [0000]      and 
         [0000]      130&lt; fD/f 1( fD&gt; 0)  (12),
 
         [0000]    wherein f2 designates the focal length of the second lens group, f3 designates the focal length of the third lens group, fD designates the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group; fD=−1/(2×P2×λ0); P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group, and λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed on the cemented surface of the cemented lens, provided within the first lens group. 
         [0036]    It is desirable for the zoom lens system of the present invention to satisfy the following condition (1′) within the scope of condition (1): 
         [0000]      200&lt;| fD/RD|&lt; 10,000( fD&gt; 0)  (1′).
 
         [0037]    It is desirable for the zoom lens system of the present invention to satisfy the following condition (12′) within the scope of condition (12): 
         [0000]      130&lt; fD/f 1&lt;10,000( fD&gt; 0)  (12′).
 
         [0038]    It is desirable for the zoom lens system of the present invention to satisfy the following condition (2′): 
         [0000]      0.14&lt; f 1/ fT&lt; 0.31  (2′).
 
         [0039]    It is desirable for the zoom lens system of the present invention to satisfy the following condition (12″) within the scope of condition (12): 
         [0000]      190&lt; fD/f 1&lt;10,000( fD&gt; 0)  (12″).
 
         [0040]    It is desirable for the zoom lens system of the present invention to include at least one positive lens element in the first lens group, and to satisfy condition (5) while simultaneously satisfying the following condition (13): 
         [0000]      θ gFp 1−(−5.0×10 −4   ×νp 1+0.5700)&gt;0  (13),
 
         [0000]    wherein θgFp1 designates the partial dispersion ratio of at least one positive lens element of the positive lens elements that are provided in the first lens group, and νp1 designates the Abbe number at the d-line of the at least one positive lens element of the positive lens elements that are provided in the first lens group. 
         [0041]    It is desirable for the zoom lens system of the present invention to include at least one positive lens element in the second lens group, and to satisfy condition (7) while simultaneously satisfying the following condition (14): 
         [0000]      θ gFp 2−(−1.0×10 −4   ×νp 2+0.6300)&gt;0  (14),
 
         [0000]    wherein θgFp2 designates the partial dispersion ratio of at least one positive lens element of the positive lens elements that are provided in the second lens group, and νp2 designates the Abbe number at the d-line of the at least one positive lens element of the positive lens elements that are provided in the second lens group. 
         [0042]    It is desirable for the zoom lens system of the present invention to satisfy the following condition (15): 
         [0000]      30&lt; fD/fT ( fD&gt; 0)  (15),
 
         [0000]    wherein 
         [0043]    fD designates the focal length of the diffraction surface that is formed on the cemented surface of a cemented lens which is provided within the first lens group, fD=−1/(2×P2×λ0), P2 designates a secondary coefficient of an optical path difference function for calculating an optical path length addition amount of the diffraction surface that is formed on the cemented surface of the cemented lens which is provided within the first lens group, λ0 designates a wavelength for calculating the focal length of the diffraction surface that is formed at the cemented surface of a cemented lens which is provided within the first lens group, and fT designates the focal length of the entire lens system at the long focal length extremity. 
         [0044]    It is desirable for the zoom lens system of the present invention to satisfy the following condition (15′) within the scope of condition (15): 
         [0000]      30&lt; fD/f 1&lt;10,000( fD&gt; 0)  (15′).
 
         [0045]    In the zoom lens system of the present invention, it is desirable for the second lens group to include a negative lens element, and a cemented lens configured of a positive lens element and a negative lens element, in that order from the object side, wherein the following condition (16) is satisfied: 
         [0000]      −5.0&lt;( L 21 f+L 21 r )/( L 21 f−L 21 r )&lt;0.9  (16),
 
         [0000]    wherein 
         [0046]    L21f designates the radius of curvature of a surface on the object side of a negative lens element that is provided closest to the object side within the second lens group, and 
         [0047]    L21r designates the radius of curvature of a surface on the image side of a negative lens element that is provided closest to the image side within the second lens group. 
       Advantageous Effects of Invention 
       [0048]    According to the present invention, a zoom lens system can be achieved, which is suitable for use in a day-and-night surveillance lens system, having a short overall length, the focal length at the long focal-length side being increased to attain a high zoom ratio, and which can achieve a superior optical quality by favorably correcting chromatic aberration over the entire zooming range from the visible region to the near infra-red region. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0049]      FIG. 1  shows a lens arrangement of a first numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0050]      FIG. 2  shows various aberrations that occurred in the zoom lens system shown in  FIG. 1  when focused on an object at infinity at the short focal length extremity; 
           [0051]      FIG. 3  shows various aberrations that occurred in the zoom lens system shown in  FIG. 1  when focused on an object at infinity at an intermediate focal length; 
           [0052]      FIG. 4  shows various aberrations that occurred in the zoom lens system shown in  FIG. 1  when focused on an object at infinity at the long focal length extremity; 
           [0053]      FIG. 5  shows a lens arrangement of a second numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0054]      FIG. 6  shows various aberrations that occurred in the zoom lens system shown in  FIG. 5  when focused on an object at infinity at the short focal length extremity; 
           [0055]      FIG. 7  shows various aberrations that occurred in the zoom lens system shown in  FIG. 5  when focused on an object at infinity at an intermediate focal length; 
           [0056]      FIG. 8  shows various aberrations that occurred in the zoom lens system shown in  FIG. 5  when focused on an object at infinity at the long focal length extremity; 
           [0057]      FIG. 9  shows a lens arrangement of a third numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0058]      FIG. 10  shows various aberrations that occurred in the zoom lens system shown in  FIG. 9  when focused on an object at infinity at the short focal length extremity; 
           [0059]      FIG. 11  shows various aberrations that occurred in the zoom lens system shown in  FIG. 9  when focused on an object at infinity at an intermediate focal length; 
           [0060]      FIG. 12  shows various aberrations that occurred in the zoom lens system shown in  FIG. 9  when focused on an object at infinity at the long focal length extremity; 
           [0061]      FIG. 13  shows a lens arrangement of a fourth numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0062]      FIG. 14  shows various aberrations that occurred in the zoom lens system shown in  FIG. 13  when focused on an object at infinity at the short focal length extremity; 
           [0063]      FIG. 15  shows various aberrations that occurred in the zoom lens system shown in  FIG. 13  when focused on an object at infinity at an intermediate focal length; 
           [0064]      FIG. 16  shows various aberrations that occurred in the zoom lens system shown in  FIG. 13  when focused on an object at infinity at the long focal length extremity; 
           [0065]      FIG. 17  shows a lens arrangement of a fifth numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0066]      FIG. 18  shows various aberrations that occurred in the zoom lens system shown in  FIG. 17  when focused on an object at infinity at the short focal length extremity; 
           [0067]      FIG. 19  shows various aberrations that occurred in the zoom lens system shown in  FIG. 17  when focused on an object at infinity at an intermediate focal length; 
           [0068]      FIG. 20  shows various aberrations that occurred in the zoom lens system shown in  FIG. 17  when focused on an object at infinity at the long focal length extremity; 
           [0069]      FIG. 21  shows a lens arrangement of a sixth numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0070]      FIG. 22  shows various aberrations that occurred in the zoom lens system shown in  FIG. 21  when focused on an object at infinity at the short focal length extremity; 
           [0071]      FIG. 23  shows various aberrations that occurred in the zoom lens system shown in  FIG. 21  when focused on an object at infinity at an intermediate focal length; 
           [0072]      FIG. 24  shows various aberrations that occurred in the zoom lens system shown in  FIG. 21  when focused on an object at infinity at the long focal length extremity; 
           [0073]      FIG. 25  shows a lens arrangement of a seventh numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0074]      FIG. 26  shows various aberrations that occurred in the zoom lens system shown in  FIG. 25  when focused on an object at infinity at the short focal length extremity; 
           [0075]      FIG. 27  shows various aberrations that occurred in the zoom lens system shown in  FIG. 25  when focused on an object at infinity at an intermediate focal length; 
           [0076]      FIG. 28  shows various aberrations that occurred in the zoom lens system shown in  FIG. 25  when focused on an object at infinity at the long focal length extremity; 
           [0077]      FIG. 29  shows a lens arrangement of an eighth numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0078]      FIG. 30  shows various aberrations that occurred in the zoom lens system shown in  FIG. 29  when focused on an object at infinity at the short focal length extremity; 
           [0079]      FIG. 31  shows various aberrations that occurred in the zoom lens system shown in  FIG. 29  when focused on an object at infinity at an intermediate focal length; 
           [0080]      FIG. 32  shows various aberrations that occurred in the zoom lens system shown in  FIG. 29  when focused on an object at infinity at the long focal length extremity; 
           [0081]      FIG. 33  shows a lens arrangement of a ninth numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0082]      FIG. 34  shows various aberrations that occurred in the zoom lens system shown in  FIG. 33  when focused on an object at infinity at the short focal length extremity; 
           [0083]      FIG. 35  shows various aberrations that occurred in the zoom lens system shown in  FIG. 33  when focused on an object at infinity at an intermediate focal length; 
           [0084]      FIG. 36  shows various aberrations that occurred in the zoom lens system shown in  FIG. 33  when focused on an object at infinity at the long focal length extremity; 
           [0085]      FIG. 37  shows a lens arrangement of a tenth numerical embodiment of a zoom lens system, according to the present invention, when focused on an object at infinity at the short focal length extremity; 
           [0086]      FIG. 38  shows various aberrations that occurred in the zoom lens system shown in  FIG. 37  when focused on an object at infinity at the short focal length extremity; 
           [0087]      FIG. 39  shows various aberrations that occurred in the zoom lens system shown in  FIG. 37  when focused on an object at infinity at an intermediate focal length; 
           [0088]      FIG. 40  shows various aberrations that occurred in the zoom lens system shown in  FIG. 37  when focused on an object at infinity at the long focal length extremity; 
           [0089]      FIG. 41  shows a lens arrangement of a Reference Example in which an extender has been inserted into the zoom lens system of  FIG. 37 ; 
           [0090]      FIG. 42  shows various aberrations that occurred in the zoom lens system shown in  FIG. 41  when focused on an object at infinity at the short focal length extremity; 
           [0091]      FIG. 43  shows various aberrations that occurred in the zoom lens system shown in  FIG. 41  when focused on an object at infinity at an intermediate focal length; 
           [0092]      FIG. 44  shows various aberrations that occurred in the zoom lens system shown in  FIG. 41  when focused on an object at infinity at the long focal length extremity; 
           [0093]      FIG. 45  shows a first zoom path of the zoom lens system according to the present invention; 
           [0094]      FIG. 46  shows a second zoom path of the zoom lens system according to the present invention; 
           [0095]      FIG. 47  shows a third zoom path of the zoom lens system according to the present invention; 
           [0096]      FIG. 48  shows a fourth zoom path of the zoom lens system according to the present invention; 
           [0097]      FIG. 49  shows a schematic view of the structure of the diffraction surface formed on the cemented surface of the cemented lens that is provided within the first lens group; 
           [0098]      FIG. 50  is a diagram showing the diffraction efficiency of the diffraction surface, formed on the cemented surface of the cemented lens that is provided within the first lens group, in the case where the diffraction surface incident angle is 0 degrees; and 
           [0099]      FIG. 51  is a diagram showing the diffraction efficiency of the diffraction surface, formed on the cemented surface of the cemented lens that is provided within the first lens group, in the case where the diffraction surface incident angle is 13 degrees. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0100]    The zoom lens system according to the present invention will be hereinafter discussed with reference to the drawings. 
         [0101]    In the present specification, “entire lens system” refers to the optical system until the object-emanated image is formed as a first real image (primary image). 
         [0102]    Furthermore, the Abbe number νd and the partial dispersion ratio θgF are as follows: 
         [0000]      ν d =( nd− 1)/( nF−nC ),
 
         [0000]      and 
         [0000]      θ gF =( ng−nF )/( nF−nC ),
 
         [0000]    wherein ng, nF, nd and nC respectively designate the refractive indexes of the material at the wavelength 435.84 nm (g-line), the wavelength 486.13 nm (F-line), the wavelength 587.56 nm (d-line) and the wavelength 656.27 nm (C-line). 
         [0103]    In the first through fifth, ninth and tenth numerical embodiments, the zoom lens system is configured of a positive first lens group G 1 , a negative second lens group G 2 , a negative third lens group G 3  and a positive fourth lens group G 4  (four lens groups constituting a positive-negative-negative-positive lens group configuration of a zoom lens system), in that order from the object side, as shown in the zoom path of  FIG. 45 . An aperture diaphragm S is positioned between the third lens group G 3  and the fourth lens group G 4  (immediately in front of the fourth lens group G 4 ). ‘I’ designates the imaging surface. 
         [0104]    In the zoom lens system of the first through fifth, ninth and tenth numerical embodiments, during zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the distance between the first lens group G 1  and the second lens group G 2  increases, the distance between the second lens group G 2  and the third lens group G 3  decreases, and the distance between the third lens group G 3  and the fourth lens group G 4  decreases. 
         [0105]    More specifically, during zooming from the short focal length extremity to the long focal length extremity, the first lens group G 1  and the fourth lens group G 4  remain stationary relative to the imaging surface I, the second lens group G 2  moves toward the image side while plotting a convex path that faces the image side, and the third lens group G 3  moves toward the image side while plotting a convex path that faces the object side. Focusing is carried out by moving the first lens group G 1  toward the object side. 
         [0106]    As shown in  FIG. 1 , in the first numerical embodiment, the first lens group G 1  is configured of a negative lens element  101 , a positive lens element  102  and a positive lens element  103 , in that order from the object side. The surface on the image side of the negative lens element  101  and the surface on the object side of the positive lens element  102  are cemented to each other, and a diffraction surface (diffraction lens surface) DS which is formed on the cemented surface has a rotationally symmetric shape with respect to the optical axis. 
         [0107]    As shown in  FIG. 5 , in the second numerical embodiment, the first lens group G 1  is configured of a negative lens element  111 , a positive lens element  112 , a negative lens element  113 , a positive lens element  114  and a positive lens element  115 , in that order from the object side. The surface on the image side of the negative lens element  111  and the surface on the object side of the positive lens element  112  are cemented to each other. The surface on the image side of the negative lens element  113  and the surface on the object side of the positive lens element  114  are cemented to each other, and a diffraction surface DS which has a rotationally symmetric shape with respect to the optical axis is formed on the cemented surface thereof. 
         [0108]    As shown in  FIGS. 9 ,  13 ,  33  and  37 , in the third, fourth, ninth and tenth numerical embodiments, the first lens group G 1  is configured of a negative lens element  121 , a positive lens element  122 , a positive lens element  123 , and a positive lens element  124 , in that order from the object side. The surface on the image side of the negative lens element  121  and the surface on the object side of the positive lens element  122  are cemented to each other, and a diffraction surface DS which has a rotationally symmetric shape with respect to the optical axis is formed on the cemented surface thereof. 
         [0109]    As shown in  FIG. 17 , in the fifth numerical embodiment, the first lens group G 1  is configured of a positive lens element  131 , a positive lens element  132 , a positive lens element  133 , a positive lens element  134  and a negative lens element  135 , in that order from the object side. The surface on the image side of the positive lens element  131  and the surface on the object side of the positive lens element  132  are cemented to each other, and a diffraction surface DS which has a rotationally symmetric shape with respect to the optical axis is formed on the cemented surface thereof. 
         [0110]    As shown in  FIGS. 1 ,  5 ,  9 ,  13 ,  17 ,  33  and  37 , in the first through fifth, ninth and tenth numerical embodiments, the second lens group G 2  is configured of a negative lens element  201 , a positive lens element  202  and a negative lens element  203 , in that order from the object side. The surface on the image side of the positive lens element  202  and the surface on the object side of the negative lens element  203  are cemented to each other. By configuring the second lens group G 2  in such a manner, the number of lens elements of the second lens group G 2  can be reduced while facilitating correction of coma throughout the entire zooming range. 
         [0111]    As shown in  FIGS. 1 ,  5 ,  9 ,  13 ,  17 ,  33  and  37 , in the first through fifth, ninth and tenth numerical embodiments, the third lens group G 3  is configured of a negative lens element  301  and a positive lens element  302 , in that order from the object side. The surface on the image side of the negative lens element  301  and the surface on the object side of the positive lens element  302  are cemented to each other. 
         [0112]    As shown in  FIG. 1 , in the first numerical embodiment, the fourth lens group G 4  is configured of a positive lens element  401 , a positive lens element  402 , a negative lens element  403 , a positive lens element  404  and a negative lens element  405 , in that order from the object side. The surface on the image side of the positive lens element  402  and the surface on the object side of the negative lens element  403  are cemented to each other. 
         [0113]    As shown in  FIGS. 5 ,  9  and  37 , in the second, third and tenth numerical embodiments, the fourth lens group G 4  is configured of a positive lens element  411 , a positive lens element  412 , a positive lens element  413 , a negative lens element  414 , a positive lens element  415  and a negative lens element  416 , in that order from the object side. The surface on the image side of the positive lens element  413  and the surface on the object side of the negative lens element  414  are cemented to each other. 
         [0114]    As shown in  FIGS. 13 and 33 , in the fourth and ninth numerical embodiments, the fourth lens group G 4  is configured of a positive lens element  421 , a positive lens element  422 , a negative lens element  423 , a positive lens element  424 , a negative lens element  425 , a negative lens element  426  and a positive lens element  427 , in that order from the object side. The surface on the image side of the positive lens element  422  and the surface on the object side of the negative lens element  423  are cemented to each other. The surface on the image side of the negative lens element  426  and the surface on the object side of the positive lens element  427  are cemented to each other. 
         [0115]    As shown in  FIG. 17 , in the fifth numerical embodiment, the fourth lens group G 4  is configured of a positive lens element  431 , a positive lens element  432 , a positive lens element  433 , a negative lens element  434 , a positive lens element  435 , a negative lens element  436  and a positive lens element  437 , in that order from the object side. The surface on the image side of the positive lens element  433  and the surface on the object side of the negative lens element  434  are cemented to each other. 
         [0116]    In the sixth numerical embodiment, the zoom lens system is configured of a positive first lens group G 1 ′, a negative second lens group G 2 ′, a positive third lens group G 3 ′ and a negative fourth lens group G 4 ′ (four lens groups constituting a positive-negative-positive-negative lens group configuration of a zoom lens system), in that order from the object side, as shown in the zoom path of  FIG. 46 . An aperture diaphragm S is positioned between the third lens group G 3 ′ and the fourth lens group G 4 ′ (immediately in front of the fourth lens group G 4 ′). ‘I’ designates the imaging surface. 
         [0117]    In the zoom lens system of the sixth numerical embodiment, during zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the distance between the first lens group G 1 ′ and the second lens group G 2 ′ increases, the distance between the second lens group G 2 ′ and the third lens group G 3 ′ decreases, and the distance between the third lens group G 3 ′ and the fourth lens group G 4 ′ increases. 
         [0118]    More specifically, during zooming from the short focal length extremity to the long focal length extremity, the first lens group G 1 ′ and the fourth lens group G 4 ′ remain stationary relative to the imaging surface I, the second lens group G 2 ′ moves monotonically toward the image side, and the third lens group G 3 ′ moves monotonically toward the object side. Focusing is carried out by moving the first lens group G 1 ′ toward the object side. 
         [0119]    As shown in  FIG. 21 , the first lens group G 1 ′ is configured of a negative lens element  141 , a positive lens element  142 , a positive lens element  143 , a negative lens element  144  and a positive lens element  145 , in that order from the object side. The surface on the image side of the negative lens element  141  and the surface on the object side of the positive lens element  142  are cemented to each other. The surface on the image side of the positive lens element  143  and the surface on the object side of the negative lens element  144  are cemented to each other, and a diffraction surface DS which has a rotationally symmetric shape with respect to the optical axis is formed on the cemented surface thereof. 
         [0120]    The second lens group G 2 ′ is configured of a negative lens element  211 , a positive lens element  212 , a negative lens element  213 , a positive lens element  214  and a negative lens element  215 , in that order from the object side. The surface on the image side of the positive lens element  212  and the surface on the object side of the negative lens element  213  are cemented to each other. The surface on the image side of the positive lens element  214  and the surface on the object side of the negative lens element  215  are cemented to each other. 
         [0121]    The third lens group G 3 ′ is configured of a positive lens element  311 , a negative lens element  312 , a positive lens element  313  and a positive lens element  314 , in that order from the object side. The surface on the image side of the negative lens element  312  and the surface on the object side of the positive lens element  313  are cemented to each other. 
         [0122]    The fourth lens group G 4 ′ is configured of a positive lens element  441 , a positive lens element  442 , a negative lens element  443 , a positive lens element  444 , a positive lens element  445  and a negative lens element  446 , in that order from the object side. The surface on the image side of the positive lens element  445  and the surface on the object side of the negative lens element  446  are cemented to each other. 
         [0123]    In the seventh and eighth numerical embodiments, the zoom lens system is configured of a positive first lens group G 1 ″, a negative second lens group G 2 ″, a positive third lens group G 3 ″, a negative fourth lens group G 4 ″ and a positive first lens group G 5 ″ (five lens groups constituting a positive-negative-positive-negative-positive lens group configuration of a zoom lens system), in that order from the object side, as shown in the zoom paths of  FIGS. 47 and 48 . An aperture diaphragm S is positioned between the second lens group G 2 ″ and the third lens group G 3 ″ (immediately in front of the fourth lens group G 3 ″). ‘I’ designates the imaging surface. 
         [0124]    In the zoom lens system of the seventh numerical embodiment, during zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the distance between the first lens group G 1 ″ and the second lens group G 2 ″ increases, the distance between the second lens group G 2 ″ and the third lens group G 3 ″ decreases, the distance between the third lens group G 3 ″ and the fourth lens group G 4 ″ decreases, and the distance between the fourth lens group G 4 ″ and the fifth lens group G 5 ″ increases, as shown in the zoom path of  FIG. 47 . 
         [0125]    More specifically, during zooming from the short focal length extremity to the long focal length extremity, the first lens group G 1 ″, the third lens group G 3 ″ and the fifth lens group G 5 ″ remain stationary relative to the surface I, the second lens group G 2 ″ moves monotonically toward the image side, and the fourth lens group G 4 ″ first moves toward the image side and thereafter moves toward the object side until exceeding the position thereof when the fourth lens group G 4 ″ was at the short focal length extremity. Focusing is carried out by moving the fourth lens group G 4 ″ toward the image side. 
         [0126]    In the zoom lens system of the eighth numerical embodiment, during zooming from the short focal length extremity (Wide) to the long focal length extremity (Tele), the distance between the first lens group G 1 ″ and the second lens group G 2 ″ increases, the distance between the second lens group G 2 ″ and the third lens group G 3 ″ decreases, the distance between the third lens group G 3 ″ and the fourth lens group G 4 ″ increases, and the distance between the fourth lens group G 4 ″ and the fifth lens group G 5 ″ increases, as shown in the zoom path of  FIG. 48 . 
         [0127]    More specifically, during zooming from the short focal length extremity to the long focal length extremity, the fifth lens group G 5 ″ remains stationary relative to the imaging surface I, the first lens group G 1 ″ moves monotonically toward the object side, the second lens group G 2 ″ moves toward the image side while plotting a convex curve that faces the image side, the third lens group G 3 ″ moves monotonically toward the object side, and the fourth lens group G 4 ″ moves toward the object side while plotting a convex curve that faces the image side. Focusing is carried out by moving the fourth lens group G 4 ″ toward the image side. 
         [0128]    As shown in  FIGS. 25 and 29 , in the seventh and eighth embodiments, the first lens group G 1 ″ is configured of a negative lens element  151 , a positive lens element  152  and a positive lens element  153 , in that order from the object side. The surface on the image side of the negative lens element  151  and the surface on the object side of the positive lens element  152  are cemented to each other, and a diffraction surface DS which has a rotationally symmetric shape with respect to the optical axis is formed on the cemented surface thereof. 
         [0129]    As shown in  FIGS. 25 and 29 , in the seventh and eighth embodiments, the second lens group G 2 ″ is configured of a negative lens element  221 , a negative lens element  222 , a positive lens element  223  and a negative lens element  224 , in that order from the object side. The surface on the image side of the positive lens element  223  and the surface on the object side of the negative lens element  224  are cemented to each other. 
         [0130]    As shown in  FIGS. 25 and 29 , in the seventh and eighth embodiments, the third lens group G 3 ″ is configured of a positive lens element  321 , a positive lens element  322  and a negative lens element  323 , in that order from the object side. The surface on the image side of the positive lens element  322  and the surface on the object side of the negative lens element  323  are cemented to each other. 
         [0131]    As shown in  FIGS. 25 and 29 , in the seventh and eighth embodiments, the fourth lens group G 4 ″ is configured of a positive lens element  451  and a negative lens element  452 , in that order from the object side. The surface on the image side of the positive lens element  451  and the surface on the object side of the negative lens element  452  are cemented to each other. 
         [0132]    As shown in  FIG. 25 , in the seventh embodiment, the fifth lens group G 5 ″ is configured of a positive lens element  501 , a negative lens element  502  and a positive lens element  503 , in that order from the object side. 
         [0133]    As shown in  FIG. 29 , in the eighth embodiment, the fifth lens group G 5 ″ is configured of a positive lens element  511  and a negative lens element  512 , in that order from the object side. 
         [0134]    The zoom lens system, of the illustrated embodiments, is provided with at least a positive first lens group (G 1 , G 1 ′ or G 1 ″) and a negative second lens group (G 2 , G 2 ′ or G 2 ″), in that order from the object side, and by carrying out zooming by increasing the distance between the first lens group and the second lens group, the overall length of the lens system can be shortened and the configuration thereof is advantageous for achieving a high zoom ratio by increasing the focal length at the long focal-length side. Furthermore, by moving a greater number of lens elements within the zoom lens system increases the zooming efficiency, and further miniaturization and a higher zoom ratio become achievable. However, compared to the stationary lens groups that do not move during zooming, decentration easily occurs in the movable lens groups which move during zooming. Generally, in order to widen the angle-of-view of a positive-lead zoom lens system, the lens diameter of the first lens group tends to enlarge and the weight thereof increases, hence, decentration of the first lens group during zooming easily occurs. The decentration of the first lens group has an adverse influence mainly on aberrations at the telephoto side, and becomes a cause of deterioration in the optical quality. Therefore, in the first through seventh, ninth and tenth numerical embodiments of the present invention, in order to eliminate an adverse influences caused by decentration of the first lens group G 1 , the first lens group G 1  is made to remain stationary relative to the imaging surface I during zooming from the short focal length extremity to the long focal length extremity. 
         [0135]    In the zoom lens system of the illustrated embodiments, a diffraction surface DS which has a rotationally symmetric shape with respect to the optical axis is formed on the cemented surface of the cemented lens ( 101  and  102 ,  113  and  114 ,  121  and  122 ,  131  and  132 ,  143  and  144 , or  151  and  152 ) provided within the first lens group (G 1 , G 1 ′ or G 1 ″). Furthermore, due to the arrangement of the diffraction surface, by controlling the optical power, and by further selecting an optimum material, a superior optical quality has been successfully achieved in which chromatic aberration has been favorably corrected from the visible region to a near infra-red region over the entire zooming range. 
         [0136]      FIG. 49  shows the structure of the diffraction surface DS provided in the first lens group (G 1 , G 1 ′ or G 1 ″) and  FIGS. 50 and 51  show the diffraction efficiency thereof. As shown in  FIG. 49 , each cemented lens ( 101  and  102 ,  113  and  114 ,  121  and  122 ,  131  and  132 ,  143  and  144 , or  151  and  152 ) within the first lens group (G 1 , G 1 ′ or G 1 ″) is provided with a resin material RE 1  on a substrate glass BG 1  and a resin material RE 2  on a substrate glass BG 2 , and the diffraction surface DS is formed at the boundary surface between the resin material RE 1  and the resin material RE 2 . When the diffraction optical element is used, the light-quantity deterioration, at the design order, becomes flare due to the influence of the unwanted diffraction order. The ratio of the design-order diffracted light to the unwanted light relative to the total quantity of transmitted light is shown by the diffraction efficiency, and is characterized by being dependent on wavelength. The wavelength dependency of diffraction efficiency can be resolved by laminating two materials that have different refractive indexes and Abbe numbers. Hence, in the illustrated embodiments, the refractive index nd and the Abbe number νd of the resin material RE 1  (nd=1.61505, νd=26.5) is made to be different from the refractive index nd and the Abbe number νd of the resin material RE 2  (nd=1.64310, νd=38.8) and are cemented to each other; furthermore, in order to achieve a high diffraction efficiency from the visible light region through to the near infra-red region, the optimum wavelength is set to 670 nm and the grating thickness of the diffraction surface DS (the height of the steps in a direction parallel to the optical axis of the diffraction surface DS), indicated as ‘d’ in  FIG. 49 , is set to 22.4 μm. Furthermore, ‘P’ indicated in  FIG. 49  shows the grating pitch of the diffraction surface DS. 
         [0137]    The diffraction surface (diffraction lens surface) is shown by a macroscopic profile, indicated by the radius of curvature R, and by an optical path difference function defined by the following equation: 
         [0000]      Δø( h )=( P   2   h   2   +P   4   h   4 + . . . )λ, wherein
 
         [0138]    h designates the height from the optical axis, 
         [0139]    Pi designates an optical path difference function coefficient, and 
         [0140]    λ designates an arbitrary wavelength. 
         [0141]    Furthermore, the focal length fD of paraxial first order light (m=1) at the reference wavelength of the diffraction portion is represented by the following equation with the coefficient of the quadratic term from the previous equation (a), which indicates the phase of the diffraction portion: 
         [0000]        fD=− 1/(2× P   2 ×λ 0 ), wherein
 
         [0142]    λ 0  designates an arbitrary wavelength for calculating the power of the diffraction surface. In the conditions detailed below, λ 0  is set at the d-line (587.56 nm). 
         [0143]    In  FIG. 49 , ‘θ’ designates the angle between the optical axis and the principal rays, incident onto the diffraction surface DS that is formed on the cemented surface of the cemented lens provided within the first lens group (G 1 , G 1 ′ and G 1 ″) (the incident angle at the diffraction surface DS at the maximum image height), i.e., the diffraction surface incident angle (°). If the diffraction surface incident angle θ becomes large, flare easily occurs at the diffraction surface DS, and hence, it is desirable for the diffraction surface incident angle θ to be as small as possible. In case of the optical system of the illustrated embodiments, it is desirable for the diffraction surface incident angle θ to be 13° or less.  FIG. 50  shows the diffraction efficiency of the diffraction surface DS in the case where the diffraction surface incident angle θ is 0°, and  FIG. 51  shows the diffraction efficiency of the diffraction surface DS in the case where the diffraction surface incident angle θ is 13°.  FIGS. 50 and 51  show the case where the grating pitch P of the diffraction surface DS is 200 μm, the grating thickness d of the diffraction surface DS is 22.4 μm, the 1 st  order diffraction light is the design order, and the 0 th  order diffraction light and the 2 nd  order diffraction light as unwanted light (flare component). Upon comparing  FIG. 50  with  FIG. 51 , even if the diffraction surface incident angle θ changes from 0° to 13°, practically almost no change occurs in the diffraction efficiency therebetween. 
         [0144]    Furthermore, the zoom lens system of the illustrated embodiments can be provided with an insertable/removable extender (rear converter) in order to change the focal length of the entire lens system at the long focal length side to any position on the optical path (e.g., to double the focal length), as shown, e.g., in the Reference Example ( FIG. 41 ) which will be discussed later. 
         [0145]    Conditions (1) and (1′) specify the power of the diffraction surface DS that is provided within the first lens group (G 1 , G 1 ′ and G 1 ″). By satisfying condition (1), chromatic aberration can be favorably corrected from the visible region to the near infra-red region over the entire zooming range, and spherical aberration at mainly the long focal length extremity and coma, etc., can be favorably corrected, thereby achieving a superior optical quality. This effect is more noticeable if condition (1′) is satisfied. 
         [0146]    If the upper limit of condition (1) or (1′) is exceeded, the power of the diffraction surface DS becomes too weak, so that the chromatic aberration correction via the diffraction surface becomes insufficient. Furthermore, due to the radius of curvature of the substrate surface having the diffraction surface DS becoming small, it becomes difficult to correct spherical aberration, coma and chromatic aberration that occur mainly at the long focal length extremity. 
         [0147]    If the lower limit of condition (1) is exceeded, the power of the diffraction surface DS becomes too strong, so that the chromatic aberrations becomes over corrected. 
         [0148]    Condition (2) specifies the ratio of the focal length of the first lens group (G 1 , G 1 ′ or G 1 ″) to the focal length of the entire focal length at the long focal length extremity. By satisfying condition (2), the lens system can be miniaturized, lateral chromatic aberration, spherical aberration and coma, etc., can be favorably corrected, and a superior optical quality can be achieved. This effect is more prominent if condition (2′) is satisfied. 
         [0149]    If the upper limit of condition (2) is exceeded, the power of the first lens group becomes too weak, the overall length of the lens system increases, and the diameter of the frontmost lens element also becomes large. Accordingly, the paraxial light rays that pass through the first lens group increase in height, thereby worsening the lateral chromatic aberration at the short focal length extremity and the long focal length extremity. 
         [0150]    If the lower limit of condition (2′) is exceeded, the power of the first lens group becomes too strong, so that spherical aberration and coma, etc., worsen, mainly at the long focal length extremity. 
         [0151]    Condition (3) specifies the Abbe number at the d-line of the negative lens element provided within the first lens group (G 1 , G 1 ′ or G 1 ″). By providing a negative lens element having an Abbe number that satisfies condition (3) within the first lens group, lateral chromatic aberration at the short focal length extremity and axial chromatic aberration at the long focal length extremity can be favorably corrected, so that a superior optical quality can be achieved. 
         [0152]    If the lower limit of condition (3) is exceeded, lateral chromatic aberration at the short focal length extremity and axial chromatic aberration at the long focal length extremity become over corrected. 
         [0153]    Condition (4) specifies the partial dispersion ratio of the negative lens element provided in the first lens group (G 1 , G 1 ′ and G 1 ″). By providing a negative lens element having a partial dispersion ratio that satisfies condition (4) within the first lens group, axial chromatic aberration can be favorably corrected from the visible region to the near infra-red region at the long focal length extremity, so that a superior optical quality can be achieved. 
         [0154]    If the upper limit of condition (4) is exceeded, a secondary spectrum remains mainly at the long focal length side, so that correction of axial chromatic aberration from the visible region to the near infra-red region at the long focal length extremity becomes difficult. 
         [0155]    Furthermore, examples of glass materials that satisfy conditions (3) and (4) are, e.g., HOYA NBFD15 (νd=33.3, θgF=0.5883) produced by HOYA Corporation, and OHARA S-LAH60 (νd=37.2, θgF=0.5776) produced by OHARA Inc. 
         [0156]    Condition (5) specifies the Abbe number at the d-line of a positive lens element(s) provided within the first lens group (G 1 , G 1 ′ and G 1 ″). By providing a positive lens element(s) having an Abbe number that satisfies condition (5) within the first lens group, lateral chromatic aberration at the short focal length extremity and axial chromatic aberration at the long focal length extremity can be favorably corrected, so that a superior optical quality can be achieved. 
         [0157]    If the lower limit of condition (5) is exceeded, it becomes difficult to correct lateral chromatic aberration at the short focal length extremity and axial chromatic aberration at the long focal length extremity. 
         [0158]    Furthermore, examples of glass materials that satisfy condition (5) are, e.g., SUMITAK-GFK70 (νd=71.3, θgF=0.5450) produced by Sumita Optical Glass, Inc., and OHARA S-FPL51 (νd=81.6, θgF=0.5375) produced by OHARA Inc. 
         [0159]    Condition (6) specifies the ratio of the focal length of the first lens group (G 1 , G 1 ′ and G 1 ″) to the thickness of the first lens group (G 1 , G 1 ′ and G 1 ″). By satisfying condition (6), the lens system can be miniaturized, lateral chromatic aberration, spherical aberration and coma, etc., can be favorably corrected, and a superior optical quality can be achieved. 
         [0160]    If the upper limit of condition (6) is exceeded, the power of the first lens group becomes too weak, the entire length of the lens system becomes long, and the frontmost lens diameter becomes large. Accordingly, paraxial light rays passing through the first lens group increase in height, so that lateral chromatic aberration at the short focal length extremity and at the long focal length extremity worsen. 
         [0161]    If the lower limit of condition (6) is exceeded, the power of the first lens group becomes too strong, so that spherical aberration and coma, etc., worsen, mainly at the long focal length extremity. 
         [0162]    Condition (7) specifies the Abbe number at the d-line of the positive lens element provided within the second lens group (G 2 , G 2 ′ and G 2 ″). By providing a positive lens element that satisfies condition (7) within the second lens group, lateral chromatic aberration at the short focal length extremity can be favorably corrected and a superior optical quality can be achieved. 
         [0163]    If the upper limit of condition (7) is exceeded, it becomes difficult to correct lateral chromatic aberration mainly at the short focal length extremity. 
         [0164]    Furthermore, examples of glass materials that satisfy condition (7) are, e.g., OHARA S-NPH1 (νd=22.8, θgF=0.6307) produced by OHARA, Inc., and OHARA S-NPH2 (νd=18.9, θgF=0.6495). 
         [0165]    Condition (8) specifies the power of the second lens group (G 2 , G 2 ′ and G 2 ″). By satisfying condition (8), a high zoom ratio can be maintained while shortening the overall length of the lens system, and lateral chromatic aberration, field curvature and coma, etc., can be favorably corrected, so that a superior optical quality can be achieved. 
         [0166]    If the upper limit of condition (8) is exceeded, the power of the second lens group becomes too weak, so that if attempts are mode to maintain a high zoom ratio, the overall length of the lens system becomes long. Accordingly, the paraxial light rays that pass through the first lens group and the second lens group increase in height mainly at the short focal length extremity, and lateral chromatic aberration worsens. 
         [0167]    If the lower limit of condition (8) is exceeded, the power of the second lens group becomes too strong, so that positive field curvature occurs over the entire zooming range, and coma also worsens. 
         [0168]    Condition (9) specifies the lateral magnification of the stationary lens groups (the fourth lens group G 4 , the fourth lens group G 4 ′ and the fifth lens group G 5 ″) which remain stationary when zooming at a position closest to the image side. By satisfying condition (9), spherical aberration and coma at the short focal length extremity can be favorably corrected, and a superior optical quality can be achieved. 
         [0169]    If the upper limit of condition (9) is exceeded, the lateral magnification of the stationary lens group becomes too large, and spherical aberration and coma worsen mainly at the short focal length extremity. 
         [0170]    Condition (10) specifies the Abbe number at the d-line of the positive lens elements provided within the stationary lens groups (the fourth lens group G 4 , the fourth lens group G 4 ′ and the fifth lens group G 5 ″) which remain stationary when zooming at a position closest to the image side. By providing a positive lens element that satisfies condition (10) within the stationary lens group, axial chromatic aberration mainly at the short focal length extremity can be favorably corrected, thereby achieving a superior optical quality. 
         [0171]    If the lower limit of condition (10) is exceeded, axial chromatic aberration mainly at the short focal length extremity becomes difficult to correct. 
         [0172]    Furthermore, examples of glass materials that satisfy condition (10) are, e.g., SUMITA K-GFK70 (νd=71.3) produced by Sumita Optical Glass, Inc., and OHARA S-FPL51 (νd=81.6). 
         [0173]    As described above, in the first through fifth numerical embodiments, the third lens group G 3  has a negative refractive power. With this configuration, condition (11) specifies the ratio of the power of the negative second lens group to the power of the negative third lens group. By satisfying condition (11), a high zoom ratio is ensured while field curvature, coma and lateral chromatic aberration are favorably corrected, thereby achieving superior optical quality. 
         [0174]    If the upper limit of condition (11) is exceeded, the negative power of the third lens group G 3  becomes too strong, so that fluctuation in field curvature during zooming becomes large. 
         [0175]    If the lower limit of condition (11) is exceeded, the negative power of the third lens group G 3  becomes too weak, so that it becomes necessary to strengthen the negative power of the second lens group G 2  in order to attain a high zoom ratio, and correction of coma and lateral chromatic aberration over the entire zooming range becomes difficult. 
         [0176]    Conditions (12), (12′) and (12″) normalize the power of the diffraction surface DS using the power of the first lens group (G 1 , G 1 ′ and G 1 ″). By satisfying condition (12), various aberrations mainly at the long focal length extremity such as spherical aberration and coma, etc., can be favorably corrected, and a superior optical quality can be achieved. Furthermore, by satisfying conditions (12′) and (12″), axial chromatic aberration mainly at the long focal length extremity can be favorably corrected, thereby achieving a superior optical quality. 
         [0177]    If the lower limit of conditions (12) and (12′) are exceeded, the power of the diffraction DS becomes too strong, so that axial chromatic aberration mainly at the long focal length extremity becomes over corrected. 
         [0178]    If the upper limit of conditions (12′) and (12″) are exceeded, the power of the diffraction surface DS becomes too weak, so that correction of axial chromatic aberration mainly at the long focal length extremity becomes insufficient. 
         [0179]    Condition (13) specifies the partial dispersion ratio and the Abbe number at the d-line of the positive lens elements provided within the first lens group (G 1 , G 1 ′ and G 1 ″). By satisfying condition (13), mainly at the long focal length extremity, a secondary spectrum can be prevented from remaining while favorably correcting axial chromatic aberration at the g-line and chromatic aberration in the visible region, so that a superior optical quality can be achieved. 
         [0180]    If the lower limit of condition (13) is exceeded, mainly at the long focal length extremity, a secondary spectrum remains, axial chromatic aberration at the g-line becomes over corrected, and chromatic aberration in the visible region worsens. 
         [0181]    Condition (14) specifies the partial dispersion ratio and the Abbe number at the d-line of the positive lens elements provided within the second lens group (G 2 , G 2 ′ and G 2 ″). By satisfying condition (14), with respect to mainly at the long focal length extremity, a secondary spectrum can be prevented from remaining while favorably correcting axial chromatic aberration at the g-line and chromatic aberration in the visible region, so that a superior optical quality can be achieved. 
         [0182]    If the lower limit of condition (14) is exceeded, with respect to mainly at the long focal length extremity, a secondary spectrum remains, axial chromatic aberration at the g-line becomes over corrected and chromatic aberration in the visible region worsens. 
         [0183]    Conditions (15) and (15′) normalize the power of the diffraction surface DS provided within the first lens group (G 1 , G 1 ′ and G 1 ″) using the focal length of the entire lens system at the long focal length extremity. By satisfying condition (15), axial chromatic aberration mainly at the long focal length extremity can be favorably corrected, so that a superior optical quality can be achieved. 
         [0184]    If the lower limits of conditions (15) and (15′) are exceeded, the power of the diffraction surface DS becomes too strong, so that axial chromatic aberration mainly at the long focal length extremity becomes over corrected. 
         [0185]    If the upper limit of condition (15′) is exceeded, the power of the diffraction surface DS becomes too weak, so that correction of axial chromatic aberration mainly at the long focal length extremity becomes insufficient. 
         [0186]    As described above, in the first through fifth, ninth and tenth numerical embodiments, the second lens group G 2  is configured of a negative lens element  201 , and a cemented lens having a positive lens element  202  and a negative lens element  203 , in that order from the object side. 
         [0187]    With this configuration, condition (16) specifies the profile (shape factor) of the negative lens element  201  which is provided closest to the object side within the second lens group G 2 . By satisfying condition (16), spherical aberration mainly at the long focal length extremity can be favorably corrected, so that a superior optical quality can be achieved. 
         [0188]    If the upper limit of condition (16) is exceeded, the radius of curvature of the concave surface on the object side of the negative lens element  201  becomes too large, and spherical aberration remaining in the first lens group G 1  becomes difficult to correct, so that correction of spherical aberration mainly at the long focal length extremity becomes insufficient. 
         [0189]    If the lower limit of condition (16) is exceeded, the radius of curvature of the concave surface on the object side of the negative lens element  201  becomes too small, so that spherical aberration mainly at the long focal length extremity becomes over corrected. 
       EMBODIMENTS 
       [0190]    Specific first through tenth numerical embodiments will be herein discussed. In the various aberration diagrams and the tables, S designates the sagittal image, M designates the meridional image, FNO. designates the f-number, f designates the focal length of the entire optical system, W designates the half angle of view (°), Y designates the image height, fB designates the backfocus, L designates the overall length of the lens system, R designates the radius of curvature, d designates the lens thickness or distance between lenses, N(d) designates the refractive index at the d-line, ν(d) designates the Abbe number with respect to the d-line, and θgF indicates a partial dispersion ratio. Furthermore, the diffraction surface incidence angle (°) refers to the angle between each principal ray, which is incident on the diffraction surface DS formed on the cemented surface of the cemented lens provided within the first lens group (G 1 , G 1 ′ and G 1 ″), and the optical axis (the incident angle at the diffraction surface at a maximum image height). The values for the f-number, the focal length, the half angle-of-view, the image height, the backfocus, the overall length of the lens system, the distance d between lenses (which changes during zooming), and the diffraction surface incident angle (°) are shown in the following order: short focal length extremity, intermediate focal length, and long focal length extremity. The unit used for lengths is defined in millimeters (mm). 
       Numerical Embodiment 1 
       [0191]      FIGS. 1 through 4  and Tables 1 through 3 show a first numerical embodiment of the zoom lens system according to the present invention.  FIG. 1  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 2 ,  3  and  4  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 1 shows the lens surface data, Table 2 shows various lens-system data, and Table 3 shows the lens group data. 
         [0192]    The zoom lens system of the first numerical embodiment is configured of a positive first lens group G 1 , a negative second lens group G 2 , a negative third lens group G 3  and a positive fourth lens group G 4 , in that order from the object side (four lens groups constituting a positive-negative-negative-positive lens group configuration of a zoom lens system). An ND filter ND for light-quantity adjustment and an aperture diaphragm S are provided, in that order from the object side, between the third lens group G 3  and the fourth lens group G 4  (immediately in front of the fourth lens group G 4 ). A protective glass (cover glass) CG for protecting the imaging surface I is provided between the fourth lens group G 4  and the imaging surface I. 
         [0193]    The first lens group G 1  is configured of a negative meniscus lens element  101  having a convex surface on the object side, a biconvex positive lens element  102  and a biconvex positive lens element  103 , in that order from the object side. The surface on the image side of the negative meniscus lens element  101  and the surface on the object side of the biconvex positive lens element  102  are cemented to each other, and the diffraction surface DS, which has a rotationally symmetric shape with respect to the optical axis, is formed on the cemented surface thereof. 
         [0194]    The second lens group G 2  is configured of a biconcave negative lens element  201 , a biconvex positive lens element  202  and a biconcave negative lens element  203 , in that order from the object side. The surface on the image side of the biconvex positive lens element  202  and the surface on the object side of the biconcave negative lens element  203  are cemented to each other. 
         [0195]    The third lens group G 3  is configured of a biconcave negative lens element  301  and a positive meniscus lens element  302  having a convex surface on the object side, in that order from the object side. The surface on the image side of the biconcave negative lens element  301  and the surface on the object side of the positive meniscus lens element  302  are cemented to each other. 
         [0196]    The fourth lens group G 4  is configured of a biconvex positive lens element  401 , a biconvex positive lens element  402 , a negative meniscus lens element  403  having a convex surface on the image side, a biconvex positive lens element  404  and a negative meniscus lens element  405  having a convex surface on the object side, in that order from the object side. The surface on the image side of the biconvex positive lens element  402  and the surface on the object side of the negative meniscus lens element  403  are cemented to each other. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
           
               
                 TABLE 1 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν(d) 
                 θgF 
               
               
                   
               
               
                  1 
                 216.879 
                 2.650 
                 1.78590 
                 44.2 
                 0.5631 
               
               
                  2 
                 100.172 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  3* 
                 100.172 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  4 
                 100.172 
                 14.582  
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  5 
                 −997.512 
                 0.200 
               
               
                  6 
                 98.849 
                 13.037  
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  7 
                 −11842.277 
                 d7 
               
               
                  8 
                 −200.974 
                 2.000 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                  9 
                 1582.645 
                 0.720 
               
               
                 10 
                 155.877 
                 8.170 
                 1.80810 
                 22.8 
                 0.6307 
               
               
                 11 
                 −102.601 
                 2.000 
                 1.77250 
                 49.6 
                 0.5503 
               
               
                 12 
                 51.953 
                 d12 
               
               
                 13 
                 −68.946 
                 1.200 
                 1.69680 
                 55.5 
                 0.5425 
               
               
                 14 
                 15.570 
                 3.290 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 15 
                 38.015 
                 d15 
               
               
                 16 
                 ∞ 
                 1.000 
                 1.51680 
                 64.2 
                 0.5343 
               
               
                 17 
                 ∞ 
                 0.900 
               
               
                 18(Diaphragm) 
                 ∞ 
                 2.500 
               
               
                 19 
                 87.428 
                 3.260 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 20 
                 −91.053 
                 0.100 
               
               
                 21 
                 176.868 
                 5.810 
                 1.59522 
                 67.7 
                 0.5442 
               
               
                 22 
                 −23.802 
                 1.800 
                 1.79952 
                 42.2 
                 0.5672 
               
               
                 23 
                 −270.286 
                 4.940 
               
               
                 24 
                 56.038 
                 5.520 
                 1.59522 
                 67.7 
                 0.5442 
               
               
                 25 
                 −71.458 
                 0.200 
               
               
                 26 
                 31.951 
                 3.000 
                 1.69680 
                 55.5 
                 0.5425 
               
               
                 27 
                 23.069 
                 78.760  
               
               
                 28 
                 ∞ 
                 3.500 
                 1.51680 
                 64.2 
                 0.5343 
               
               
                 29 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −8.69915E−04 
                 P4 = 8.18449E−07 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative lens element 101 
               
               
                   
               
               
                 θgF = 0.5631 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 2 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 38.82 
               
             
          
           
               
                   
                   
                   
                 Long 
               
               
                   
                 Short Focal Length 
                 Intermediate 
                 Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
               
             
          
           
               
                 FNO. 
                 4.0 
                 4.0 
                 7.2 
               
               
                 f 
                 17.00 
                 105.90 
                 660.00 
               
               
                 W 
                 15.6 
                 2.4 
                 0.4 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 368.47 
                 368.47 
                 368.47 
               
               
                 d7 
                 4.471 
                 107.944 
                 131.626 
               
               
                 d12 
                 150.272 
                 51.766 
                 73.000 
               
               
                 d15 
                 53.391 
                 48.424 
                 3.507 
               
               
                 Diffraction Surface 
                 11.98 
                 3.90 
                 0.78 
               
               
                 Incidence Angle (°) 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 197.83 
               
               
                 2 
                 8 
                 −71.22 
               
               
                 3 
                 13 
                 −40.80 
               
               
                 4 
                 16 
                 48.11 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 2 
       [0197]      FIGS. 5 through 8  and Tables 4 through 6 show a second numerical embodiment of the zoom lens system according to the present invention.  FIG. 5  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 6 ,  7  and  8  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 4 shows the lens surface data, Table 5 shows various lens-system data, and Table 6 shows the lens group data. 
         [0198]    The lens arrangement of the second numerical embodiment is the same as that of the first numerical embodiment except for the following: 
         [0199]    (1) The first lens group G 1  is configured of a negative meniscus lens element  111  having a convex surface on the object side, a biconvex positive lens element  112 , a negative meniscus lens element  113  having a convex surface on the object side, a positive meniscus lens element  114  having a convex surface on the object side, and a biconvex positive lens element  115 , in that order from the object side. The surface on the image side of the negative meniscus lens element  111  and the surface on the object side of the biconvex positive lens element  112  are cemented to each other. The surface on the image side of the negative meniscus lens element  113  and the surface on the object side of the positive meniscus lens element  114  are cemented to each other, and the diffraction surface DS, which has a rotationally symmetric shape with respect to the optical axis, is formed on the cemented surface thereof. 
         [0200]    (2) The fourth lens group G 4  is configured of a biconvex positive lens element  411 , a biconvex positive lens element  412 , a biconvex positive lens element  413 , a biconcave negative lens element  414 , a positive meniscus lens element  415  having a convex surface on the object side, and a negative meniscus lens element  416  having a convex surface on the object side, in that order from the object side. The surface on the image side of the biconvex positive lens element  413  and the surface on the object side of the biconcave negative lens element  414  are cemented to each other. 
         [0201]    (3) An aperture diaphragm S and an ND filter ND for light-quantity adjustment are provided, in that order from the object side, between the third lens group G 3  and the fourth lens group G 4  (immediately in front of the fourth lens group G 4 ). 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
           
               
                 TABLE 4 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν(d) 
                 θgF 
               
               
                   
               
               
                  1 
                 1170.022 
                 3.000 
                 1.73400 
                 51.5 
                 0.5486 
               
               
                  2 
                 115.198 
                 22.417 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                  3 
                 −567.926 
                 2.871 
               
               
                  4 
                 211.429 
                 2.000 
                 1.45600 
                 91.4 
                 0.5342 
               
               
                  5 
                 95.104 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  6* 
                 95.104 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  7 
                 95.104 
                 19.649 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  8 
                 683.806 
                 0.328 
               
               
                  9 
                 111.223 
                 16.499 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 10 
                 −1357.053 
                 d10 
               
               
                 11 
                 −777.257 
                 2.583 
                 1.80100 
                 35.0 
                 0.5864 
               
               
                 12 
                 57.023 
                 16.039 
               
               
                 13 
                 251.491 
                 8.123 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 14 
                 −115.994 
                 4.522 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 15 
                 444.629 
                 d15 
               
               
                 16 
                 −44.341 
                 2.151 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 17 
                 15.146 
                 2.821 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 18 
                 29.354 
                 d18 
               
               
                 19(Diaphragm) 
                 ∞ 
                 0.600 
               
               
                 20 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 21 
                 ∞ 
                 2.200 
               
               
                 22 
                 59.748 
                 5.514 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 23 
                 −61.522 
                 0.100 
               
               
                 24 
                 48.537 
                 4.434 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 25 
                 −482.217 
                 0.100 
               
               
                 26 
                 40.828 
                 6.240 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 27 
                 −40.978 
                 2.200 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 28 
                 41.023 
                 4.853 
               
               
                 29 
                 26.546 
                 8.355 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 30 
                 519.733 
                 0.100 
               
               
                 31 
                 38.524 
                 2.770 
                 1.69350 
                 53.2 
                 0.5473 
               
               
                 32 
                 17.200 
                 53.146 
               
               
                 33 
                 ∞ 
                 3.500 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 34 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 6 
                 P2 = −9.55455E−04 
                 P4 = 9.22081E−07 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative lens element 111 
               
               
                 θgF = 0.5486 
               
               
                 Partial Dispersion Ratio for Negative lens element 113 
               
               
                 θgF = 0.5342 
               
               
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 5 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 58.22 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 4.0 
                 4.0 
                 8.2 
               
               
                 f 
                 14.60 
                 111.40 
                 850.00 
               
               
                 W 
                 17.9 
                 2.3 
                 0.3 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 394.41 
                 394.41 
                 394.41 
               
               
                 d10 
                 4.640 
                 120.268 
                 135.139 
               
               
                 d15 
                 118.095 
                 10.459 
                 55.986 
               
               
                 d18 
                 72.358 
                 64.366 
                 3.969 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 15.51 
                 6.04 
                 1.12 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 196.49 
               
               
                 2 
                 11 
                 −83.28 
               
               
                 3 
                 16 
                 −34.11 
               
               
                 4 
                 19 
                 44.38 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 3 
       [0202]      FIGS. 9 through 12  and Tables 7 through 9 show a third numerical embodiment of the zoom lens system according to the present invention.  FIG. 9  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 10 ,  11  and  12  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 7 shows the lens surface data, Table 8 shows various lens-system data, and Table 9 shows the lens group data. 
         [0203]    The lens arrangement of the third numerical embodiment is the same as that of the second numerical embodiment except for the following: 
         [0204]    (1) The first lens group G 1  is configured of a biconcave negative lens element  121 , a biconvex positive lens element  122 , a positive meniscus lens element  123  having a convex surface on the object side, and a positive meniscus lens element  124  having a convex surface on the object side, in that order from the object side. The surface on the image side of the biconcave negative lens element  121  and the surface on the object side of the biconvex positive lens element  122  are cemented to each other, and the diffraction surface DS, which has a rotationally symmetric shape with respect to the optical axis, is formed on the cemented surface thereof. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 −1428.542 
                 3.000 
                 1.63854 
                 55.4 
                 0.5484 
               
               
                  2 
                 120.918 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  3* 
                 120.918 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  4 
                 120.918 
                 19.289 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  5 
                 −306.976 
                 0.200 
               
               
                  6 
                 123.470 
                 16.296 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  7 
                 11138.787 
                 0.200 
               
               
                  8 
                 133.828 
                 10.261 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  9 
                 358.432 
                 d9 
               
               
                 10 
                 −777.257 
                 2.583 
                 1.80100 
                 35.0 
                 0.5864 
               
               
                 11 
                 57.023 
                 16.039 
               
               
                 12 
                 251.491 
                 8.123 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 13 
                 −115.994 
                 4.522 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 14 
                 444.629 
                 d14 
               
               
                 15 
                 −44.341 
                 2.151 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 16 
                 15.146 
                 2.821 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 17 
                 29.354 
                 d17 
               
               
                 18(Diaphragm) 
                 ∞ 
                 0.600 
               
               
                 19 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 20 
                 ∞ 
                 2.200 
               
               
                 21 
                 59.748 
                 5.514 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 22 
                 −61.522 
                 0.100 
               
               
                 23 
                 48.537 
                 4.434 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 24 
                 −482.217 
                 0.100 
               
               
                 25 
                 40.828 
                 6.240 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 26 
                 −40.978 
                 2.200 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 27 
                 41.023 
                 4.853 
               
               
                 28 
                 26.546 
                 8.355 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 29 
                 519.733 
                 0.100 
               
               
                 30 
                 38.524 
                 2.770 
                 1.69350 
                 53.2 
                 0.5473 
               
               
                 31 
                 17.200 
                 53.151 
               
               
                 32 
                 ∞ 
                 3.500 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 33 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −3.21564E−03 
                 P4 = 8.26001E−07 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 121 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5484 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 8 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 58.62 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 4.0 
                 4.0 
                 8.5 
               
               
                 f 
                 14.50 
                 111.00 
                 850.00 
               
               
                 W 
                 18.2 
                 2.3 
                 0.3 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 377.10 
                 377.10 
                 377.10 
               
               
                 d9 
                 4.909 
                 121.462 
                 136.468 
               
               
                 d14 
                 118.025 
                 9.453 
                 55.122 
               
               
                 d17 
                 72.359 
                 64.377 
                 3.702 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 10.14 
                 0.52 
                 0.03 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 9 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 196.52 
               
               
                 2 
                 10 
                 −83.28 
               
               
                 3 
                 15 
                 −34.11 
               
               
                 4 
                 18 
                 44.38 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 4 
       [0205]      FIGS. 13 through 16  and Tables 10 through 12 show a fourth numerical embodiment of the zoom lens system according to the present invention.  FIG. 13  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 14 ,  15  and  16  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 10 shows the lens surface data, Table 11 shows various lens-system data, and Table 12 shows the lens group data. 
         [0206]    The lens arrangement of the fourth numerical embodiment is the same as that of the first numerical embodiment except for the following: 
         [0207]    (1) The first lens group G 1  is configured of a negative meniscus lens element  121  having a convex surface on the object side, a biconvex positive lens element  122 , a positive meniscus lens element  123  having a convex surface on the object side, and a positive meniscus lens element  114  having a convex surface on the object side, in that order from the object side. The surface on the image side of the negative meniscus lens element  121  and the surface on the object side of the biconvex positive lens element  122  are cemented to each other, and the diffraction surface DS, which has a rotationally symmetric shape with respect to the optical axis, is formed on the cemented surface thereof. 
         [0208]    (2) The fourth lens group G 4  is configured of a biconvex positive lens element  421 , a biconvex positive lens element  422 , a negative meniscus lens element  423  having a convex surface on the image side, a positive meniscus lens element  424  having a convex surface on the object side, a negative meniscus lens element  425  having a convex surface on the object side, a negative meniscus lens element  426  having a convex surface on the object side, and a biconvex positive lens element  427 , in that order from the object side. The surface on the image side of the biconvex positive lens element  422  and the surface on the object side of the negative meniscus lens element  423  are cemented to each other. The surface on the image side of the negative meniscus lens element  426  and the surface on the object side of the biconvex positive lens element  427  are cemented to each other. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 10 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 12507.133 
                 3.500 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                  2 
                 209.485 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  3* 
                 209.485 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  4 
                 209.485 
                 16.401 
                 1.56908 
                 71.3 
                 0.5450 
               
               
                  5 
                 −425.363 
                 0.200 
               
               
                  6 
                 175.768 
                 13.241 
                 1.48749 
                 70.2 
                 0.5300 
               
               
                  7 
                 863.889 
                 0.200 
               
               
                  8 
                 121.699 
                 10.144 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                  9 
                 290.106 
                 d9 
               
               
                 10 
                 −185.266 
                 2.406 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 11 
                 105.189 
                 1.244 
               
               
                 12 
                 160.877 
                 6.223 
                 1.95906 
                 17.5 
                 0.6598 
               
               
                 13 
                 −87.492 
                 1.521 
                 1.79952 
                 42.2 
                 0.5672 
               
               
                 14 
                 41.161 
                 d14 
               
               
                 15 
                 −47.635 
                 1.615 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 16 
                 19.338 
                 3.423 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 17 
                 41.155 
                 d17 
               
               
                 18 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 19 
                 ∞ 
                 0.900 
               
               
                 20(Diaphragm) 
                 ∞ 
                 2.200 
               
               
                 21 
                 273.011 
                 5.358 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 22 
                 −63.836 
                 0.100 
               
               
                 23 
                 64.502 
                 7.466 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 24 
                 −47.586 
                 2.424 
                 1.80400 
                 46.6 
                 0.5573 
               
               
                 25 
                 −117.919 
                 0.200 
               
               
                 26 
                 37.547 
                 6.000 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 27 
                 236.611 
                 5.615 
               
               
                 28 
                 79.896 
                 2.424 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 29 
                 33.393 
                 3.818 
               
               
                 30 
                 132.347 
                 2.000 
                 1.72916 
                 54.7 
                 0.5444 
               
               
                 31 
                 41.081 
                 6.500 
                 1.59522 
                 67.7 
                 0.5442 
               
               
                 32 
                 −810.124 
                 85.529 
               
               
                 33 
                 ∞ 
                 3.500 
                 1.51680 
                 64.2 
                 0.5343 
               
               
                 34 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −2.93073E−02 
                 P4 = 6.07486E−08 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative lens element 121 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5883 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 11 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 101.19 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 4.0 
                 4.0 
                 12.1 
               
               
                 f 
                 12.60 
                 126.70 
                 1275.00 
               
               
                 W 
                 20.8 
                 2.0 
                 0.2 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 403.09 
                 403.09 
                 403.09 
               
               
                 d9 
                 4.517 
                 124.968 
                 149.245 
               
               
                 d14 
                 138.459 
                 17.043 
                 55.474 
               
               
                 d17 
                 63.767 
                 64.732 
                 2.024 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 11.74 
                 0.27 
                 0.05 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 12 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 197.32 
               
               
                 2 
                 10 
                 −40.33 
               
               
                 3 
                 15 
                 −43.33 
               
               
                 4 
                 18 
                 54.68 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 5 
       [0209]      FIGS. 17 through 20  and Tables 13 through 15 show a fifth numerical embodiment of the zoom lens system according to the present invention.  FIG. 17  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 18 ,  19  and  20  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 13 shows the lens surface data, Table 14 shows various lens-system data, and Table 15 shows the lens group data. 
         [0210]    The lens arrangement of the fifth numerical embodiment is the same as that of the first numerical embodiment except for the following: 
         [0211]    (1) The first lens group G 1  is configured of a positive meniscus lens element  131  having a convex surface on the object side, a biconvex positive lens element  132 , a positive meniscus lens element  133  having a convex surface on the object side, a positive meniscus lens element  134  having a convex surface on the object side, and a negative meniscus lens element  135  having a convex surface on the object side, in that order from the object side. The surface on the image side of the positive meniscus lens element  131  and the surface on the object side of the biconvex positive lens element  132  are cemented to each other, and the diffraction surface DS, which has a rotationally symmetric shape with respect to the optical axis, is formed on the cemented surface thereof. 
         [0212]    (2) The fourth lens group G 4  is configured of a biconvex positive lens element  431 , a biconvex positive lens element  432 , a biconvex positive lens element  433 , a negative meniscus lens element  434  having a convex surface on the image side, a positive meniscus lens element  435  having a convex surface on the object side, a negative meniscus lens element  436  having a convex surface on the object side, and a biconvex positive lens element  437 , in that order from the object side. The surface on the image side of the biconvex positive lens element  433  and the surface on the object side of the negative meniscus lens element  434  are cemented to each other. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 13 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 140.156 
                 10.239 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                  2 
                 249.156 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  3* 
                 249.156 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  4 
                 249.156 
                 11.700 
                 1.48749 
                 70.2 
                 0.5300 
               
               
                  5 
                 −1952.193 
                 0.200 
               
               
                  6 
                 105.524 
                 18.569 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  7 
                 751.164 
                 0.200 
               
               
                  8 
                 86.578 
                 16.823 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  9 
                 901.830 
                 0.898 
               
               
                 10 
                 2113.286 
                 3.500 
                 1.80440 
                 39.6 
                 0.5729 
               
               
                 11 
                 85.931 
                 d11 
               
               
                 12 
                 −150.360 
                 2.406 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 13 
                 128.035 
                 2.915 
               
               
                 14 
                 188.504 
                 6.223 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 15 
                 −59.693 
                 1.521 
                 1.79952 
                 42.2 
                 0.5672 
               
               
                 16 
                 39.466 
                 d16 
               
               
                 17 
                 −47.171 
                 1.615 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 18 
                 17.286 
                 3.423 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 19 
                 35.448 
                 d19 
               
               
                 20 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 21 
                 ∞ 
                 0.900 
               
               
                 22(Diaphragm) 
                 ∞ 
                 2.200 
               
               
                 23 
                 83.109 
                 5.358 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 24 
                 −89.484 
                 0.100 
               
               
                 25 
                 197.473 
                 5.300 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 26 
                 −69.953 
                 0.100 
               
               
                 27 
                 105.698 
                 7.466 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 28 
                 −42.842 
                 2.424 
                 1.80400 
                 46.6 
                 0.5573 
               
               
                 29 
                 −441.050 
                 0.200 
               
               
                 30 
                 36.929 
                 6.000 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 31 
                 87.603 
                 5.615 
               
               
                 32 
                 172.522 
                 2.424 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 33 
                 38.879 
                 77.114 
               
               
                 34 
                 79.365 
                 4.128 
                 1.72916 
                 54.7 
                 0.5444 
               
               
                 35 
                 −250.015 
                 27.782 
               
               
                 36 
                 ∞ 
                 3.500 
                 1.51680 
                 64.2 
                 0.5343 
               
               
                 37 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −2.37752E−02 
                 P4 = 3.33275E−07 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 135 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5729 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 14 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 57.95 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 3.7 
                 3.7 
                 12.1 
               
               
                 f 
                 22.00 
                 167.50 
                 1275.00 
               
               
                 W 
                 11.7 
                 1.5 
                 0.2 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 383.60 
                 383.60 
                 383.60 
               
               
                 d11 
                 5.515 
                 82.738 
                 97.471 
               
               
                 d16 
                 78.600 
                 5.460 
                 50.118 
               
               
                 d19 
                 66.444 
                 62.361 
                 2.971 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 12.52 
                 5.13 
                 0.14 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 15 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 194.65 
               
               
                 2 
                 12 
                 −37.79 
               
               
                 3 
                 17 
                 −39.68 
               
               
                 4 
                 20 
                 144.78 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 6 
       [0213]      FIGS. 21 through 24  and Tables 16 through 18 show a sixth numerical embodiment of the zoom lens system according to the present invention.  FIG. 21  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 22 ,  23  and  24  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 16 shows the lens surface data, Table 17 shows various lens-system data, and Table 18 shows the lens group data. 
         [0214]    The lens arrangement of the sixth numerical embodiment differs overall from that of the first through fifth numerical embodiments. 
         [0215]    (1) The zoom lens system is configured of a positive first lens group G 1 ′, a negative second lens group G 2 ′, a positive third lens group G 3 ′ and a negative fourth lens group G 4 ′, in that order from the object side (four lens groups constituting a positive-negative-positive-negative lens group configuration of a zoom lens system). 
         [0216]    (2) The first lens group G 1 ′ is configured of a negative meniscus lens element  141  having a convex surface on the object side, a biconvex positive lens element  142 , a biconvex positive lens element  143 , a negative meniscus lens element  144  having a convex surface on the image side, and a biconvex positive lens element  145 , in that order from the object side. The surface on the image side of the negative meniscus lens element  141  and the surface on the object side of the biconvex positive lens element  142  are cemented to each other. The surface on the image side of the biconvex positive lens element  143  and the surface on the object side of the negative meniscus lens element  144  are cemented to each other, and the diffraction surface DS, which has a rotationally symmetric shape with respect to the optical axis, is formed on the cemented surface. 
         [0217]    (3) The second lens group G 2 ′ is configured of a negative meniscus lens element  211  having a convex surface on the object side, a biconvex positive lens element  212 , a biconcave negative lens element  213 , a positive meniscus lens element  214  having a convex surface on the image side, and a biconcave negative lens element  215 , in that order from the object side. The surface on the image side of the biconvex positive lens element  212  and the surface on the object side of the biconcave negative lens element  213  are cemented to each other. The surface on the image side of the positive meniscus lens element  214  and the surface on the object side of the biconcave negative lens element  215  are cemented to each other. 
         [0218]    (4) The third lens group G 3 ′ is configured of a biconvex positive lens element  311 , a negative meniscus lens element  312  having a convex surface on the object side, a biconvex positive lens element  313 , and a positive meniscus lens element  314  having a convex surface on the object side, in that order from the object side. The surface on the image side of the negative meniscus lens element  312  and the surface on the object side of the biconvex positive lens element  313  are cemented to each other. 
         [0219]    (5) The fourth lens group G 4 ′ is configured of a positive meniscus lens element  441  having a convex surface on the object side, a positive meniscus lens element  442  having a convex surface on the object side, a biconcave negative lens element  443 , a biconvex positive lens element  444 , a biconvex positive lens element  445 , and a biconcave negative lens element  446 , in that order from the object side. The surface on the image side of the biconvex positive lens element  445  and the surface on the object side of the biconcave negative lens element  446  are cemented to each other. 
         [0220]    (6) An aperture diaphragm S and an ND filter ND for light-quantity adjustment are provided, in that order from the object side, between the third lens group G 3 ′ and the fourth lens group G 4 ′ (immediately in front of the fourth lens group G 4 ). 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 16 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 479.909 
                 3.100 
                 2.00100 
                 29.1 
                 0.5994 
               
               
                  2 
                 113.923 
                 17.305 
                 1.61293 
                 37.0 
                 0.5849 
               
               
                  3 
                 −10395.997 
                 0.500 
               
               
                  4 
                 623.352 
                 15.390 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  5 
                 −188.916 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  6* 
                 −188.916 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  7 
                 −188.916 
                 3.200 
                 1.45600 
                 91.4 
                 0.5342 
               
               
                  8 
                 −421.984 
                 0.200 
               
               
                  9 
                 109.983 
                 19.387 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 10 
                 −1324.776 
                 d10 
               
               
                 11 
                 241.137 
                 1.304 
                 1.88300 
                 40.8 
                 0.5667 
               
               
                 12 
                 65.390 
                 6.000 
               
               
                 13 
                 71.470 
                 4.303 
                 1.84666 
                 23.8 
                 0.6205 
               
               
                 14 
                 −62.894 
                 1.700 
                 1.80440 
                 39.6 
                 0.5729 
               
               
                 15 
                 41.260 
                 4.174 
               
               
                 16 
                 −38.191 
                 3.214 
                 1.80810 
                 22.8 
                 0.6307 
               
               
                 17 
                 −26.595 
                 1.200 
                 1.69350 
                 53.2 
                 0.5473 
               
               
                 18 
                 3739.624 
                 d18 
               
               
                 19 
                 87.056 
                 4.856 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 20 
                 −105.693 
                 0.120 
               
               
                 21 
                 86.016 
                 2.791 
                 1.83400 
                 37.3 
                 0.5789 
               
               
                 22 
                 40.082 
                 5.792 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 23 
                 −1337.427 
                 0.120 
               
               
                 24 
                 78.564 
                 4.266 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 25 
                 219.099 
                 d25 
               
               
                 26(Diaphragm) 
                 ∞ 
                 0.600 
               
               
                 27 
                 ∞ 
                 1.000 
                 1.51680 
                 64.2 
                 0.5343 
               
               
                 28 
                 ∞ 
                 1.033 
               
               
                 29 
                 47.481 
                 2.891 
                 1.80440 
                 39.6 
                 0.5729 
               
               
                 30 
                 64.977 
                 1.782 
               
               
                 31 
                 23.875 
                 3.829 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 32 
                 47.049 
                 1.708 
               
               
                 33 
                 −383.102 
                 1.200 
                 1.72916 
                 54.7 
                 0.5444 
               
               
                 34 
                 28.455 
                 26.195 
               
               
                 35 
                 158.309 
                 3.821 
                 1.88300 
                 40.8 
                 0.5667 
               
               
                 36 
                 −35.161 
                 0.532 
               
               
                 37 
                 29.791 
                 4.660 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 38 
                 −22.176 
                 1.200 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 39 
                 20.632 
                 36.857 
               
               
                 40 
                 ∞ 
                 3.500 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 41 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 6 
                 P2 = −3.24379E−02 
                 P4 = −7.15880E−07 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 144 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5342 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 17 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 51.52 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 4.0 
                 5.2 
                 8.1 
               
               
                 f 
                 16.50 
                 118.40 
                 850.00 
               
               
                 W 
                 15.1 
                 2.1 
                 0.3 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 414.39 
                 414.39 
                 414.39 
               
               
                 d10 
                 4.598 
                 91.625 
                 118.420 
               
               
                 d18 
                 215.004 
                 97.816 
                 5.118 
               
               
                 d25 
                 3.856 
                 34.017 
                 99.920 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 7.88 
                 0.10 
                 0.10 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 18 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 176.64 
               
               
                 2 
                 11 
                 −27.98 
               
               
                 3 
                 19 
                 68.76 
               
               
                 4 
                 26 
                 −214.82 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 7 
       [0221]      FIGS. 25 through 28  and Tables 19 through 21 show a seventh numerical embodiment of the zoom lens system according to the present invention.  FIG. 25  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 26 ,  27  and  28  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 19 shows the lens surface data, Table 20 shows various lens-system data, and Table 21 shows the lens group data. 
         [0222]    The lens arrangement of the seventh numerical embodiment differs overall from that of the first through sixth numerical embodiments. 
         [0223]    (1) The zoom lens system is configured of a positive first lens group G 1 ″, a negative second lens group G 2 ″, a positive third lens group G 3 ″, a negative fourth lens group G 4 ″ and a positive fifth lens group G 5 ″, in that order from the object side (five lens groups constituting a positive-negative-positive-negative-positive lens group configuration of a zoom lens system). 
         [0224]    (2) The first lens group G 1 ″ is configured of a negative meniscus lens element  151  having a convex surface on the object side, a biconvex positive lens element  152 , and a positive meniscus lens element  153  having a convex surface on the object side, in that order from the object side. The surface on the image side of the negative meniscus lens element  151  and the surface on the object side of the biconvex positive lens element  152  are cemented to each other, and the diffraction surface DS, which has a rotationally symmetric shape with respect to the optical axis, is formed on the cemented surface thereof. 
         [0225]    (3) The second lens group G 2 ″ is configured of a negative meniscus lens element  221  having a convex surface on the object side, a negative meniscus lens element  222  having a convex surface on the image side, a biconvex positive lens element  223 , and a biconcave negative lens element  224 , in that order from the object side. The surface on the image side of the biconvex positive lens element  223  and the surface on the object side of the biconcave negative lens element  224  are cemented to each other. 
         [0226]    (4) The third lens group G 3 ″ is configured of a biconvex positive lens element  321 , a biconvex positive lens element  322 , and a negative meniscus lens element  323  having a convex surface on the image side, in that order from the object side. The surface on the image side of the biconvex positive lens element  322  and the surface on the object side of the negative meniscus lens element  323  are cemented to each other. 
         [0227]    (5) The fourth lens group G 4 ″ is configured of a positive meniscus lens element  451  having a convex surface on the image side, and a biconcave negative lens element  452 , in that order from the object side. The surface on the image side of the positive meniscus lens element  451  and the surface on the object side of the biconcave negative lens element  452  are cemented to each other. 
         [0228]    (6) The fifth lens group G 5 ″ is configured of a biconvex positive lens element  501 , a negative meniscus lens element  502  having a convex surface on the object side, and a positive meniscus lens element  503  having a convex surface on the object side, in that order from the object side. 
         [0229]    (7) An ND filter ND for light-quantity adjustment and an aperture diaphragm S are provided, in that order from the object side, between the second lens group G 2 ″ and the third lens group G 3 ″ (immediately in front of the third lens group G 3 ″). 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 19 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 158.591 
                 2.000 
                 1.80400 
                 46.6 
                 0.5573 
               
               
                  2 
                 72.113 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  3* 
                 72.113 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  4 
                 72.113 
                 12.460 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  5 
                 −276.991 
                 0.432 
               
               
                  6 
                 65.970 
                 9.906 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  7 
                 843.383 
                 d7 
               
               
                  8 
                 91.741 
                 1.458 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                  9 
                 15.890 
                 4.198 
               
               
                 10 
                 −23.106 
                 1.458 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 11 
                 −283.908 
                 2.000 
               
               
                 12 
                 49.874 
                 5.562 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 13 
                 −38.997 
                 2.000 
                 1.88300 
                 40.8 
                 0.5667 
               
               
                 14 
                 91.709 
                 d14 
               
               
                 15 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 16 
                 ∞ 
                 2.500 
               
               
                 17(Diaphragm) 
                 ∞ 
                 1.296 
               
               
                 18 
                 63.212 
                 4.857 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 19 
                 −33.118 
                 0.119 
               
               
                 20 
                 36.198 
                 6.966 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 21 
                 −23.711 
                 1.458 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 22 
                 −61.573 
                 d22 
               
               
                 23 
                 −53.009 
                 5.821 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 24 
                 −20.981 
                 1.500 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 25 
                 73.636 
                 d25 
               
               
                 26 
                 50.923 
                 2.970 
                 1.56908 
                 71.3 
                 0.5450 
               
               
                 27 
                 −25.444 
                 0.419 
               
               
                 28 
                 32.163 
                 1.782 
                 1.64769 
                 33.8 
                 0.5938 
               
               
                 29 
                 8.910 
                 0.672 
               
               
                 30 
                 12.816 
                 4.050 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 31 
                 25.201 
                 11.200 
               
               
                 32 
                 ∞ 
                 5.616 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 33 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −1.02441E−02 
                 P4 = 3.22386E−06 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 151 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5573 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 20 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 52.50 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 3.2 
                 3.9 
                 6.4 
               
               
                 f 
                 8.00 
                 58.00 
                 420.00 
               
               
                 W 
                 23.3 
                 3.3 
                 0.4 
               
               
                 Y 
                 3.40 
                 3.40 
                 3.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 237.40 
                 237.40 
                 237.40 
               
               
                 d7 
                 2.900 
                 73.521 
                 102.935 
               
               
                 d14 
                 105.920 
                 35.299 
                 5.885 
               
               
                 d22 
                 5.629 
                 20.917 
                 2.960 
               
               
                 d25 
                 28.053 
                 12.766 
                 30.722 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 15.97 
                 3.91 
                 0.28 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 21 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 129.25 
               
               
                 2 
                 8 
                 −14.33 
               
               
                 3 
                 15 
                 30.25 
               
               
                 4 
                 23 
                 −40.01 
               
               
                 5 
                 26 
                 60.31 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 8 
       [0230]      FIGS. 29 through 32  and Tables 22 through 24 show an eighth numerical embodiment of the zoom lens system according to the present invention.  FIG. 29  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 30 ,  31  and  32  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 22 shows the lens surface data, Table 23 shows various lens-system data, and Table 24 shows the lens group data. 
         [0231]    The lens arrangement of the eighth numerical embodiment is the same as that of the seventh numerical embodiment except for the following: 
         [0232]    (1) In the second lens group G 2 ″, the negative lens element  222  is configured of a biconcave negative lens element, the positive lens element  223  is configured of a positive meniscus lens element having convex surface on the object side, and the negative lens element  224  is configured of a negative meniscus lens element having a convex surface on the object side. 
         [0233]    (2) The negative lens element  452  of the fourth lens group G 4 ″ is configured of a negative meniscus lens element having a convex surface on the image side. 
         [0234]    (3) The fifth lens group G 5 ″ is configured of a biconvex positive lens element  511  and a negative meniscus lens element  512  having a convex surface on the object side, in that order from the object side. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 22 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 135.941 
                 2.000 
                 1.80610 
                 40.9 
                 0.5701 
               
               
                  2 
                 63.371 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  3* 
                 63.371 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  4 
                 63.371 
                 12.460 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                  5 
                 −981.982 
                 0.432 
               
               
                  6 
                 61.493 
                 9.906 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                  7 
                 262.222 
                 d7 
               
               
                  8 
                 50.988 
                 1.458 
                 1.80400 
                 46.6 
                 0.5573 
               
               
                  9 
                 12.975 
                 4.198 
               
               
                 10 
                 −37.569 
                 1.458 
                 1.80400 
                 46.6 
                 0.5573 
               
               
                 11 
                 57.046 
                 2.000 
               
               
                 12 
                 23.701 
                 5.562 
                 1.95906 
                 17.5 
                 0.6598 
               
               
                 13 
                 98.949 
                 2.000 
                 1.85026 
                 32.3 
                 0.5929 
               
               
                 14 
                 28.764 
                 d14 
               
               
                 15 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 16 
                 ∞ 
                 2.500 
               
               
                 17(Diaphragm) 
                 ∞ 
                 1.296 
               
               
                 18 
                 46.844 
                 3.442 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 19 
                 −29.933 
                 0.119 
               
               
                 20 
                 48.245 
                 3.488 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 21 
                 −19.939 
                 1.458 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 22 
                 −40.859 
                 d22 
               
               
                 23 
                 −22.246 
                 2.502 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 24 
                 −16.663 
                 1.500 
                 1.80440 
                 39.6 
                 0.5729 
               
               
                 25 
                 −65.957 
                 d25 
               
               
                 26 
                 14.321 
                 2.970 
                 1.56908 
                 71.3 
                 0.5450 
               
               
                 27 
                 −41.609 
                 0.419 
               
               
                 28 
                 9.498 
                 1.782 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 29 
                 5.218 
                 12.595 
               
               
                 30 
                 ∞ 
                 3.500 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 31 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −9.58436E−03 
                 P4 = 4.14533E−07 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 151 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5701 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 23 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 66.41 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 3.2 
                 5.0 
                 7.4 
               
               
                 f 
                 6.40 
                 59.40 
                 425.00 
               
               
                 W 
                 27.2 
                 3.1 
                 0.4 
               
               
                 Y 
                 3.40 
                 3.40 
                 3.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 199.90 
                 219.81 
                 250.62 
               
               
                 d7 
                 2.603 
                 68.662 
                 93.662 
               
               
                 d14 
                 94.393 
                 28.336 
                 3.298 
               
               
                 d22 
                 7.537 
                 20.266 
                 24.892 
               
               
                 d25 
                 14.116 
                 21.298 
                 47.518 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 19.10 
                 4.22 
                 0.94 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 24 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 128.25 
               
               
                 2 
                 8 
                 −12.83 
               
               
                 3 
                 15 
                 26.88 
               
               
                 4 
                 23 
                 −48.09 
               
               
                 5 
                 26 
                 128.00 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 9 
       [0235]      FIGS. 33 through 36  and Tables 25 through 27 show a ninth numerical embodiment of the zoom lens system according to the present invention.  FIG. 33  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 34 ,  35  and  36  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 25 shows the lens surface data, Table 26 shows various lens-system data, and Table 27 shows the lens group data. 
         [0236]    The lens arrangement of the ninth numerical embodiment is the same as that of the fourth numerical embodiment. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 25 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 780.971 
                 3.500 
                 1.83400 
                 37.3 
                 0.5789 
               
               
                  2 
                 161.512 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  3* 
                 161.512 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  4 
                 161.512 
                 16.401 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                  5 
                 −470.007 
                 0.200 
               
               
                  6 
                 148.552 
                 13.241 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                  7 
                 393.615 
                 0.200 
               
               
                  8 
                 133.838 
                 10.144 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                  9 
                 524.900 
                 d9 
               
               
                 10 
                 −185.266 
                 2.406 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 11 
                 105.189 
                 1.244 
               
               
                 12 
                 160.877 
                 6.223 
                 1.95906 
                 17.5 
                 0.6598 
               
               
                 13 
                 −87.492 
                 1.521 
                 1.79952 
                 42.2 
                 0.5672 
               
               
                 14 
                 41.161 
                 d14 
               
               
                 15 
                 −47.635 
                 1.615 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 16 
                 19.338 
                 3.423 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 17 
                 41.155 
                 d17 
               
               
                 18 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 19 
                 ∞ 
                 0.900 
               
               
                 20(Diaphragm) 
                 ∞ 
                 2.200 
               
               
                 21 
                 273.011 
                 5.358 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 22 
                 −63.836 
                 0.100 
               
               
                 23 
                 64.502 
                 7.466 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 24 
                 −47.586 
                 2.424 
                 1.80400 
                 46.6 
                 0.5573 
               
               
                 25 
                 −117.919 
                 0.200 
               
               
                 26 
                 37.547 
                 6.000 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 27 
                 236.611 
                 5.615 
               
               
                 28 
                 79.896 
                 2.424 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 29 
                 33.393 
                 3.818 
               
               
                 30 
                 132.347 
                 2.000 
                 1.72916 
                 54.7 
                 0.5444 
               
               
                 31 
                 41.081 
                 6.500 
                 1.59522 
                 67.7 
                 0.5442 
               
               
                 32 
                 −810.124 
                 85.529 
               
               
                 33 
                 ∞ 
                 3.500 
                 1.51680 
                 64.2 
                 0.5343 
               
               
                 34 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −2.21152E−02 
                 P4 = −4.77057E−08 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 121 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5789 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 26 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 99.61 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 4.0 
                 4.0 
                 12.1 
               
               
                 f 
                 12.80 
                 108.00 
                 1275.00 
               
               
                 W 
                 20.4 
                 2.4 
                 0.2 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 403.18 
                 403.18 
                 403.18 
               
               
                 d9 
                 5.982 
                 120.422 
                 149.326 
               
               
                 d14 
                 137.032 
                 20.669 
                 55.474 
               
               
                 d17 
                 63.810 
                 65.733 
                 2.024 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 12.22 
                 1.29 
                 0.11 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 27 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 197.32 
               
               
                 2 
                 10 
                 −40.33 
               
               
                 3 
                 15 
                 −43.33 
               
               
                 4 
                 18 
                 54.68 
               
               
                   
               
             
          
         
       
     
       Numerical Embodiment 10 
       [0237]      FIGS. 37 through 40  and Tables 28 through 30 show a tenth numerical embodiment of the zoom lens system according to the present invention.  FIG. 37  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 38 ,  39  and  40  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 28 shows the lens surface data, Table 29 shows various lens-system data, and Table 30 shows the lens group data. 
         [0238]    The lens arrangement of the tenth numerical embodiment is the same as that of the third numerical embodiment except for the following: 
         [0239]    (1) The negative lens element  121  of the first lens group G 1  is not a biconcave negative lens element, but rather a negative meniscus lens element having a convex surface on the object side. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 28 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 456.906 
                 3.168 
                 1.80440 
                 39.6 
                 0.5729 
               
               
                  2 
                 144.518 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  3* 
                 144.518 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  4 
                 144.518 
                 14.430 
                 1.48749 
                 70.2 
                 0.5300 
               
               
                  5 
                 −3656.683 
                 0.200 
               
               
                  6 
                 161.860 
                 11.059 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  7 
                 4948.334 
                 0.200 
               
               
                  8 
                 123.760 
                 11.450 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  9 
                 581.971 
                 d9 
               
               
                 10 
                 −149.581 
                 2.000 
                 1.74950 
                 35.3 
                 0.5869 
               
               
                 11 
                 78.458 
                 0.780 
               
               
                 12 
                 130.245 
                 6.000 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 13 
                 −57.620 
                 2.240 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 14 
                 45.962 
                 d14 
               
               
                 15 
                 −45.852 
                 1.000 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 16 
                 18.400 
                 2.804 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 17 
                 39.732 
                 d17 
               
               
                 18(Diaphragm) 
                 ∞ 
                 0.600 
               
               
                 19 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 20 
                 ∞ 
                 2.200 
               
               
                 21 
                 85.714 
                 5.275 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 22 
                 −84.923 
                 0.100 
               
               
                 23 
                 51.387 
                 4.397 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 24 
                 −1122.681 
                 0.100 
               
               
                 25 
                 49.896 
                 6.199 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 26 
                 −49.463 
                 2.588 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 27 
                 49.938 
                 6.185 
               
               
                 28 
                 28.740 
                 5.198 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 29 
                 677.918 
                 0.100 
               
               
                 30 
                 32.577 
                 1.800 
                 1.69680 
                 55.5 
                 0.5434 
               
               
                 31 
                 18.949 
                 82.106 
               
               
                 32 
                 ∞ 
                 3.500 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 33 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −1.95080E−02 
                 P4 = −3.68543E−09 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 121 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5729 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 29 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 62.50 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 4.0 
                 4.0 
                 11.9 
               
               
                 f 
                 20.00 
                 158.00 
                 1250.00 
               
               
                 W 
                 12.8 
                 1.6 
                 0.2 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 389.49 
                 389.49 
                 389.49 
               
               
                 d9 
                 50.617 
                 132.857 
                 147.107 
               
               
                 d14 
                 84.219 
                 7.187 
                 60.038 
               
               
                 d17 
                 76.778 
                 71.570 
                 4.469 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 8.93 
                 1.72 
                 0.12 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 30 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 194.88 
               
               
                 2 
                 10 
                 −40.30 
               
               
                 3 
                 15 
                 −42.14 
               
               
                 4 
                 18 
                 54.66 
               
               
                   
               
             
          
         
       
     
       Reference Example 
       [0240]      FIGS. 41 through 44  and Tables 31 through 33 show a reference example of the zoom lens system according to the above-described first through tenth numerical embodiments of the present invention.  FIG. 41  shows the lens arrangement at the short focal length extremity when focused on an object at infinity.  FIGS. 42 ,  43  and  44  show various aberration diagrams at the short focal length extremity, at an intermediate focal length and at the long focal length extremity, respectively, when focused on an object at infinity. Table 31 shows the lens surface data, Table 32 shows various lens-system data, and Table 33 shows the lens group data. 
         [0241]    The lens arrangement of this reference example includes an extender (rear converter) EX, for changing the focal length of the entire lens system (e.g., doubling the focal length) toward the long focal length side, provided in optical path between the fourth lens group G 4  and the cover glass CG, with respect to the lens arrangement of the tenth numerical embodiment. The extender EX is insertable into the optical path between the fourth lens group G 4  and the cover glass CG. The extender EX is configured of a positive meniscus lens element EX 1  having a convex surface on the object side, a cemented lens configured of a biconvex positive lens element EX 2  and a biconcave negative lens element EX 3 , and a cemented lens configured of a positive meniscus lens element EX 4  having a convex surface on the image side and a biconcave negative lens element EX 5 , in that order from the object side. 
         [0000]    
       
         
               
             
               
               
               
               
               
               
             
               
             
               
               
               
               
             
               
             
               
               
             
           
               
                 TABLE 31 
               
               
                   
               
             
             
               
                 SURFACE DATA 
               
             
          
           
               
                 Surf. No. 
                 R 
                 d 
                 N(d) 
                 ν (d) 
                 θ g F 
               
               
                   
               
               
                  1 
                 456.906 
                 3.168 
                 1.80440 
                 39.6 
                 0.5729 
               
               
                  2 
                 144.518 
                 0.100 
                 1.64310 
                 38.8 
                 0.5799 
               
               
                  3* 
                 144.518 
                 0.100 
                 1.61505 
                 26.5 
                 0.6153 
               
               
                  4 
                 144.518 
                 14.430 
                 1.48749 
                 70.2 
                 0.5300 
               
               
                  5 
                 −3656.683 
                 0.200 
               
               
                  6 
                 161.860 
                 11.059 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  7 
                 4948.334 
                 0.200 
               
               
                  8 
                 123.760 
                 11.450 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                  9 
                 581.971 
                 d9 
               
               
                 10 
                 −149.581 
                 2.000 
                 1.74950 
                 35.3 
                 0.5869 
               
               
                 11 
                 78.458 
                 0.780 
               
               
                 12 
                 130.245 
                 6.000 
                 1.92286 
                 18.9 
                 0.6495 
               
               
                 13 
                 −57.620 
                 2.240 
                 1.83400 
                 37.2 
                 0.5776 
               
               
                 14 
                 45.962 
                 d14 
               
               
                 15 
                 −45.852 
                 1.000 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 16 
                 18.400 
                 2.804 
                 1.80610 
                 33.3 
                 0.5883 
               
               
                 17 
                 39.732 
                 d17 
               
               
                 18(Diaphragm) 
                 ∞ 
                 0.600 
               
               
                 19 
                 ∞ 
                 1.000 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 20 
                 ∞ 
                 2.200 
               
               
                 21 
                 85.714 
                 5.275 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 22 
                 −84.923 
                 0.100 
               
               
                 23 
                 51.387 
                 4.397 
                 1.43875 
                 95.0 
                 0.5340 
               
               
                 24 
                 −1122.681 
                 0.100 
               
               
                 25 
                 49.896 
                 6.199 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 26 
                 −49.463 
                 2.588 
                 1.77250 
                 49.6 
                 0.5520 
               
               
                 27 
                 49.938 
                 6.185 
               
               
                 28 
                 28.740 
                 5.198 
                 1.61800 
                 63.4 
                 0.5441 
               
               
                 29 
                 677.918 
                 0.100 
               
               
                 30 
                 32.577 
                 1.800 
                 1.69680 
                 55.5 
                 0.5434 
               
               
                 31 
                 18.949 
                 d31 
               
               
                 32 
                 25.539 
                 3.744 
                 1.49700 
                 81.6 
                 0.5375 
               
               
                 33 
                 414.942 
                 6.094 
               
               
                 34 
                 68.444 
                 2.818 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 35 
                 −38.918 
                 1.200 
                 1.60342 
                 38.0 
                 0.5835 
               
               
                 36 
                 37.893 
                 10.426 
               
               
                 37 
                 −96.642 
                 2.486 
                 1.80518 
                 25.4 
                 0.6161 
               
               
                 38 
                 −13.489 
                 1.696 
                 1.72916 
                 54.7 
                 0.5444 
               
               
                 39 
                 13.047 
                 45.277 
               
               
                 40 
                 ∞ 
                 3.500 
                 1.51633 
                 64.1 
                 0.5353 
               
               
                 41 
                 ∞ 
                 — 
               
               
                   
               
             
          
           
               
                 Optical Path Difference Function Coefficients for Diffraction 
               
               
                 Surface DS 
               
               
                   
               
             
          
           
               
                   
                 NO. 3 
                 P2 = −1.95080E−02 
                 P4 = −3.68543E−09 
               
               
                   
                   
               
             
          
           
               
                 Partial Dispersion Ratio for Negative Lens Element 121 
               
               
                   
               
             
          
           
               
                   
                 θ gF = 0.5729 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
               
             
               
               
               
               
             
           
               
                 TABLE 32 
               
             
             
               
                   
               
               
                 VARIOUS LENS SYSTEM DATA 
               
               
                 Zoom Ratio: 62.50 
               
             
          
           
               
                   
                 Short Focal Length 
                 Intermediate 
                 Long Focal Length 
               
               
                   
                 Extremity 
                 Focal Length 
                 Extremity 
               
               
                   
                   
               
             
          
           
               
                 FNO. 
                 8.0 
                 8.0 
                 23.8 
               
               
                 f 
                 40.00 
                 316.04 
                 2500.28 
               
               
                 W 
                 6.3 
                 0.8 
                 0.1 
               
               
                 Y 
                 4.40 
                 4.40 
                 4.40 
               
               
                 fB 
                 1.00 
                 1.00 
                 1.00 
               
               
                 L 
                 389.49 
                 389.49 
                 389.49 
               
               
                 d9 
                 50.617 
                 132.857 
                 147.107 
               
               
                 d14 
                 84.219 
                 7.187 
                 60.038 
               
               
                 d17 
                 76.778 
                 71.570 
                 4.469 
               
               
                 d31 
                 8.365 
                 8.365 
                 8.365 
               
             
          
           
               
                 Diffraction Surface Incidence Angle (°) 
               
             
          
           
               
                   
                 4.37 
                 0.89 
                 0.06 
               
               
                   
                   
               
             
          
         
       
     
         [0000]    
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 33 
               
             
             
               
                   
               
               
                 LENS GROUP DATA 
               
             
          
           
               
                 Lens Group 
                 1 st  Surf. 
                 Focal Length 
               
               
                   
               
             
          
           
               
                 1 
                 1 
                 194.88 
               
               
                 2 
                 11 
                 −40.30 
               
               
                 3 
                 16 
                 −42.14 
               
               
                 4 
                 20 
                 54.66 
               
               
                 5 
                 32 
                 −36.03 
               
               
                   
               
             
          
         
       
     
         [0242]    The numerical values of each condition for each embodiment are shown in Table 34. In conditions (3), (4), (5), (7), (10), (13) and (14), the numbers in parentheses next to the values corresponding to these conditions indicate the lens numbers of the lens elements that satisfy the respective conditions. In the sixth through eighth numerical embodiments, since the lens arrangement required for condition (11) is different (the third lens group G 3  has a positive refractive power), numerical values corresponding to condition (11) cannot be calculated. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
             
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
             
               
               
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 34 
               
               
                   
               
             
             
               
                   
                 Embod. 1 
                 Embod. 2 
                 Embod. 3 
                 Embod. 4 
               
               
                   
               
               
                 Cond. (1) 
                 9765.5 
                 9365.1 
                 2188.6 
                 138.6 
               
               
                 Cond. (2) 
                 0.300 
                 0.231 
                 0.231 
                 0.155 
               
             
          
           
               
                 Cond. (3) 
                 44.2 
                 (101) 
                 51.5 
                 (111) 
                 55.4 
                 (121) 
                 33.3 
                 (121) 
               
               
                   
                   
                   
                 91.4 
                 (113) 
               
               
                 Cond. (4) 
                 0.5631 
                 (101) 
                 0.5486 
                 (111) 
                 0.5484 
                 (121) 
                 0.5883 
                 (121) 
               
               
                   
                   
                   
                 0.5342 
                 (113) 
               
               
                 Cond. (5) 
                 95.0 
                 (102) 
                 81.6 
                 (112) 
                 95.0 
                 (122) 
                 71.3 
                 (122) 
               
               
                   
                 95.0 
                 (103) 
                 95.0 
                 (114) 
                 95.0 
                 (123) 
               
               
                   
                   
                   
                 95.0 
                 (115) 
                 95.0 
                 (124) 
               
             
          
           
               
                 Cond. (6) 
                 6.45 
                 2.93 
                 3.97 
                 4.50 
               
             
          
           
               
                 Cond. (7) 
                 22.8 
                 (202) 
                 18.9 
                 (202) 
                 18.9 
                 (202) 
                 17.5 
                 (202) 
               
             
          
           
               
                 Cond. (8) 
                 −0.67 
                 −0.75 
                 −0.75 
                 −0.32 
               
               
                 Cond. (9) 
                 0.97 
                 0.86 
                 0.86 
                 1.18 
               
             
          
           
               
                 Cond. (10) 
                 81.6 
                 (401) 
                 95.0 
                 (411) 
                 95.0 
                 (411) 
                 81.6 
                 (421) 
               
               
                   
                   
                   
                 95.0 
                 (412) 
                 95.0 
                 (412) 
                 95.0 
                 (422) 
               
               
                   
                   
                   
                 81.6 
                 (413) 
                 81.6 
                 (413) 
                 95.0 
                 (424) 
               
             
          
           
               
                 Cond. (11) 
                 1.75 
                 2.44 
                 2.44 
                 0.93 
               
               
                 Cond. (12) 
                 4944.9 
                 4532.8 
                 1346.6 
                 147.2 
               
             
          
           
               
                 Cond. (13) 
                 0.0115 
                 (102) 
                 0.0083 
                 (112) 
                 0.0115 
                 (122) 
                 0.0107 
                 (122) 
               
               
                   
                 0.0115 
                 (103) 
                 0.0115 
                 (114) 
                 0.0115 
                 (123) 
               
               
                   
                   
                   
                 0.0115 
                 (115) 
                 0.0115 
                 (124) 
               
               
                 Cond. (14) 
                 0.0030 
                 (202) 
                 0.0214 
                 (202) 
                 0.0214 
                 (202) 
                 0.0316 
                 (202) 
               
             
          
           
               
                 Cond. (15) 
                 1482.2 
                 1047.8 
                 311.3 
                 22.8 
               
               
                 Cond. (16) 
                 −0.77 
                 0.86 
                 0.86 
                 0.28 
               
               
                   
               
               
                   
                 Embod. 5 
                 Embod. 6 
                 Embod. 7 
                 Embod. 8 
               
               
                   
               
               
                 Cond. (1) 
                 143.7 
                 138.9 
                 1151.9 
                 1401.1 
               
               
                 Cond. (2) 
                 0.153 
                 0.208 
                 0.308 
                 0.302 
               
             
          
           
               
                 Cond. (3) 
                 39.6 
                 (135) 
                 91.4 
                 (144) 
                 46.6 
                 (151) 
                 40.9 
                 (151) 
               
               
                 Cond. (4) 
                 0.5729 
                 (135) 
                 0.5342 
                 (144) 
                 0.5573 
                 (151) 
                 0.5701 
                 (151) 
               
               
                 Cond. (5) 
                 95.0 
                 (133) 
                 95.0 
                 (143) 
                 95.0 
                 (152) 
                 81.6 
                 (152) 
               
               
                   
                 95.0 
                 (134) 
                   
                   
                 95.0 
                 (153) 
                 81.6 
                 (153) 
               
             
          
           
               
                 Cond. (6) 
                 3.12 
                 2.98 
                 5.17 
                 5.13 
               
             
          
           
               
                 Cond. (7) 
                 18.9 
                 (202) 
                 22.8 
                 (214) 
                 18.9 
                 (223) 
                 17.5 
                 (223) 
               
             
          
           
               
                 Cond. (8) 
                 −0.23 
                 −0.24 
                 −0.25 
                 −0.25 
               
               
                 Cond. (9) 
                 1.12 
                 1.15 
                 0.56 
                 0.65 
               
             
          
           
               
                 Cond. (10) 
                 81.6 
                 (431) 
                 95.0 
                 (442) 
                 71.3 
                 (501) 
                 71.3 
                 (511) 
               
               
                   
                 81.6 
                 (432) 
                 81.6 
                 (444) 
               
               
                   
                 95.0 
                 (433) 
               
               
                   
                 95.0 
                 (435) 
               
             
          
           
               
                 Cond. (11) 
                 0.95 
                 — 
                 — 
                 — 
               
               
                 Cond. (12) 
                 183.9 
                 148.5 
                 642.7 
                 692.3 
               
             
          
           
               
                 Cond. (13) 
                 0.0115 
                 (133) 
                 0.0334 
                 (142) 
                 0.0115 
                 (152) 
                 0.0083 
                 (152) 
               
               
                   
                 0.0115 
                 (134) 
                 0.0115 
                 (143) 
                 0.0115 
                 (153) 
                 0.0083 
                 (153) 
               
               
                 Cond. (14) 
                 0.0214 
                 (202) 
                 0.0030 
                 (214) 
                 0.0214 
                 (223) 
                 0.0316 
                 (223) 
               
             
          
           
               
                 Cond. (15) 
                 28.1 
                 30.9 
                 197.8 
                 208.9 
               
               
                 Cond. (16) 
                 0.08 
                 1.74 
                 1.42 
                 1.68 
               
               
                   
               
             
          
           
               
                   
                   
                 Embod. 9 
                 Embod. 10 
               
               
                   
                   
               
               
                   
                 Cond. (1) 
                 238.2 
                 301.8 
               
               
                   
                 Cond. (2) 
                 0.155 
                 0.156 
               
             
          
           
               
                   
                 Cond. (3) 
                 37.3 
                 (121) 
                 39.6 
                 (121) 
               
               
                   
                 Cond. (4) 
                 0.5789 
                 (121) 
                 0.5729 
                 (121) 
               
               
                   
                 Cond. (5) 
                 81.6 
                 (122) 
                 95.0 
                 (123) 
               
               
                   
                   
                 81.6 
                 (123) 
                 95.0 
                 (124) 
               
             
          
           
               
                   
                 Cond. (6) 
                 4.50 
                 4.79 
               
             
          
           
               
                   
                 Cond. (7) 
                 17.5 
                 (202) 
                 18.9 
                 (202) 
               
             
          
           
               
                   
                 Cond. (8) 
                 −0.32 
                 −0.25 
               
               
                   
                 Cond. (9) 
                 1.18 
                 0.99 
               
             
          
           
               
                   
                 Cond. (10) 
                 81.6 
                 (421) 
                 95.0 
                 (411) 
               
               
                   
                   
                 95.0 
                 (422) 
                 95.0 
                 (412) 
               
               
                   
                   
                 95.0 
                 (424) 
                 81.6 
                 (413) 
               
             
          
           
               
                   
                 Cond. (11) 
                 0.93 
                 0.96 
               
               
                   
                 Cond. (12) 
                 195.0 
                 223.8 
               
             
          
           
               
                   
                 Cond. (13) 
                 0.0083 
                 (122) 
                 0.0115 
                 (123) 
               
               
                   
                   
                 0.0083 
                 (123) 
                 0.0115 
                 (124) 
               
               
                   
                 Cond. (14) 
                 0.0316 
                 (202) 
                 0.0214 
                 (202) 
               
             
          
           
               
                   
                 Cond. (15) 
                 30.2 
                 34.9 
               
               
                   
                 Cond. (16) 
                 0.28 
                 0.31 
               
               
                   
                   
               
             
          
         
       
     
         [0243]    As can be understood from Table 34, the first through fifth, ninth and tenth numerical embodiments satisfy conditions (1) through (14), and the sixth through eighth numerical embodiments satisfy conditions (1) through (10) and conditions (12) through (14). As can be understood from the various aberration diagrams, the various aberrations are relatively well corrected. 
         [0244]    The technical scope of the present invention would not be evaded even if a lens element or lens group which has, in effect, no optical power were to be added to a zoom lens system that is included in the technical scope of the present invention. 
       INDUSTRIAL APPLICABILITY 
       [0245]    The zoom lens system of the present invention are suitable for use in, for example, a day-and-night surveillance lens system (day-and-night lens). 
       REFERENCE SIGNS LIST 
       [0000]    
       
         G 1  Positive first lens group 
         G 2  Negative second lens group 
         G 3  Negative third lens group 
         G 4  Positive fourth lens group (stationary lens group) 
         G 1 ′ Positive first lens group 
         G 2 ′ Negative second lens group 
         G 3 ′ Positive third lens group 
         G 4 ′ Negative fourth lens group (stationary lens group) 
         G 1 ″ Positive first lens group 
         G 2 ″ Negative second lens group 
         G 3 ″ Positive third lens group 
         G 4 ″ Negative fourth lens group 
         G 5 ″ Positive fifth lens group (stationary lens group) 
           101 ,  102  Cemented lens having diffraction surface 
           113 ,  114  Cemented lens having diffraction surface 
           121 ,  122  Cemented lens having diffraction surface 
           131 ,  132  Cemented lens having diffraction surface 
           143 ,  144  Cemented lens having diffraction surface 
           151 ,  152  Cemented lens having diffraction surface 
         DS Diffraction surface (diffraction lens surface) 
         ND ND Filter 
         S Diaphragm 
         I Imaging surface