Patent Publication Number: US-2021165196-A1

Title: Zoom lens and image capturing apparatus including the same

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The aspect of the embodiments relates to a zoom lens suitable for image capturing apparatus, such as a digital video camera, a digital still camera, a camera for broadcast, a camera for silver-halide film, and a monitoring camera. 
     Description of the Related Art 
     As a zoom lens that is used for an image capturing apparatus, a negative-lead zoom lens in which a lens unit having negative refractive power is disposed at a position closest to the object has been known. 
     Japanese Patent Laid-Open No. 2014-178388 discusses a negative-lead zoom lens including a first lens unit having negative refractive power, a second lens unit having positive refractive power, and a subsequent lens unit. 
     To enhance optical performance while weight reduction of a zoom lens is achieved, it is important to appropriately specify the number of lens units included in the zoom lens and the refractive power in agreement with each other. 
     In the zoom lens discussed in Japanese Patent Laid-Open No. 2014-178388, enhanced performance and weight reduction of the zoom lens are balanced insufficiently. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the embodiments, there is provided a zoom lens including a first lens unit having negative refractive power, a second lens unit having positive refractive power, and a third lens unit having negative refractive power in order from an object side to an image side, wherein a distance between the first lens unit and the second lens unit and a distance between the second lens unit and the third lens unit change during at least one of zooming and focusing, wherein the first lens unit moves during zooming, wherein the first lens unit includes a negative lens G 1  disposed closest to the object side and at least one positive lens, wherein lenses included in the second lens unit all have positive refractive power, wherein a number of lenses included in the third lens unit is two or less, wherein the third lens unit moves toward the image side during focusing from infinity to close range, and wherein the following inequality is satisfied: 
       1.40&lt; Nd _ G 1&lt;1.80 
     where Nd_G 1  is a refractive index of the negative lens G 1 . 
     Further features of the disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  are cross-sectional views of a zoom lens according to a first exemplary embodiment. 
         FIGS. 2A and 2B  are aberration diagrams of the zoom lens according to the first exemplary embodiment. 
         FIGS. 3A and 3B  are cross-sectional views of a zoom lens according to a second exemplary embodiment. 
         FIGS. 4A and 4B  are aberration diagrams of the zoom lens according to the second exemplary embodiment. 
         FIGS. 5A and 5B  are cross-sectional views of a zoom lens according to a third exemplary embodiment. 
         FIGS. 6A and 6B  are aberration diagrams of the zoom lens according to the third exemplary embodiment. 
         FIGS. 7A and 7B  are cross-sectional views of a zoom lens according to a fourth exemplary embodiment. 
         FIGS. 8A and 8B  are aberration diagrams of the zoom lens according to the fourth exemplary embodiment. 
         FIGS. 9A and 9B  are cross-sectional views of a zoom lens according to a fifth exemplary embodiment. 
         FIGS. 10A and 10B  are aberration diagrams of the zoom lens according to the fifth exemplary embodiment. 
         FIGS. 11A and 11B  are cross-sectional views of a zoom lens according to a sixth exemplary embodiment. 
         FIGS. 12A and 12B  are aberration diagrams of the zoom lens according to the sixth exemplary embodiment. 
         FIGS. 13A and 13B  are cross-sectional views of a zoom lens according to a seventh exemplary embodiment. 
         FIGS. 14A and 14B  are aberration diagrams of the zoom lens according to the seventh exemplary embodiment. 
         FIGS. 15A and 15B  are cross-sectional views of a zoom lens according to an eighth exemplary embodiment. 
         FIGS. 16A and 16B  are aberration diagrams of the zoom lens according to the eighth exemplary embodiment. 
         FIG. 17  is a schematic diagram illustrating an image capturing apparatus. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     A zoom lens and an image capturing apparatus including the same according to exemplary embodiments of the disclosure will be described below with reference to the attached drawings. 
       FIGS. 1A and 1B ,  FIGS. 3A and 3B ,  FIGS. 5A and 5B ,  FIGS. 7A and 7B ,  FIGS. 9A and 9B ,  FIGS. 11A and 11B ,  FIGS. 13A and 13B , and  FIGS. 15A and 15B  are cross-sectional views of zoom lenses B 0  of first, second, third, fourth, fifth, sixth, seventh, and eighth exemplary embodiments according to the disclosure, respectively.  FIG. 1A ,  FIG. 3A ,  FIG. 5A ,  FIG. 7A ,  FIG. 9A ,  FIG. 11A ,  FIG. 13A , and  FIG. 15A  are cross-sectional views at a wide angle end, and  FIG. 1B ,  FIG. 3B ,  FIG. 5B ,  FIG. 7B ,  FIG. 9B ,  FIG. 11B ,  FIG. 13B , and  FIG. 15B  are cross-sectional views at a telephoto end. 
     The zoom lens B 0  according to each of the exemplary embodiments is used for image capturing apparatuses, such as a digital still camera, a video camera, a silver-halide film camera, a camera for broadcast, and a projection apparatus, such as a projector. In each of the lens cross-sectional views, the left side is the object side (the enlargement side) and the right side is the image side (the reduction side). 
     In each of the lens cross-sectional views, “Bi” (“i” is a natural number) represents the “ith lens unit” where lens units included in the zoom lens B 0  are counted in order from the object side to the image side. The lens unit in the present disclosure is a component of the zoom lens B 0  and includes one or a plurality of lenses. The lenses in each of the lens units integrally move or remain in place during at least one of zooming and focusing, and the distance between the lens units adjacent to each other changes during at least one of zooming and focusing. In a case where optical members (such as a prism, a cover glass, and a filter) having substantially no refractive power are disposed at a position closest to the image or at a position closest to the object in the zoom lens B 0 , the optical members are not described as a part of the zoom lens. 
     An aperture stop SP determines (limits) the amount of light at a full aperture of F-number (Fno). An imaging plane IP is an image place where an image sensor (a photoelectric conversion element), such as a charge coupled device (CCD) sensor and a complementary metal oxide semiconductor (CMOS) sensor, is disposed in a case where the zoom lens B 0  according to each of the exemplary embodiments is used as an image-capturing optical system of a video camera or a digital still camera. In a case where the zoom lens B 0  according to each of the exemplary embodiments is used as an image-capturing optical system of a silver-halide camera, the photosensitive surface of a film is disposed at the imaging plane IP. 
     Arrows illustrated in each of the lens cross-sectional views each represent a simplified movement locus of each of the lens units in zooming from the wide angle end to the telephoto end. Each of the wide angle end and the telephoto end in the present disclosure refers to a zoom position of a state where each of the lens units is at an end of a corresponding mechanically movable range. 
     The zoom lens B 0  according to each of the exemplary embodiments includes a first lens unit B 1  having negative refractive power, a second lens unit B 2  having positive refractive power, and a third lens unit B 3  having negative refractive power, in order from the object side to the image side. Effects of the disclosure can also be effectively achieved even in a case where the zoom lens B 0  further includes another lens unit on the image side of the third lens unit B 3 . 
     In the zoom lens B 0  according to each of the exemplary embodiments, the first lens unit B 1  moves during zooming. The first lens unit B 1  includes a negative lens G 1  at a position closest to the object and at least one positive lens. 
     In the zoom lens B 0  according to each of the exemplary embodiments, lenses included in the second lens unit B 2  all have positive refractive power. In other words, the second lens unit B 2  consists only one or more positive lenses. 
     In the zoom lens B 0  according to each of the exemplary embodiments, the number of lenses included in the third lens unit B 3  is two or less, and the third lens unit B 3  moves toward the image side during focusing from infinity to close range. 
     The zoom lens B 0  according to each of the exemplary embodiments may have a function as an anti-vibration optical system by decentering one or a plurality of lenses in a direction including a component perpendicular to an optical axis in image blurring correction. Further, a parallel plate substantially having no refractive power, for example, a low-pass filter and an infrared cut filter, may be disposed between the lens disposed closest to the object side and the imaging plane IP. 
       FIGS. 2A and 2B ,  FIGS. 4A and 4B ,  FIGS. 6A and 6B ,  FIGS. 8A and 8B ,  FIGS. 10A and 10B ,  FIGS. 12A and 12B ,  FIGS. 14A and 14B , and  FIGS. 16A and 16B  are aberration diagrams each illustrating the zoom lens B 0 , and correspond to the first, second, third, fourth, fifth, sixth, seventh, and eighth exemplary embodiments, respectively.  FIG. 2A ,  FIG. 4A ,  FIG. 6A ,  FIG. 8A ,  FIG. 10A ,  FIG. 12A ,  FIG. 14A , and  FIG. 16A  each illustrate aberration in an infinity in-focus state at the wide angle end, whereas  FIG. 2B ,  FIG. 4B ,  FIG. 6B ,  FIG. 8B ,  FIG. 10B ,  FIG. 12B ,  FIG. 14B , and  FIG. 16B  each illustrate aberration in an infinity in-focus state at the telephoto end. 
     In each of the aberration diagrams, “Fno” indicates an F-number, and “ω” indicates a half angle of view (degree) that is an angle of view determined by paraxial calculation. A spherical aberration diagram illustrates a d-line (a wavelength of 587.6 nm) and a g-line (a wavelength of 435.8 nm). 
     A line S and a dotted line M in an astigmatism diagram represent the d-line at a sagittal image plane and the d-line at a meridional image plane, respectively. A distortion diagram illustrates the d-line. A chromatic aberration diagram illustrates a magnification chromatic aberration amount of the g-line with respect to the d-line. 
     A descriptions will be given of characteristics of the zoom lens B 0  according to each of the exemplary embodiments. 
     The zoom lens B 0  according to each of the exemplary embodiments is a negative-lead zoom lens. The third lens unit B 3  which has negative refractive power and of which diameter is easily reducible is configured to move during focusing, and therefore it is possible to achieve weight reduction of not only a focus lens unit, but also a holding mechanism for holding the focus lens unit as well as a drive mechanism for driving the focus lens unit. The third lens unit B 3  includes two lenses or less, and therefore the weight is further reduced. 
     In the zoom lens B 0  according to each of the exemplary embodiments, the first lens unit B 1  includes the negative lens G 1  at a position closest to the object. This is because, in a negative-lead zoom lens, the diameter of a lens closest to the object can be reduced by using a negative lens as the lens closest to the object. The first lens unit B 1  further includes at least one positive lens. The chromatic aberration of the first lens unit B 1  is thereby successfully corrected. In particular, because the first lens unit B 1  is the lens unit that moves during zooming, variations in magnification chromatic aberration and axial chromatic aberration that occur during zooming can be reduced by the above-describe configuration. 
     In the zoom lens B 0  according to each of the exemplary embodiments, the second lens unit B 2  consists only one or more positive lenses. The second lens unit B 2  functions as a main magnifying unit in the zoom lens B 0  according to each of the exemplary embodiments, and thus it is desirable to provide strong positive refractive power to the second lens unit B 2 . If a negative lens is added to the second lens unit B 2 , the refractive power of the positive lens in the second lens unit B 2  is required to be increased as much as the negative refractive power of the added negative lens. This increases the thickness of the second lens unit B 2 , and consequently weight reduction of the zoom lens B 0  is difficult to achieve. 
     The zoom lens B 0  according to each of the exemplary embodiments satisfies the following inequality (1): 
       1.40&lt; Nd _ G 1&lt;1.80  (1)
 
     where, Nd_G 1  is a refractive index in the d-line of the negative lens G 1 . 
     The inequality (1) defines the refractive index of the negative lens G 1 . In a case where the refractive index exceeds the upper limit of the inequality (1), it is difficult to obtain a material having low specific gravity, i.e., a material beneficial to weight reduction of the zoom lens B 0 . Meanwhile, in a case where the refractive index falls below the lower limit of the inequality (1), the volume of the negative lens G 1  increases when sufficient refractive power is provided to the negative lens G 1 , and consequently the weight reduction is difficult to achieve, which may not desirable. In addition, in the above-described case, the curvature radius of the negative lens G 1  on the image plane side is too small, and consequently it is difficult to successfully reduce or suppress occurrence of the field curvature and the astigmatism at the wide angle end in particular. 
     By satisfying the above-described configuration, the optical system in each of the exemplary embodiments achieves excellent optical performance while being light in weight. 
     As for the numerical range of the above-described inequality (1), it is more desirable to satisfy the following inequality (1a): 
       1.43&lt; Nd _ G 1&lt;1.79  (1a).
 
     It is still more desirable for the numerical range of the above-described inequality (1) to satisfy the following inequality (1b): 
       1.45&lt; Nd _ G 1&lt;1.78  (1b).
 
     Next, a description will be given of a desirable condition which is satisfied in the zoom lens B 0  according to each of the exemplary embodiments. 
     It is desirable for the zoom lens B 0  according to each of the exemplary embodiments to satisfy one or more of the following inequalities (2) to (6): 
       5.0&lt;SF_ B 3 n&lt; 0.50  (2),
 
       1.0&lt;| f 1|/ fw&lt; 3.0  (3),
 
       0.2&lt; f 2/ fw&lt; 5.0  (4),
 
       0.1&lt; f 3/ f 1&lt;5.0  (5), and
 
       18&lt;ν d _ B 3 n&lt; 36  (6).
 
     SF_B 3   n  is a shape factor SF of the negative lens having the strongest refractive power among the negative lenses included in the third lens unit B 3  (in a case where the third lens unit B 3  consists of one negative lens, the shape factor SF is for the one negative lens). The shape factor SF is an amount defined as: 
       SF=( R 2+ R 1)/( R 2− R 1),
 
     where R 1  is the curvature radius of the lens surface on the image side, and R 2  is the curvature radius of the lens surface on the object side. 
     Further, fw is a focal length of the zoom lens B 0  at the wide angle end, f 1  is a focal length of the first lens unit B 1 , f 2  is a focal length of the second lens unit B 2 , f 3  is a focal length of the third lens unit B 3 , and νd_B 3   n  is an Abbe number in the d-line of the negative lens having the strongest refractive power among the negative lenses included in the third lens unit B 3  (in a case where the third lens unit B 3  consists of one negative lens, the Abbe number is for the one negative lens). 
     The inequality (2) defines the shape of the negative lens having the strongest refractive power among the negative lenses included in the third lens unit B 3 . In a case where the value falls below the lower limit of the inequality (2), it is difficult to successfully reduce or suppress a variation in the field curvature that occurs in focusing at the wide angle end, which may not desirable. In a case where the value exceeds the upper limit of the inequality (2), it is difficult to successfully reduce or suppress a variation in the spherical aberration that occurs in focusing at the telephoto end, which may not desirable. 
     The inequality (3) defines the ratio between the focal length of the first lens unit B 1  and the entire system focal length at the wide angle end. In a case where the value falls below the lower limit of the inequality (3), the refractive power of the first lens unit B 1  is too strong, and consequently it is difficult to successfully reduce or suppress the field curvature and the astigmatic difference occurring at the wide angle end. In a case where the value exceeds the upper limit of the inequality (3), the refractive power of the first lens unit B 1  is too weak, and consequently the front diameter (the diameter of the lens closest to the object) is too large. As a result, it is difficult to sufficiently reduce the weight of the zoom lens B 0 . 
     The inequality (4) defines the ratio between the focal length of the second lens unit B 2  and the entire system focal length at the wide angle end. In a case where the value falls below the lower limit of the inequality (4), the refractive power of the second lens unit B 2  is too strong, and consequently it is difficult to successfully reduce or suppress variations in the spherical aberration and the comatic aberration occurring from the wide angle end to the telephoto end. In a case where the value exceeds the upper limit of the inequality (4), the refractive power of the second lens unit B 2  is too weak, and consequently a movement amount of the second lens unit that is required for a desirable zoom ratio is too large. As a result, it is difficult to sufficiently reduce the weight of the zoom lens B 0 . 
     The inequality (5) defines the ratio between the focal length of the third lens unit B 3  and the focal length of the first lens unit B 1 . In a case where the value exceeds the upper limit of the inequality (5), the refractive power of the third lens unit B 3  is too weak, and consequently the movement amount during focusing increases. The increase in the movement amount enlarges the drive mechanism, and consequently it is difficult to sufficiently reduce the weight. In a case where the value falls below the lower limit of the inequality (5), the refractive power of the third lens unit B 3  is too strong, and consequently it is difficult to reduce a change in the optical performance during focusing to a sufficiently small amount. 
     The inequality (6) defines the Abbe number of the negative lens having the strongest refractive power among the negative lenses included in the third lens unit B 3 . In a case where the Abbe number is large to the extent that the Abbe number exceeds the upper limit of the inequality (6), the correction of the chromatic aberration in the entire zoom lens B 0  is insufficient, and consequently high optical performance is insufficiently achieved. In a case where the Abbe number is small to the extent that the Abbe number falls below the lower limit of the inequality (6), the correction of the chromatic aberration in the entire zoom lens B 0  is excessive, and consequently high optical performance is insufficiently achieved. 
     It is more desirable for the numerical ranges of the above-described inequalities (2) to (6) to satisfy the ranges represented by the following inequalities (2a) to (6a), respectively: 
       −4.5&lt;SF_ B 3 n&lt; 0.30  (2a),
 
       1.25&lt;| f 1|/ fw&lt; 2.6  (3a),
 
       0.4&lt; f 2/ fw&lt; 3.0  (4a),
 
       0.2&lt; f 3/ f 1&lt;3.5  (5a), and
 
       19&lt;ν d _ B 3 n&lt; 34  (6a).
 
     It is still more desirable for the numerical ranges of the above-described inequalities (2) to (6) to satisfy the ranges represented by the following inequalities (2b) to (6b), respectively: 
       −4.0&lt;SF_ B 3 n&lt; 0.10  (2b),
 
       1.5&lt;| f 1|/ fw&lt; 2.2  (3b),
 
       0.5&lt; f 2/ fw&lt; 2.0  (4b),
 
       0.3&lt; f 3/ f 1&lt;2.0  (5b), and
 
       20&lt;ν d _ B 3 n&lt; 32  (6b).
 
     Next, a description will be given of a desirable configuration which is satisfied in the zoom lens B 0 . 
     It is desirable for the zoom lens B 0  to be configured in such a manner that the number of the included lenses from the lens closest to the object in the second lens unit B 2  to the lens closest to the image in the zoom lens B 0  be five or less. This number of lenses includes the lens closest to the object in the second lens unit B 2  and the lens closest to the image in the zoom lens B 0 . With this configuration, the weight reduction is easily achieved while the zoom lens B 0  has desirable optical performance. 
     It is further desirable that the number of lenses included in the second lens unit B 2  be two or less. This also facilitates weight reduction while the zoom lens B 0  has desirable optical performance. 
     It is still further desirable that the third lens unit B 3  to consist of a single lens having negative refractive power. This also facilitates weight reduction while the zoom lens B 0  has desirable optical performance. 
     In addition, it is desirable for the first lens unit B 1  to include a lens having an aspherical surface (an aspherical lens). Having the aspherical lens reduces or suppresses the field curvature and the astigmatic difference occurring at the wide angle end. Further, it is desirable that the aspherical lens included in the first lens unit B 1  be a lens made of resin (a resin lens) because this facilitates the weight reduction. 
     Moreover, in the zoom lens B 0  according to each of the exemplary embodiments, it is desirable to correct camera shake by displacing a part or the whole of the second lens unit B 2  in a direction substantially perpendicular to the optical axis. 
     While, in the zoom lens B 0  according to each of the first to eighth exemplary embodiments, the focus lens unit is one lens unit, a plurality of lens units may be used as a focus unit. Such a focusing system is called floating. 
     Not only a refractive optical element (a lens) but also a diffractive optical element may also be used. Further, an optical path may be bent using a reflection optical member. 
     Next, a description in detail will be given of the zoom lens B 0  according to each of the exemplary embodiments. 
     First Exemplary Embodiment 
     As illustrated in  FIGS. 1A and 1B , the zoom lens B 0  according to the first exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, the third lens unit B 3  having negative refractive power, and a fourth lens unit B 4  having positive refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, and the second lens unit B 2  to the fourth lens unit B 4  move toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases, the distance between the second lens unit B 2  and the third lens unit B 3  increases, and the distance between the third lens unit B 3  and the fourth lens unit B 4  decreases. The second lens unit B 2  and the fourth lens unit B 4  move in the identical loci during zooming. 
     The third lens unit B 3  is the focus lens unit, and moves from the object side toward the image side during focusing from an infinity object to a close object. Image blurring (an image position) is corrected by moving the part of the second lens unit B 2  (the fourth lens, a sub-unit B 2 A) on the object side in a direction including a component substantially perpendicular to the optical axis. 
     Second Exemplary Embodiment 
     As illustrated in  FIGS. 3A and 3B , the zoom lens B 0  according to the second exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, the third lens unit B 3  having negative refractive power, and the fourth lens unit B 4  having positive refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, and the second lens unit B 2  to the fourth lens unit B 4  move toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases, the distance between the second lens unit B 2  and the third lens unit B 3  increases, and the distance between the third lens unit B 3  and the fourth lens unit B 4  decreases. The second lens unit B 2  and the fourth lens unit B 4  move in the identical loci during zooming. 
     The third lens unit B 3  is the focus lens unit, and moves from the object side toward the image side during focusing from the infinity object to the close object. Image blurring (the image position) is corrected by moving the part of the second lens unit B 2  (the fourth lens, the sub-unit B 2 A) on the object side in a direction including a component substantially perpendicular to the optical axis. 
     Third Exemplary Embodiment 
     As illustrated in  FIGS. 5A and 5B , the zoom lens B 0  according to the third exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, the third lens unit B 3  having negative refractive power, and the fourth lens unit B 4  having positive refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, and the second lens unit B 2 , the third lens unit B 3 , and the fourth lens unit B 4  move in the identical loci toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases. 
     The third lens unit B 3  is the focus lens unit, and moves from the object side toward the image side during focusing from the infinity object to the close object. Image blurring (the image position) is corrected by moving the part of the second lens unit B 2  (the fourth lens, the sub-unit B 2 A) on the object side in a direction including a component substantially perpendicular to the optical axis. 
     Fourth Exemplary Embodiment 
     As illustrated in  FIGS. 7A and 7B , the zoom lens B 0  according to the fourth exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, the third lens unit B 3  having negative refractive power, and the fourth lens unit B 4  having positive refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, and the second lens unit B 2  to the fourth lens unit B 4  move toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases, the distance between the second lens unit B 2  and the third lens unit B 3  increases, and the distance between the third lens unit B 3  and the fourth lens unit B 4  decreases. The second lens unit B 2  and the fourth lens unit B 4  move in the identical loci during zooming. 
     The third lens unit B 3  is the focus lens unit and moves from the object side toward the image side during focusing from the infinity object to the close object. Image blurring (the image position) is corrected by moving the second lens unit B 2  in a direction including a component substantially perpendicular to the optical axis. 
     Fifth Exemplary Embodiment 
     As illustrated in  FIGS. 9A and 9B , the zoom lens B 0  according to the fifth exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, the third lens unit B 3  having negative refractive power, and the fourth lens unit B 4  having negative refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, and the second lens unit B 2  to the fourth lens unit B 4  move toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases, the distance between the second lens unit B 2  and the third lens unit B 3  increases, and the distance between the third lens unit B 3  and the fourth lens unit B 4  decreases. The second lens unit B 2  and the fourth lens unit B 4  move in the identical loci during zooming. 
     The third lens unit B 3  is the focus lens unit, and moves from the object side toward the image side during focusing from the infinity object to the close object. Image blurring (the image position) is corrected by moving the part of the second lens unit B 2  (the fourth lens, the sub-unit B 2 A) on the object side in a direction including a component substantially perpendicular to the optical axis. 
     Sixth Exemplary Embodiment 
     As illustrated in  FIGS. 11A and 11B , the zoom lens B 0  according to the sixth exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, the third lens unit B 3  having negative refractive power, and the fourth lens unit B 4  having positive refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, and the second lens unit B 2 , the third lens unit B 3 , and the fourth lens unit B 4  move in the identical loci toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases. 
     The third lens unit B 3  is the focus lens unit, and moves from the object side toward the image side during focusing from the infinity object to the close object. Image blurring (the image position) is corrected by moving the part of the second lens unit B 2  (the fourth lens, the sub-unit B 2 A) on the object side in a direction including a component substantially perpendicular to the optical axis. 
     Seventh Exemplary Embodiment 
     As illustrated in  FIGS. 13A and 13B , the zoom lens B 0  according to the seventh exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, and the third lens unit B 3  having negative refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, the second lens unit B 2  moves toward the object side, and the third lens unit B 3  moves toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases, and the distance between the second lens unit B 2  and the third lens unit B 3  increases. 
     The third lens unit B 3  is the focus lens unit, and moves from the object side toward the image side during focusing from the infinity object to the close object. Image blurring (the image position) is corrected by moving the part of the second lens unit B 2  (the fourth lens, the sub-unit B 2 A) on the object side in a direction including a component substantially perpendicular to the optical axis. 
     Eighth Exemplary Embodiment 
     As illustrated in  FIGS. 15A and 15B , the zoom lens B 0  according to the eighth exemplary embodiment includes the first lens unit B 1  having negative refractive power, the second lens unit B 2  having positive refractive power, and the third lens unit B 3  having negative refractive power. 
     During zooming from the wide angle end to the telephoto end, the first lens unit B 1  moves toward the image side, the second lens unit B 2  moves toward the object side, and the third lens unit B 3  moves toward the object side. In this operation, the distance between the first lens unit B 1  and the second lens unit B 2  decreases, and the distance between the second lens unit B 2  and the third lens unit B 3  increases. 
     The third lens unit B 3  is the focus lens unit, and moves from the object side toward the image side during focusing from the infinity object to the close object. Image blurring (the image position) is corrected by moving the part of the second lens unit B 2  (the fourth lens, the sub-unit B 2 A) on the object side in a direction including a component substantially perpendicular to the optical axis. 
     Next, first to eighth numeric examples corresponding to the first to eighth exemplary embodiments, respectively, will be described. 
     In surface data of each of the first to eighth numeric examples, r represents the curvature radius of each optical surface, and d (mm) represents the axial distance (the distance in the optical axis) between an mth surface and an (m+1)th surface, where m is a number assigned to each surface and numbered from the light incidence side. Further, nd represents the refractive index for the d-line of each optical member, and νd represents the Abbe number of the optical member. The Abbe number νd of a certain material is expressed as: 
       ν d =( Nd− 1)/( NF−NC ),
 
     where Nd, NF, NC, and Ng are a refractive index in a d-line (587.56 nm), a refractive index in an F-line (486.1 nm), a refractive index in a C-line (656.3 nm), and a refractive index in a g-line (a wavelength of 435.835 nm), respectively, of the Fraunhofer&#39;s lines. 
     In each of the first to eighth numeric examples, each of a focal length (mm), a F-number, and a half angle of view (degree) is a value in the case of when the zoom lens B 0  according to the corresponding exemplary embodiment is focused on the infinity object. Back focus BF is an air equivalent length from the last lens surface to the image plane. A total lens length is a value calculated by adding the back focus BF to the distance in the optical axis from the first lens surface to the last lens surface. 
     In the surface data, “*” of the surface number indicates the surface having an aspherical shape. The aspherical shape is expressed by the following expression (1): 
     
       
         
           
             
               
                 
                   X 
                   = 
                   
                     
                       
                         
                           H 
                           2 
                         
                          
                         
                           / 
                         
                          
                         R 
                       
                       
                         1 
                         + 
                         
                           
                             1 
                             - 
                             
                               
                                 ( 
                                 
                                   1 
                                   + 
                                   K 
                                 
                                 ) 
                               
                                
                               
                                 
                                   ( 
                                   
                                     H 
                                      
                                     
                                       / 
                                     
                                      
                                     R 
                                   
                                   ) 
                                 
                                 2 
                               
                             
                           
                         
                       
                     
                     + 
                     
                       A 
                        
                       
                           
                       
                        
                       
                         4 
                         · 
                         
                           H 
                           4 
                         
                       
                     
                     + 
                     
                       A 
                        
                       
                           
                       
                        
                       
                         6 
                         · 
                         
                           H 
                           6 
                         
                       
                     
                     + 
                     
                       A 
                        
                       
                           
                       
                        
                       
                         8 
                         · 
                         
                           H 
                           8 
                         
                       
                     
                     + 
                     
                       A 
                        
                       
                           
                       
                        
                       
                         10 
                         · 
                         
                           H 
                           10 
                         
                       
                     
                     + 
                     
                       A 
                        
                       
                           
                       
                        
                       
                         12 
                         · 
                         
                           H 
                           12 
                         
                       
                     
                     + 
                     
                       A 
                        
                       
                           
                       
                        
                       
                         14 
                         · 
                         
                           H 
                           14 
                         
                       
                     
                     + 
                     
                       A 
                        
                       
                           
                       
                        
                       
                         16 
                         · 
                         
                           H 
                           16 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
     where X is an X-axis in the optical axis direction, H is an H-axis in the direction perpendicular to the optical axis, while a light traveling direction is positive, R is a paraxial curvature radius, K is a conic constant, and Aj is a jth-order aspherical surface coefficient. In the aspherical coefficient, “e−y” indicates 10 −y . 
     First Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 81.305 
                 1.15 
                 1.63854 
                 55.4 
                 31.11 
               
               
                  2 
                 14.228 
                 8.51 
                   
                   
                 23.92 
               
               
                  3* 
                 −1000.000 
                 2.00 
                 1.53110 
                 55.9 
                 23.61 
               
               
                  4* 
                 54.155 
                 0.70 
                   
                   
                 23.70 
               
               
                  5 
                 201.759 
                 2.26 
                 1.84666 
                 23.8 
                 23.47 
               
               
                  6 
                 −109.647 
                 (Variable) 
                   
                   
                 23.24 
               
               
                  7 
                 154.918 
                 1.80 
                 1.51742 
                 52.4 
                 10.00 
               
               
                  8 
                 −41.663 
                 1.69 
                   
                   
                 10.19 
               
               
                  9 (Stop) 
                 ∞ 
                 1.00 
                   
                   
                 10.33 
               
               
                 10 
                 13.449 
                 3.04 
                 1.59522 
                 67.7 
                 10.47 
               
               
                 11 
                 519.400 
                 (Variable) 
                   
                   
                 9.94 
               
               
                 12 
                 −462.121 
                 0.60 
                 1.84666 
                 23.8 
                 8.86 
               
               
                 13 
                 29.053 
                 (Variable) 
                   
                   
                 8.66 
               
               
                 14* 
                 −144.347 
                 1.64 
                 1.58313 
                 59.4 
                 9.90 
               
               
                 15 
                 −64.118 
                 (Variable) 
                   
                   
                 10.53 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Third Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −6.16999e−005 
                 A6 = 9.64091e−008 
               
               
                 A8 = −6.24666e−010 
                 A10 = 1.15838e−011 
                 A12 = 5.52161e−014 
               
            
           
           
               
            
               
                 Fourth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −7.58020e−005 
                 A6 = −6.07857e−010 
               
               
                 A8 = 1.24373e−009 
                 A10 = −5.09126e−012 
                 A12 = −7.700126−015 
               
            
           
           
               
            
               
                 Fourteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −8.02055e−005 
                 A6 = −6.36693e−007 
               
               
                 A8 = −8.04272e−010 
                 A10 = −6.04362e−011 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 2.82 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal length 
                 15.46 
                 24.00 
                 43.65 
               
               
                 F-number 
                 4.16 
                 4.92 
                 6.50 
               
               
                 Half Angle of View (Degree) 
                 38.73 
                 29.65 
                 17.38 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 96.84 
                 85.69 
                 84.27 
               
               
                 BF 
                 26.19 
                 34.03 
                 49.18 
               
               
                 d6 
                 36.48 
                 17.48 
                 0.92 
               
               
                 d11 
                 1.54 
                 1.60 
                 2.61 
               
               
                 d13 
                 8.25 
                 8.19 
                 7.18 
               
               
                 d15 
                 26.19 
                 34.03 
                 49.18 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −29.62 
                 14.62 
                 −0.18 
                 −13.24 
               
               
                 2 
                 7 
                 17.56 
                 7.52 
                 3.13 
                 −2.75 
               
               
                 3 
                 12 
                 −32.27 
                 0.60 
                 0.31 
                 −0.02 
               
               
                 4 
                 14 
                 196.35 
                 1.64 
                 1.85 
                 0.82 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −27.19 
               
               
                 2 
                 3 
                 −96.67 
               
               
                 3 
                 5 
                 84.19 
               
               
                 4 
                 7 
                 63.65 
               
               
                 5 
                 10 
                 23.14 
               
               
                 6 
                 12 
                 −32.27 
               
               
                 7 
                 14 
                 196.35 
               
               
                   
               
            
           
         
       
     
     Second Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 26.941 
                 1.00 
                 1.63854 
                 55.4 
                 24.79 
               
               
                  2 
                 12.045 
                 7.49 
                   
                   
                 20.24 
               
               
                  3* 
                 −1000.000 
                 1.70 
                 1.53110 
                 55.9 
                 19.64 
               
               
                  4* 
                 33.260 
                 0.40 
                   
                   
                 19.29 
               
               
                  5 
                 46.469 
                 1.94 
                 1.84666 
                 23.8 
                 19.03 
               
               
                  6 
                 174.749 
                 (Variable) 
                   
                   
                 18.63 
               
               
                  7 
                 139.916 
                 1.73 
                 1.69680 
                 55.5 
                 8.98 
               
               
                  8 
                 −44.483 
                 1.00 
                   
                   
                 9.12 
               
               
                  9 (Stop) 
                 ∞ 
                 1.50 
                   
                   
                 9.16 
               
               
                 10 
                 16.314 
                 2.57 
                 1.77250 
                 49.6 
                 9.23 
               
               
                 11 
                 156.410 
                 (Variable) 
                   
                   
                 8.76 
               
               
                 12 
                 −384.505 
                 0.70 
                 1.84666 
                 23.8 
                 7.92 
               
               
                 13 
                 20.582 
                 (Variable) 
                   
                   
                 7.71 
               
               
                 14* 
                 −312.236 
                 2.08 
                 1.53110 
                 55.9 
                 10.79 
               
               
                 15* 
                 −28.811 
                 (Variable) 
                   
                   
                 11.46 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Third Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −1.41463e−004 
                 A6 = 7.66013e−007 
               
               
                 A8 = −1.27190e−009 
                 A10 = −1.10963e−011 
               
            
           
           
               
            
               
                 Fourth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −1.69055e−004 
                 A6 = 8.63631e−007 
               
               
                 A8 = −2.53183e−009 
                 A10 = −7.27576e−012 
               
            
           
           
               
            
               
                 Fourteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −9.44164e−006 
                 A6 = 5.54551e−007 
               
               
                 A8 = −1.94972e−008 
                 A10 = 2.35602e−010 
               
            
           
           
               
            
               
                 Fifteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = 3.12388e−005 
                 A6 = 2.31800e−007 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 2.35 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal Length 
                 18.53 
                 30.00 
                 43.65 
               
               
                 F-number 
                 4.56 
                 5.48 
                 6.50 
               
               
                 Half Angle of View (Degree) 
                 33.78 
                 24.48 
                 17.38 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 89.11 
                 81.23 
                 81.40 
               
               
                 BF 
                 28.48 
                 38.21 
                 47.77 
               
               
                 d6 
                 28.48 
                 10.86 
                 1.48 
               
               
                 d11 
                 1.53 
                 1.64 
                 2.28 
               
               
                 d13 
                 8.52 
                 8.41 
                 7.77 
               
               
                 d15 
                 28.48 
                 38.21 
                 47.77 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −31.01 
                 12.52 
                 1.87 
                 −8.64 
               
               
                 2 
                 7 
                 16.38 
                 6.79 
                 2.58 
                 −2.47 
               
               
                 3 
                 12 
                 −23.06 
                 0.70 
                 0.36 
                 −0.02 
               
               
                 4 
                 14 
                 59.61 
                 2.08 
                 1.50 
                 0.14 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −35.03 
               
               
                 2 
                 3 
                 −60.57 
               
               
                 3 
                 5 
                 74.25 
               
               
                 4 
                 7 
                 48.63 
               
               
                 5 
                 10 
                 23.39 
               
               
                 6 
                 12 
                 −23.06 
               
               
                 7 
                 14 
                 59.61 
               
               
                   
               
            
           
         
       
     
     Third Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 35.854 
                 1.00 
                 1.77250 
                 49.6 
                 26.50 
               
               
                  2 
                 14.573 
                 7.47 
                   
                   
                 22.24 
               
               
                  3* 
                 −1000.000 
                 1.70 
                 1.53110 
                 55.9 
                 21.69 
               
               
                  4* 
                 45.253 
                 0.40 
                   
                   
                 21.52 
               
               
                  5 
                 42.410 
                 2.16 
                 1.85478 
                 24.8 
                 21.16 
               
               
                  6 
                 140.853 
                 (Variable) 
                   
                   
                 20.73 
               
               
                  7 
                 128.816 
                 1.73 
                 1.67790 
                 55.3 
                 9.08 
               
               
                  8 
                 −46.174 
                 1.00 
                   
                   
                 9.20 
               
               
                  9 (Stop) 
                 ∞ 
                 1.50 
                   
                   
                 9.21 
               
               
                 10 
                 15.569 
                 2.03 
                 1.88300 
                 40.8 
                 9.23 
               
               
                 11 
                 134.614 
                 (Variable) 
                   
                   
                 8.83 
               
               
                 12 
                 −133.172 
                 0.70 
                 1.84666 
                 23.8 
                 8.13 
               
               
                 13 
                 17.103 
                 (Variable) 
                   
                   
                 7.86 
               
               
                 14* 
                 −181.303 
                 2.43 
                 1.53110 
                 55.9 
                 9.56 
               
               
                 15* 
                 −26.048 
                 (Variable) 
                   
                   
                 10.37 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Third Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −1.42036e−004 
                 A6 = 6.81082e−007 
               
               
                 A8 = −1.27645e−009 
                 A10 = −2.59087e−012 
               
            
           
           
               
            
               
                 Fourth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −1.54470e−004 
                 A6 = 8.17822e−007 
               
               
                 A8 = −2.40245e−009 
                 A10 = 7.64264e−013 
               
            
           
           
               
            
               
                 Fourteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = 3.90803e−005 
                 A6 = 2.26763e−006 
               
               
                 A8 = −3.71828e−008 
                 A10 = 5.18172e−010 
               
            
           
           
               
            
               
                 Fifteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = 6.95347e−005 
                 A6 = 1.53424e−006 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 2.35 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal Length 
                 18.53 
                 30.00 
                 43.65 
               
               
                 F-number 
                 4.53 
                 5.43 
                 6.50 
               
               
                 Half Angle of View (Degree) 
                 33.78 
                 24.48 
                 17.38 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 92.00 
                 80.75 
                 81.34 
               
               
                 BF 
                 29.45 
                 38.60 
                 49.50 
               
               
                 d6 
                 32.32 
                 11.91 
                 1.60 
               
               
                 d11 
                 1.58 
                 1.58 
                 1.58 
               
               
                 d13 
                 6.54 
                 6.54 
                 6.54 
               
               
                 d15 
                 29.45 
                 38.60 
                 49.50 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −35.20 
                 12.73 
                 0.44 
                 −10.40 
               
               
                 2 
                 7 
                 14.75 
                 6.25 
                 2.72 
                 −1.98 
               
               
                 3 
                 12 
                 −17.86 
                 0.70 
                 0.34 
                 −0.04 
               
               
                 4 
                 14 
                 56.97 
                 2.43 
                 1.84 
                 0.26 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −32.45 
               
               
                 2 
                 3 
                 −81.47 
               
               
                 3 
                 5 
                 70.28 
               
               
                 4 
                 7 
                 50.34 
               
               
                 5 
                 10 
                 19.78 
               
               
                 6 
                 12 
                 −17.86 
               
               
                 7 
                 14 
                 56.97 
               
               
                   
               
            
           
         
       
     
     Fourth Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 45.893 
                 1.00 
                 1.63854 
                 55.4 
                 27.09 
               
               
                  2 
                 14.386 
                 7.03 
                   
                   
                 22.30 
               
               
                  3 
                 −85.298 
                 1.70 
                 1.53110 
                 55.9 
                 21.78 
               
               
                  4* 
                 97.643 
                 0.40 
                   
                   
                 21.12 
               
               
                  5 
                 23.337 
                 2.24 
                 1.84666 
                 23.8 
                 20.54 
               
               
                  6 
                 34.716 
                 (Variable) 
                   
                   
                 19.79 
               
               
                  7 (Stop) 
                 ∞ 
                 1.00 
                   
                   
                 9.02 
               
               
                  8* 
                 16.308 
                 2.56 
                 1.77250 
                 49.6 
                 9.36 
               
               
                  9 
                 −58.463 
                 (Variable) 
                   
                   
                 9.12 
               
               
                 10 
                 42172.073 
                 0.60 
                 1.80810 
                 22.8 
                 8.03 
               
               
                 11 
                 19.038 
                 (Variable) 
                   
                   
                 7.82 
               
               
                 12* 
                 −263.369 
                 2.08 
                 1.53110 
                 55.9 
                 10.58 
               
               
                 13 
                 −27.990 
                 (Variable) 
                   
                   
                 11.27 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Fourth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −4.47785e−006 
                 A6 = 4.80655e−008 
               
               
                 A8 = −5.32262e−010 
                 A10 = 1.27701e−012 
               
            
           
           
               
            
               
                 Eighth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −3.43112e−005 
                 A6 = 3.14927e−008 
               
               
                 A8 = −2.95172e−009 
                 A10 = 4.26192e−011 
               
            
           
           
               
            
               
                 Twelfth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −3.22505e−005 
                 A6 = 1.56251e−007 
               
               
                 A8 = −1.96015e−008 
                 A10 = 3.12929e−010 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 2.35 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal Length 
                 18.53 
                 26.00 
                 43.60 
               
               
                 F-number 
                 4.56 
                 5.17 
                 6.50 
               
               
                 Half Angle of View (Degree) 
                 33.79 
                 27.72 
                 17.40 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 91.32 
                 83.11 
                 80.48 
               
               
                 BF 
                 29.73 
                 36.16 
                 48.88 
               
               
                 d6 
                 32.64 
                 18.00 
                 2.64 
               
               
                 d9 
                 2.37 
                 2.28 
                 2.75 
               
               
                 d11 
                 7.98 
                 8.08 
                 7.61 
               
               
                 d13 
                 29.73 
                 36.16 
                 48.88 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −34.13 
                 12.37 
                 1.21 
                 −8.90 
               
               
                 2 
                 7 
                 16.76 
                 3.56 
                 1.32 
                 −1.14 
               
               
                 3 
                 10 
                 −23.57 
                 0.60 
                 0.33 
                 0.00 
               
               
                 4 
                 12 
                 58.79 
                 2.08 
                 1.51 
                 0.16 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −33.23 
               
               
                 2 
                 3 
                 −85.45 
               
               
                 3 
                 5 
                 77.13 
               
               
                 4 
                 8 
                 16.76 
               
               
                 5 
                 10 
                 −23.57 
               
               
                 6 
                 12 
                 58.79 
               
               
                   
               
            
           
         
       
     
     Fifth Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 51.714 
                 1.15 
                 1.72916 
                 54.7 
                 30.45 
               
               
                  2 
                 15.131 
                 9.48 
                   
                   
                 24.47 
               
               
                  3* 
                 −68.368 
                 2.00 
                 1.53110 
                 55.9 
                 23.99 
               
               
                  4* 
                 −1234.568 
                 0.30 
                   
                   
                 24.30 
               
               
                  5 
                 −202.690 
                 2.04 
                 1.84666 
                 23.8 
                 24.02 
               
               
                  6 
                 −65.810 
                 (Variable) 
                   
                   
                 23.91 
               
               
                  7 
                 211.787 
                 1.75 
                 1.60311 
                 60.6 
                 10.34 
               
               
                  8 
                 −48.064 
                 1.71 
                   
                   
                 10.50 
               
               
                  9 (Stop) 
                 ∞ 
                 1.00 
                   
                   
                 10.59 
               
               
                 10 
                 12.750 
                 2.89 
                 1.51823 
                 58.9 
                 10.70 
               
               
                 11 
                 −61.135 
                 (Variable) 
                   
                   
                 10.28 
               
               
                 12 
                 −53.415 
                 0.60 
                 1.85478 
                 24.8 
                 9.18 
               
               
                 13 
                 52.610 
                 (Variable) 
                   
                   
                 8.98 
               
               
                 14* 
                 444.819 
                 1.50 
                 1.53110 
                 55.9 
                 9.76 
               
               
                 15 
                 95.657 
                 (Variable) 
                   
                   
                 10.33 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Third Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −6.37596e−005 
                 A6 = 5.59365e−007 
               
               
                 A8 = −6.75504e−009 
                 A10 = 4.19523e−011 
                 A12 = −1.04577e−013 
               
            
           
           
               
            
               
                 Fourth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −6.85609e−005 
                 A6 = 4.64163e−007 
               
               
                 A8 = −5.211226−009 
                 A10 = 2.99013e−011 
                 A12 = −7.12555e−014 
               
            
           
           
               
            
               
                 Fourteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −1.15845e−004 
                 A6 = −7.75571e−007 
               
               
                 A8 = −3.94565e−009 
                 A10 = −5.60854e−011 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 2.66 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal Length 
                 16.41 
                 24.00 
                 43.65 
               
               
                 F-number 
                 4.21 
                 4.90 
                 6.50 
               
               
                 Half Angle of View (Degree) 
                 37.08 
                 29.65 
                 17.38 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 99.00 
                 87.77 
                 83.61 
               
               
                 BF 
                 24.60 
                 31.13 
                 45.64 
               
               
                 d6 
                 39.49 
                 21.74 
                 3.07 
               
               
                 d11 
                 1.49 
                 1.49 
                 2.08 
               
               
                 d13 
                 8.99 
                 9.00 
                 8.40 
               
               
                 d15 
                 24.60 
                 31.13 
                 45.64 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −32.74 
                 14.97 
                 −0.48 
                 −14.20 
               
               
                 2 
                 7 
                 16.29 
                 7.36 
                 3.46 
                 −2.41 
               
               
                 3 
                 12 
                 −30.93 
                 0.60 
                 0.16 
                 −0.16 
               
               
                 4 
                 14 
                 −229.80 
                 1.50 
                 1.25 
                 0.27 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −29.73 
               
               
                 2 
                 3 
                 −136.36 
               
               
                 3 
                 5 
                 114.32 
               
               
                 4 
                 7 
                 65.12 
               
               
                 5 
                 10 
                 20.63 
               
               
                 6 
                 12 
                 −30.93 
               
               
                 7 
                 14 
                 −229.80 
               
               
                   
               
            
           
         
       
     
     Sixth Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 32.515 
                 1.00 
                 1.67790 
                 55.3 
                 25.08 
               
               
                  2 
                 13.169 
                 6.71 
                   
                   
                 20.91 
               
               
                  3* 
                 −1000.000 
                 1.70 
                 1.53110 
                 55.9 
                 20.46 
               
               
                  4* 
                 45.486 
                 0.40 
                   
                   
                 20.10 
               
               
                  5 
                 23.627 
                 2.02 
                 2.00069 
                 25.5 
                 19.69 
               
               
                  6 
                 34.676 
                 (Variable) 
                   
                   
                 19.02 
               
               
                  7 
                 115.005 
                 1.73 
                 1.72916 
                 54.7 
                 9.08 
               
               
                  8 
                 −48.763 
                 1.00 
                   
                   
                 9.14 
               
               
                  9 (Stop) 
                 ∞ 
                 1.50 
                   
                   
                 9.05 
               
               
                 10 
                 14.904 
                 2.63 
                 1.72916 
                 54.7 
                 8.93 
               
               
                 11 
                 −272.635 
                 (Variable) 
                   
                   
                 8.42 
               
               
                 12 
                 −35.401 
                 0.70 
                 1.90366 
                 31.3 
                 7.72 
               
               
                 13 
                 17.894 
                 (Variable) 
                   
                   
                 7.53 
               
               
                 14* 
                 −80.549 
                 2.34 
                 1.53110 
                 55.9 
                 8.98 
               
               
                 15* 
                 −13.809 
                 (Variable) 
                   
                   
                 9.84 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Third Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −2.82744e−005 
                 A6 = −4.01528e−007 
               
               
                 A8 = 4.70130e−009 
                 A10 = −1.93064e−011 
               
            
           
           
               
            
               
                 Fourth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −3.88075e−005 
                 A6 = −4.28587e−007 
               
               
                 A8 = 4.87774e−009 
                 A10 = −2.07859e−011 
               
            
           
           
               
            
               
                 Fourteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −4.11964e−005 
                 A6 = 6.94293e−007 
               
               
                 A8 = −5.20928e−008 
                 A10 = 1.13182e−009 
               
            
           
           
               
            
               
                 Fifteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −8.49430e−006 
                 A6 = −1.54892e−007 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 2.18 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal Length 
                 20.01 
                 27.00 
                 43.65 
               
               
                 F-number 
                 4.60 
                 5.15 
                 6.50 
               
               
                 Half Angle of View (Degree) 
                 31.79 
                 26.84 
                 17.38 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 92.00 
                 84.32 
                 83.15 
               
               
                 BF 
                 33.77 
                 39.37 
                 52.69 
               
               
                 d6 
                 30.31 
                 17.03 
                 2.54 
               
               
                 d11 
                 1.63 
                 1.63 
                 1.63 
               
               
                 d13 
                 4.57 
                 4.57 
                 4.57 
               
               
                 d15 
                 33.77 
                 39.37 
                 52.69 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −35.80 
                 11.83 
                 1.24 
                 −8.34 
               
               
                 2 
                 7 
                 14.40 
                 6.86 
                 2.83 
                 −2.33 
               
               
                 3 
                 12 
                 −13.07 
                 0.70 
                 0.24 
                 −0.12 
               
               
                 4 
                 14 
                 31.00 
                 2.34 
                 1.82 
                 0.31 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −33.35 
               
               
                 2 
                 3 
                 −81.87 
               
               
                 3 
                 5 
                 67.89 
               
               
                 4 
                 7 
                 47.17 
               
               
                 5 
                 10 
                 19.46 
               
               
                 6 
                 12 
                 −13.07 
               
               
                 7 
                 14 
                 31.00 
               
               
                   
               
            
           
         
       
     
     Seventh Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 48.059 
                 1.00 
                 1.63854 
                 55.4 
                 26.32 
               
               
                  2 
                 14.114 
                 7.33 
                   
                   
                 21.64 
               
               
                  3* 
                 −1000.000 
                 1.70 
                 1.53110 
                 55.9 
                 21.08 
               
               
                  4* 
                 51.376 
                 0.40 
                   
                   
                 20.96 
               
               
                  5 
                 49.503 
                 1.99 
                 1.84666 
                 23.8 
                 20.55 
               
               
                  6 
                 177.062 
                 (Variable) 
                   
                   
                 20.15 
               
               
                  7 
                 127.256 
                 1.73 
                 1.67790 
                 55.3 
                 9.12 
               
               
                  8 
                 −47.359 
                 1.00 
                   
                   
                 9.25 
               
               
                  9 (Stop) 
                 ∞ 
                 1.50 
                   
                   
                 9.27 
               
               
                 10 
                 17.235 
                 2.61 
                 1.80400 
                 46.6 
                 9.31 
               
               
                 11 
                 358.823 
                 (Variable) 
                   
                   
                 8.84 
               
               
                 12 
                 −117.524 
                 0.70 
                 1.84666 
                 23.8 
                 8.08 
               
               
                 13 
                 21.736 
                 7.12 
                   
                   
                 7.87 
               
               
                 14* 
                 −221.529 
                 2.41 
                 1.53110 
                 55.9 
                 10.05 
               
               
                 15* 
                 −28.819 
                 (Variable) 
                   
                   
                 10.82 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Third Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −1.24978e−004 
                 A6 = 2.71294e−007 
               
               
                 A8 = 1.41979e−009 
                 A10 = −9.72356e−012 
               
            
           
           
               
            
               
                 Fourth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = −1.37193e−004 
                 A6 = 3.71703e−007 
               
               
                 A8 = 7.25801e−010 
                 A10 = −7.69387e−012 
               
            
           
           
               
            
               
                 Fourteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = 4.49135e−005 
                 A6 = 1.54680e−006 
               
               
                 A8 = −2.35020e−008 
                 A10 = 2.913196−010 
               
            
           
           
               
            
               
                 Fifteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = 7.57248e−005 
                 A6 = 1.14052e−006 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 2.36 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal Length 
                 18.53 
                 27.00 
                 43.65 
               
               
                 F-number 
                 4.56 
                 5.23 
                 6.50 
               
               
                 Half Angle of View (Degree) 
                 33.79 
                 26.84 
                 17.38 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 92.00 
                 82.86 
                 81.68 
               
               
                 BF 
                 29.46 
                 36.42 
                 48.75 
               
               
                 d6 
                 31.48 
                 15.36 
                 1.50 
               
               
                 d11 
                 1.56 
                 1.59 
                 1.93 
               
               
                 d15 
                 29.46 
                 36.42 
                 48.75 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −33.74 
                 12.42 
                 0.44 
                 −10.21 
               
               
                 2 
                 7 
                 16.19 
                 6.84 
                 2.71 
                 −2.37 
               
               
                 3 
                 12 
                 −42.61 
                 10.23 
                 −5.84 
                 −17.47 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −31.66 
               
               
                 2 
                 3 
                 −91.96 
               
               
                 3 
                 5 
                 80.58 
               
               
                 4 
                 7 
                 51.12 
               
               
                 5 
                 10 
                 22.44 
               
               
                 6 
                 12 
                 −21.62 
               
               
                 7 
                 14 
                 62.11 
               
               
                   
               
            
           
         
       
     
     Eighth Numeric Example 
       
     
       
         
           
               
             
               
                   
               
             
            
               
                 Surface Data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Surface 
                   
                   
                   
                   
                 Effective 
               
               
                 Number 
                 r 
                 d 
                 nd 
                 νd 
                 Diameter 
               
               
                   
               
               
                  1 
                 26.077 
                 1.00 
                 1.48749 
                 70.2 
                 20.69 
               
               
                  2 
                 11.855 
                 6.10 
                   
                   
                 17.78 
               
               
                  3* 
                 −46.388 
                 1.70 
                 1.53110 
                 55.9 
                 17.07 
               
               
                  4 
                 66.382 
                 0.40 
                   
                   
                 16.45 
               
               
                  5 
                 18.651 
                 2.51 
                 1.51742 
                 52.4 
                 16.13 
               
               
                  6 
                 49.111 
                 (Variable) 
                   
                   
                 15.55 
               
               
                  7 (Stop) 
                 ∞ 
                 1.00 
                   
                   
                 4.92 
               
               
                  8 
                 38.354 
                 1.54 
                 1.49700 
                 81.5 
                 5.00 
               
               
                  9 
                 −53.188 
                 1.47 
                   
                   
                 5.01 
               
               
                 10 
                 8.415 
                 1.67 
                 1.56732 
                 42.8 
                 4.95 
               
               
                 11 
                 27.462 
                 (Variable) 
                   
                   
                 4.61 
               
               
                 12 
                 15.014 
                 0.60 
                 1.82115 
                 24.1 
                 4.57 
               
               
                 13* 
                 7.963 
                 (Variable) 
                   
                   
                 4.57 
               
               
                 Image Plane 
                 ∞ 
               
               
                   
               
            
           
           
               
            
               
                 Aspherical Data 
               
               
                   
               
               
                 Third Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = 2.68514e−007 
                 A6 = 3.76986e−008 
               
               
                 A8 = −7.83455e−010 
                 A10 = 4.73817e−012 
               
            
           
           
               
            
               
                 Thirteenth Surface 
               
            
           
           
               
               
               
            
               
                 K = 0 
                 A4 = 1.28808e−004 
                 A6 = −1.62031e−005 
               
               
                 A8 = 3.98366e−006 
                 A10 = −2.76591e−007 
               
               
                   
               
            
           
           
               
            
               
                 Various Data 
               
               
                 Zoom Ratio 1.45 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-Angle 
                 Intermediate 
                 Telephoto 
               
               
                   
               
               
                 Focal Length 
                 24.50 
                 26.73 
                 35.50 
               
               
                 F-number 
                 9.41 
                 9.73 
                 11.00 
               
               
                 Half Angle of View (Degree) 
                 26.84 
                 27.07 
                 21.05 
               
               
                 Image Height 
                 12.40 
                 13.66 
                 13.66 
               
               
                 Total Lens Length 
                 85.00 
                 82.28 
                 76.68 
               
               
                 BF 
                 36.70 
                 38.07 
                 43.53 
               
               
                 d6 
                 28.80 
                 24.69 
                 13.57 
               
               
                 d11 
                 1.50 
                 1.52 
                 1.59 
               
               
                 d13 
                 36.70 
                 38.07 
                 43.53 
               
               
                   
               
            
           
           
               
            
               
                 Zoom Lens Unit Data 
               
            
           
           
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                 Front 
                 Rear 
               
               
                   
                   
                   
                 Lens 
                 Principal 
                 Principal 
               
               
                   
                 Start 
                 Focal 
                 Configuration 
                 Point 
                 Point 
               
               
                 Unit 
                 Surface 
                 Length 
                 Length 
                 Position 
                 Position 
               
               
                   
               
               
                 1 
                 1 
                 −41.72 
                 11.71 
                 1.67 
                 −8.18 
               
               
                 2 
                 7 
                 14.56 
                 5.69 
                 2.57 
                 −2.01 
               
               
                 3 
                 12 
                 −21.47 
                 0.60 
                 0.73 
                 0.39 
               
               
                   
               
            
           
           
               
            
               
                 Single Lens Data 
               
            
           
           
               
               
               
            
               
                 Lens 
                 Start Surface 
                 Focal Length 
               
               
                   
               
               
                 1 
                 1 
                 −45.64 
               
               
                 2 
                 3 
                 −51.15 
               
               
                 3 
                 5 
                 56.53 
               
               
                 4 
                 8 
                 45.09 
               
               
                 5 
                 10 
                 20.73 
               
               
                 6 
                 12 
                 −21.47 
               
               
                   
               
            
           
         
       
     
     Various values in each of the first to eighth numeric examples are summarized in the following Table 1. 
     
       
         
           
               
               
               
               
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 First 
                 Second 
                 Third 
                 Fourth 
                 Fifth 
                 Sixth 
                 Seventh 
                 Eighth 
               
               
                   
                 Example 
                 Example 
                 Example 
                 Example 
                 Example 
                 Example 
                 Example 
                 Example 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Nd_G1 
                 1.6385 
                 1.6385 
                 1.7725 
                 1.6385 
                 1.7292 
                 1.6779 
                 1.6385 
                 1.4875 
               
               
                 SF_B3n 
                 −0.88 
                 −0.90 
                 −0.77 
                 −1.00 
                 −0.01 
                 −0.33 
                 −0.69 
                 −3.26 
               
               
                 |f1|/fw 
                 1.92 
                 1.67 
                 1.90 
                 1.84 
                 2.00 
                 1.79 
                 1.82 
                 1.70 
               
               
                 f2/fw 
                 1.14 
                 0.88 
                 0.80 
                 0.90 
                 0.99 
                 0.72 
                 0.87 
                 0.59 
               
               
                 f3/f1 
                 1.09 
                 0.74 
                 0.51 
                 0.69 
                 0.94 
                 0.37 
                 1.26 
                 0.51 
               
               
                 νd_B3n 
                 23.78 
                 23.78 
                 23.78 
                 22.76 
                 24.80 
                 31.32 
                 23.78 
                 24.06 
               
               
                   
               
            
           
         
       
     
     [Image Capturing Apparatus] 
     Next, a description will be given of an exemplary embodiment with reference to  FIG. 17  in which a digital still camera (an image capturing apparatus)  10  employs the zoom lens according to any of the exemplary embodiments as an imaging optical system.  FIG. 17  illustrates a camera body  13  and an image-capturing optical system  11  including the zoom lens B 0  described in any of the first to eighth exemplary embodiments. A solid-state image sensor (a photoelectric conversion element)  12 , such as a CCD sensor and CMOS sensor, is disposed in the camera body  13 . The solid-state image sensor  12  receives an optical image formed by the image-capturing optical system  11 , and photoelectrically converts the received optical image. The camera body  13  may be a single-lens reflex camera having a quick turn mirror, or may be a mirrorless camera not having a quick turn mirror. 
     In the above-described way, the zoom lens according to any of the exemplary embodiments of the disclosure is applied to the image capturing apparatus, such as a digital still camera, whereby an image capturing apparatus having excellent optical performance while being light in weight can be obtained. 
     The zoom lens according to each of the above-described exemplary embodiments is not limited to the image capturing apparatus, such as a digital still camera, and is applicable to various optical apparatuses, such as a telescope. 
     Some exemplary embodiments and examples of the disclosure are described above, but the disclosure is not limited to these exemplary embodiments and examples, and various combinations, alterations, and modifications can be made without departing from the scope of the disclosure. 
     While the disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2019-215441, filed Nov. 28, 2019, which is hereby incorporated by reference herein in its entirety.