Patent Publication Number: US-2013242142-A1

Title: Zoom lens system, interchangeable lens apparatus and camera system

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based on application No. 2012-057034 filed in Japan on Mar. 14, 2012 and application No. 2013-009277 filed in Japan on Jan. 22, 2013, the contents of which are hereby incorporated by reference. 
     BACKGROUND 
     1. Field 
     The present disclosure relates to zoom lens systems, interchangeable lens apparatuses, and camera systems. 
     2. Description of the Related Art 
     In recent years, interchangeable-lens type digital camera systems (also referred to simply as “camera systems”, hereinafter) have been spreading rapidly. Such interchangeable-lens type digital camera systems realize: taking of high-sensitive and high-quality images; high-speed focusing and high-speed image processing after image taking; and easy replacement of an interchangeable lens apparatus in accordance with a desired scene. Meanwhile, an interchangeable lens apparatus having a zoom lens system that forms an optical image with variable magnification is popular because it allows free change of focal length without the necessity of lens replacement. 
     Zoom lens systems having excellent optical performance from a wide-angle limit to a telephoto limit have been desired as zoom lens systems to be used in interchangeable lens apparatuses. For example, various kinds of zoom lens systems each having a multiple-unit construction in which a positive lens unit is located closest to an object side have been proposed. 
     Japanese Laid-Open Patent Publication No. 08-327905 discloses a zoom lens having a five-unit construction of positive, negative, positive, negative, and positive, in which the relationship between the focal length of the first lens unit and the focal length of the second lens unit, and the relationship between the focal length of the fourth lens unit and the focal length of the fifth lens unit are set forth. 
     Japanese Laid-Open Patent Publication No. 10-039211 discloses a zoom lens having a five-unit construction of positive, negative, positive, negative, and positive, in which the second lens unit and the fourth lens unit move at the time of magnification change, and the magnification of the second lens unit and the magnification of the fourth lens unit individually become 1.0× at almost the same time. 
     Japanese Laid-Open Patent Publication No. 2002-228931 discloses a zoom lens having a five-unit construction of positive, negative, positive, negative, and positive, in which the constructions of the first lens unit, the second lens unit, the third lens unit, and the fourth lens unit, and the relationship between the magnification of the second lens unit and the magnification of the third lens unit are set forth. 
     Japanese Laid-Open Patent Publication No. 2009-109630 discloses a zoom lens having a two-unit construction of positive and negative, in which the second lens unit moves at the time of magnification change, and the refractive index and the Abbe number of a material constituting the first lens unit are set forth. 
     Japanese Laid-Open Patent Publication No. 2011-197472 discloses a zoom lens including a plurality of lens units that move at the time of magnification change, in which at least two of the lens units are focusing lens units, and an exit pupil position at a wide-angle limit, a focal length of a wobbling lens unit, and the like are set forth. 
     SUMMARY 
     The present disclosure provides a compact and lightweight zoom lens system having a short overall length of lens system as well as excellent optical performance. Further, the present disclosure provides an interchangeable lens apparatus and a camera system each employing the zoom lens system. 
     The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     a zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, 
     the zoom lens system, in order from an object side to an image side, comprising: 
     a first lens unit having positive optical power; and 
     a second lens unit having negative optical power, wherein 
     the first lens unit is composed of two or less lens elements, 
     in zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit is fixed with respect to an image surface, and 
     the following conditions (1) and (2) are satisfied: 
         L   T   /f   T &lt;1.45  (1)
 
       2.6&lt;( f   T   /f   W )×(tan(θ W )) 2   (2)
 
     where, 
     L T  is an overall length of lens system at a telephoto limit (a distance from a most object side surface of the first lens unit to the image surface, at a telephoto limit), 
     f T  is a focal length of the entire system at the telephoto limit, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     θ W  is a half view angle (°) at the wide-angle limit. 
     The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     an interchangeable lens apparatus comprising: 
     a zoom lens system; and 
     a lens mount section which is connectable to a camera body including an image sensor for receiving an optical image formed by the zoom lens system and converting the optical image into an electric image signal, wherein 
     the zoom lens system is a zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, 
     the zoom lens system, in order from an object side to an image side, comprising: 
     a first lens unit having positive optical power; and 
     a second lens unit having negative optical power, wherein 
     the first lens unit is composed of two or less lens elements, 
     in zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit is fixed with respect to an image surface, and 
     the following conditions (1) and (2) are satisfied: 
         L   T   /f   T &lt;1.45  (1)
 
       2.6&lt;( f   T   /f   W )×(tan(θ W )) 2   (2)
 
     where, 
     L T  is an overall length of lens system at a telephoto limit (a distance from a most object side surface of the first lens unit to the image surface, at a telephoto limit), 
     f T  is a focal length of the entire system at the telephoto limit, f W  is a focal length of the entire system at a wide-angle limit, and 
     θ W  is a half view angle (°) at the wide-angle limit. 
     The novel concepts disclosed herein were achieved in order to solve the foregoing problems in the related art, and herein is disclosed: 
     a camera system comprising: 
     an interchangeable lens apparatus including a zoom lens system; and 
     a camera body which is detachably connected to the interchangeable lens apparatus via a camera mount section, and includes an image sensor for receiving an optical image formed by the zoom lens system and converting the optical image into an electric image signal, wherein 
     the zoom lens system is a zoom lens system having a plurality of lens units, each lens unit being composed of at least one lens element, 
     the zoom lens system, in order from an object side to an image side, comprising: 
     a first lens unit having positive optical power; and 
     a second lens unit having negative optical power, wherein 
     the first lens unit is composed of two or less lens elements, 
     in zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit is fixed with respect to an image surface, and 
     the following conditions (1) and (2) are satisfied: 
         L   T   /f   T &lt;1.45  (1)
 
       2.6&lt;( f   T   /f   W )×(tan(θ W )) 2   (2)
 
     where, 
     L T  is an overall length of lens system at a telephoto limit (a distance from a most object side surface of the first lens unit to the image surface, at a telephoto limit), 
     f T  is a focal length of the entire system at the telephoto limit, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     θ W  is a half view angle (°) at the wide-angle limit. 
     The zoom lens system according to the present disclosure is compact and lightweight, and has a short overall length of lens system as well as excellent optical performance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This and other objects and features of the present disclosure will become clear from the following description, taken in conjunction with the exemplary embodiments with reference to the accompanied drawings in which: 
         FIG. 1  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 1 (Numerical Example 1); 
         FIG. 2  is a longitudinal aberration diagram of an infinity in-focus condition of a zoom lens system according to Numerical Example 1; 
         FIG. 3  is a lateral aberration diagram of a zoom lens system according to Numerical Example 1 at a telephoto limit in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 4  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 2 (Numerical Example 2); 
         FIG. 5  is a longitudinal aberration diagram of an infinity in-focus condition of a zoom lens system according to Numerical Example 2; 
         FIG. 6  is a lateral aberration diagram of a zoom lens system according to Numerical Example 2 at a telephoto limit in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 7  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 3 (Numerical Example 3); 
         FIG. 8  is a longitudinal aberration diagram of an infinity in-focus condition of a zoom lens system according to Numerical Example 3; 
         FIG. 9  is a lateral aberration diagram of a zoom lens system according to Numerical Example 3 at a telephoto limit in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 10  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 4 (Numerical Example 4); 
         FIG. 11  is a longitudinal aberration diagram of an infinity in-focus condition of a zoom lens system according to Numerical Example 4; 
         FIG. 12  is a lateral aberration diagram of a zoom lens system according to Numerical Example 4 at a telephoto limit in a basic state where image blur compensation is not performed and in an image blur compensation state; 
         FIG. 13  is a lens arrangement diagram showing an infinity in-focus condition of a zoom lens system according to Embodiment 5 (Numerical Example 5); 
         FIG. 14  is a longitudinal aberration diagram of an infinity in-focus condition of a zoom lens system according to Numerical Example 5; 
         FIG. 15  is a lateral aberration diagram of a zoom lens system according to Numerical Example 5 at a telephoto limit in a basic state where image blur compensation is not performed and in an image blur compensation state; and 
         FIG. 16  is a schematic construction diagram of an interchangeable-lens type digital camera system according to Embodiment 6. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments will be described with reference to the drawings as appropriate. However, descriptions more detailed than necessary may be omitted. For example, detailed description of already well known matters or description of substantially identical configurations may be omitted. This is intended to avoid redundancy in the description below, and to facilitate understanding of those skilled in the art. 
     It should be noted that the applicants provide the attached drawings and the following description so that those skilled in the art can fully understand this disclosure. Therefore, the drawings and description are not intended to limit the subject defined by the claims. 
     Embodiments 1 to 5 
       FIGS. 1 ,  4 ,  7 ,  10 , and  13  are lens arrangement diagrams of zoom lens systems according to Embodiments 1 to 5, respectively. 
     Each of  FIGS. 1 ,  4 ,  7 ,  10 , and  13  shows a zoom lens system in an infinity in-focus condition. In each Fig., part (a) shows a lens configuration at a wide-angle limit (in the minimum focal length condition: focal length f w ), part (b) shows a lens configuration at a middle position (in an intermediate focal length condition: focal length f M =√(f w *f T )), and part (c) shows a lens configuration at a telephoto limit (in the maximum focal length condition: focal length f T ). Further, in each Fig., each bent arrow located between part (a) and part (b) indicates a line obtained by connecting the positions of each lens unit respectively at a wide-angle limit, a middle position and a telephoto limit, in order from the top. In the part between the wide-angle limit and the middle position and the part between the middle position and the telephoto limit, the positions are connected simply with a straight line, and hence this line does not indicate actual motion of each lens unit. Further, in each Fig., an arrow imparted to a lens unit indicates focusing from an infinity in-focus condition to a close-object in-focus condition. That is, in  FIG. 1 , the arrow indicates a moving direction of a fourth lens unit G 4  described later, in focusing from an infinity in-focus condition to a close-object in-focus condition. In  FIGS. 4 ,  7 ,  10 , and  13 , the arrow indicates a moving direction of a fifth lens unit G 5  described later, in focusing from an infinity in-focus condition to a close-object in-focus condition. 
     The zoom lens system according to Embodiment 1, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having positive optical power, a fourth lens unit G 4  having negative optical power, and a fifth lens unit G 5  having positive optical power. Each of the zoom lens systems according to Embodiments 2 to 4, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having positive optical power, a fourth lens unit G 4  having positive optical power, a fifth lens unit G 5  having negative optical power, and a sixth lens unit G 6  having positive optical power. The zoom lens system according to Embodiment 5, in order from the object side to the image side, comprises a first lens unit G 1  having positive optical power, a second lens unit G 2  having negative optical power, a third lens unit G 3  having negative optical power, a fourth lens unit G 4  having positive optical power, a fifth lens unit G 5  having negative optical power, and a sixth lens unit G 6  having positive optical power. 
     In  FIGS. 1 ,  4 ,  7 ,  10 , and  13 , an asterisk “*” imparted to a particular surface indicates that the surface is aspheric. In each Fig., symbol (+) or (−) imparted to the symbol of each lens unit corresponds to the sign of the optical power of the lens unit. In each Fig., a straight line located on the most right-hand side indicates the position of an image surface S. Further, as shown in each Fig., an aperture diaphragm A is provided between the second lens unit G 2  and the third lens unit G 3 . 
     Embodiment 1 
     As shown in  FIG. 1 , the first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; and a bi-convex second lens element L 2 . The first lens element L 1  and the second lens element L 2  are cemented with each other. The second lens element L 2  has an aspheric image side surface. 
     The second lens unit G 2 , in order from the object side to the image side, comprises: a bi-concave third lens element L 3 ; a bi-concave fourth lens element L 4 ; a bi-convex fifth lens element L 5 ; and a negative meniscus sixth lens element L 6  with the convex surface facing the image side. Among these, the fifth lens element L 5  and the sixth lens element L 6  are cemented with each other. The third lens element L 3  is a hybrid lens element comprising: a lens element formed of a glass material; and a negative meniscus transparent resin layer with the convex surface facing the image side, which is formed of an ultraviolet curable resin and is cemented to an object side surface of the lens element. The third lens element L 3  has an aspheric object side surface. 
     The hybrid lens element of the present disclosure has an aspheric surface facing the transparent resin layer side. Thereby, it is possible to form a large-diameter aspheric surface that is difficult to form by press molding when only a glass material is used. Further, as compared to the case where a lens element is formed of a resin only, the hybrid lens element is stable in terms of both refractive index change and shape change against temperature change. Therefore, it is possible to obtain a lens element having a high refractive index. 
     The third lens unit G 3 , in order from the object side to the image side, comprises: a bi-convex seventh lens element L 7 ; a bi-convex eighth lens element L 8 ; a bi-concave ninth lens element L 9 ; a bi-convex tenth lens element L 10 ; and a negative meniscus eleventh lens element L 11  with the convex surface facing the image side. Among these, the eighth lens element L 8  and the ninth lens element L 9  are cemented with each other, and the tenth lens element L 10  and the eleventh lens element L 11  are cemented with each other. The eighth lens element L 8  has an aspheric object side surface. The tenth lens element L 10  has an aspheric object side surface. 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a positive meniscus twelfth lens element L 12  with the convex surface facing the image side; and a bi-concave thirteenth lens element L 13 . The twelfth lens element L 12  and the thirteenth lens element L 13  are cemented with each other. The thirteenth lens element L 13  has an aspheric image side surface. 
     The fifth lens unit G 5 , in order from the object side to the image side, comprises: a bi-convex fourteenth lens element L 14 ; and a negative meniscus fifteenth lens element L 15  with the convex surface facing the image side. The fourteenth lens element L 14  and the fifteenth lens element L 15  are cemented with each other. The fourteenth lens element L 14  has an aspheric object side surface. 
     In zooming from a wide-angle limit to a telephoto limit at the time of image taking, the first lens unit G 1  does not move, the second lens unit G 2  moves to the image side, the aperture diaphragm A does not move, the third lens unit G 3  moves to the object side, the fourth lens unit G 4  moves to the object side with locus of a convex to the object side, and the fifth lens unit G 5  does not move. That is, in zooming, the second lens unit G 2 , the third lens unit G 3 , and the fourth lens unit G 4  individually move along the optical axis so that the interval between the first lens unit G 1  and the second lens unit G 2  increases, the interval between the second lens unit G 2  and the third lens unit G 3  decreases, and the interval between the fourth lens unit G 4  and the fifth lens unit G 5  increases. 
     In focusing from an infinity in-focus condition to a close-object in-focus condition, the fourth lens unit G 4  moves to the image side along the optical axis. 
     The tenth lens element L 10  and the eleventh lens element L 11  which are components of the third lens unit G 3  correspond to an image blur compensating lens unit described later. By moving the tenth lens element L 10  and the eleventh lens element L 11  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated, that is, image blur caused by hand blur, vibration, and the like can be compensated optically. 
     Embodiment 2 
     As shown in  FIG. 4 , the first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; and a positive meniscus second lens element L 2  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. The second lens element L 2  has an aspheric image side surface. 
     The second lens unit G 2 , in order from the object side to the image side, comprises: a negative meniscus third lens element L 3  with the convex surface facing the object side; a bi-concave fourth lens element L 4 ; and a bi-convex fifth lens element L 5 . The third lens element L 3  is a hybrid lens element comprising: a lens element formed of a glass material; and a bi-concave transparent resin layer which is formed of an ultraviolet curable resin and is cemented to an object side surface of the lens element. The third lens element L 3  has an aspheric object side surface. 
     The third lens unit G 3  comprises solely a positive meniscus sixth lens element L 6  with the convex surface facing the object side. 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a bi-convex seventh lens element L 7 ; a bi-convex eighth lens element L 8 ; a bi-concave ninth lens element L 9 ; and a bi-convex tenth lens element L 10 . Among these, the eighth lens element L 8  and the ninth lens element L 9  are cemented with each other. The seventh lens element L 7  has two aspheric surfaces. The tenth lens element L 10  has two aspheric surfaces. 
     The fifth lens unit G 5 , in order from the object side to the image side, comprises: a positive meniscus eleventh lens element L 11  with the convex surface facing the image side; and a bi-concave twelfth lens element L 12 . The eleventh lens element L 11  and the twelfth lens element L 12  are cemented with each other. The twelfth lens element L 12  has an aspheric image side surface. 
     The sixth lens unit G 6  comprises solely a bi-convex thirteenth lens element L 13 . The thirteenth lens element L 13  has two aspheric surfaces. 
     In zooming from a wide-angle limit to a telephoto limit at the time of image taking, the first lens unit G 1  does not move, the second lens unit G 2  moves to the image side, the aperture diaphragm A does not move, the third lens unit G 3  does not move, the fourth lens unit G 4  moves to the object side, the fifth lens unit G 5  moves to the object side with locus of a convex to the object side, and the sixth lens unit G 6  does not move. That is, in zooming, the second lens unit G 2 , the fourth lens unit G 4 , and the fifth lens unit G 5  individually move along the optical axis so that the interval between the first lens unit G 1  and the second lens unit G 2  increases, the interval between the second lens unit G 2  and the third lens unit G 3  decreases, the interval between the third lens unit G 3  and the fourth lens unit G 4  decreases, and the interval between the fifth lens unit G 5  and the sixth lens unit G 6  increases. 
     In focusing from an infinity in-focus condition to a close-object in-focus condition, the fifth lens unit G 5  moves to the image side along the optical axis. 
     The tenth lens element L 10  which is a component of the fourth lens unit G 4  corresponds to an image blur compensating lens unit described later. By moving the tenth lens element L 10  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated, that is, image blur caused by hand blur, vibration, and the like can be compensated optically. 
     Embodiment 3 
     As shown in  FIG. 7 , the first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; and a bi-convex second lens element L 2 . The first lens element L 1  and the second lens element L 2  are cemented with each other. The second lens element L 2  is a hybrid lens element comprising: a lens element formed of a glass material; and a positive meniscus transparent resin layer with the convex surface facing the image side, which is formed of an ultraviolet curable resin and is cemented to an image side surface of the lens element. The second lens element L 2  has an aspheric image side surface. 
     The second lens unit G 2 , in order from the object side to the image side, comprises: a bi-concave third lens element L 3 ; a bi-concave fourth lens element L 4 ; and a bi-convex fifth lens element L 5 . The third lens element L 3  is a hybrid lens element comprising: a lens element formed of a glass material; and a negative meniscus transparent resin layer with the convex surface facing the image side, which is formed of an ultraviolet curable resin and is cemented to an object side surface of the lens element. The third lens element L 3  has an aspheric object side surface. 
     The third lens unit G 3  comprises solely a bi-convex sixth lens element L 6 . 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a bi-convex seventh lens element L 7 ; a bi-convex eighth lens element L 8 ; a bi-concave ninth lens element L 9 ; a bi-convex tenth lens element L 10 ; and a negative meniscus eleventh lens element L 11  with the convex surface facing the image side. Among these, the eighth lens element L 8  and the ninth lens element L 9  are cemented with each other, and the tenth lens element L 10  and the eleventh lens element L 11  are cemented with each other. The seventh lens element L 7  has two aspheric surfaces. The tenth lens element L 10  has an aspheric object side surface. 
     The fifth lens unit G 5 , in order from the object side to the image side, comprises: a bi-convex twelfth lens element L 12 ; and a bi-concave thirteenth lens element L 13 . The twelfth lens element L 12  and the thirteenth lens element L 13  are cemented with each other. The thirteenth lens element L 13  has an aspheric image side surface. 
     The sixth lens unit G 6 , in order from the object side to the image side, comprises: a bi-convex fourteenth lens element L 14 ; and a negative meniscus fifteenth lens element L 15  with the convex surface facing the image side. The fourteenth lens element L 14  and the fifteenth lens element L 15  are cemented with each other. The fourteenth lens element L 14  has an aspheric object side surface. 
     In zooming from a wide-angle limit to a telephoto limit at the time of image taking, the first lens unit G 1  does not move, the second lens unit G 2  moves to the image side, the aperture diaphragm A does not move, the third lens unit G 3  does not move, the fourth lens unit G 4  moves to the object side, the fifth lens unit G 5  moves to the object side with locus of a convex to the object side, and the sixth lens unit G 6  does not move. That is, in zooming, the second lens unit G 2 , the fourth lens unit G 4 , and the fifth lens unit G 5  individually move along the optical axis so that the interval between the first lens unit G 1  and the second lens unit G 2  increases, the interval between the second lens unit G 2  and the third lens unit G 3  decreases, the interval between the third lens unit G 3  and the fourth lens unit G 4  decreases, and the interval between the fifth lens unit G 5  and the sixth lens unit G 6  increases. 
     In focusing from an infinity in-focus condition to a close-object in-focus condition, the fifth lens unit G 5  moves to the image side along the optical axis. 
     The tenth lens element L 10  and the eleventh lens element L 11  which are components of the fourth lens unit G 4  correspond to an image blur compensating lens unit described later. By moving the tenth lens element L 10  and the eleventh lens element L 11  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated, that is, image blur caused by hand blur, vibration, and the like can be compensated optically. 
     Embodiment 4 
     As shown in  FIG. 10 , the first lens unit G 1  comprises solely a bi-convex first lens element L 1 . The first lens element L 1  has an aspheric image side surface. 
     The second lens unit G 2 , in order from the object side to the image side, comprises: a negative meniscus second lens element L 2  with the convex surface facing the object side; a bi-concave third lens element L 3 ; and a bi-convex fourth lens element L 4 . The second lens element L 2  is a hybrid lens element comprising: a lens element formed of a glass material; and a bi-concave transparent resin layer which is formed of an ultraviolet curable resin and is cemented to an object side surface of the lens element. The second lens element L 2  has an aspheric object side surface. 
     The third lens unit G 3  comprises solely a positive meniscus fifth lens element L 5  with the convex surface facing the object side. 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a bi-convex sixth lens element L 6 ; a bi-convex seventh lens element L 7 ; a bi-concave eighth lens element L 8 ; and a bi-convex ninth lens element L 9 . Among these, the seventh lens element L 7  and the eighth lens element L 8  are cemented with each other. The sixth lens element L 6  has two aspheric surfaces. The ninth lens element L 9  has two aspheric surfaces. 
     The fifth lens unit G 5 , in order from the object side to the image side, comprises: a positive meniscus tenth lens element L 10  with the convex surface facing the image side; and a bi-concave eleventh lens element L 11 . The tenth lens element L 10  and the eleventh lens element L 11  are cemented with each other. The eleventh lens element L 11  has an aspheric image side surface. 
     The sixth lens unit G 6  comprises solely a bi-convex twelfth lens element L 12 . The twelfth lens element L 12  has two aspheric surfaces. 
     In zooming from a wide-angle limit to a telephoto limit at the time of image taking, the first lens unit G 1  does not move, the second lens unit G 2  moves to the image side, the aperture diaphragm A does not move, the third lens unit G 3  does not move, the fourth lens unit G 4  moves to the object side, the fifth lens unit G 5  moves to the object side with locus of a convex to the object side, and the sixth lens unit G 6  does not move. That is, in zooming, the second lens unit G 2 , the fourth lens unit G 4 , and the fifth lens unit G 5  individually move along the optical axis so that the interval between the first lens unit G 1  and the second lens unit G 2  increases, the interval between the second lens unit G 2  and the third lens unit G 3  decreases, the interval between the third lens unit G 3  and the fourth lens unit G 4  decreases, and the interval between the fifth lens unit G 5  and the sixth lens unit G 6  increases. 
     In focusing from an infinity in-focus condition to a close-object in-focus condition, the fifth lens unit G 5  moves to the image side along the optical axis. 
     The ninth lens element L 9  which is a component of the fourth lens unit G 4  corresponds to an image blur compensating lens unit described later. By moving the ninth lens element L 9  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated, that is, image blur caused by hand blur, vibration, and the like can be compensated optically. 
     Embodiment 5 
     As shown in  FIG. 13 , the first lens unit G 1 , in order from the object side to the image side, comprises: a negative meniscus first lens element L 1  with the convex surface facing the object side; and a positive meniscus second lens element L 2  with the convex surface facing the object side. The first lens element L 1  and the second lens element L 2  are cemented with each other. The second lens element L 2  has an aspheric image side surface. 
     The second lens unit G 2 , in order from the object side to the image side, comprises: a negative meniscus third lens element L 3  with the convex surface facing the object side; a bi-concave fourth lens element L 4 ; and a bi-convex fifth lens element L 5 . The third lens element L 3  is a hybrid lens element comprising: a lens element formed of a glass material; and a bi-concave transparent resin layer which is formed of an ultraviolet curable resin and is cemented to an object side surface of the lens element. The third lens element L 3  has an aspheric object side surface. 
     The third lens unit G 3  comprises solely a negative meniscus sixth lens element L 6  with the convex surface facing the object side. 
     The fourth lens unit G 4 , in order from the object side to the image side, comprises: a bi-convex seventh lens element L 7 ; a bi-convex eighth lens element L 8 ; a bi-concave ninth lens element L 9 ; and a bi-convex tenth lens element L 10 . Among these, the eighth lens element L 8  and the ninth lens element L 9  are cemented with each other. The seventh lens element L 7  has two aspheric surfaces. The tenth lens element L 10  has two aspheric surfaces. 
     The fifth lens unit G 5 , in order from the object side to the image side, comprises: a bi-convex eleventh lens element L 11 ; and a bi-concave twelfth lens element L 12 . The eleventh lens element L 11  and the twelfth lens element L 12  are cemented with each other. The twelfth lens element L 12  has an aspheric image side surface. 
     The sixth lens unit G 6  comprises solely a bi-convex thirteenth lens element L 13 . The thirteenth lens element L 13  has two aspheric surfaces. 
     In zooming from a wide-angle limit to a telephoto limit at the time of image taking, the first lens unit G 1  does not move, the second lens unit G 2  moves to the image side, the aperture diaphragm A does not move, the third lens unit G 3  does not move, the fourth lens unit G 4  moves to the object side, the fifth lens unit G 5  moves to the object side, and the sixth lens unit G 6  does not move. That is, in zooming, the second lens unit G 2 , the fourth lens unit G 4 , and the fifth lens unit G 5  individually move along the optical axis so that the interval between the first lens unit G 1  and the second lens unit G 2  increases, the interval between the second lens unit G 2  and the third lens unit G 3  decreases, the interval between the third lens unit G 3  and the fourth lens unit G 4  decreases, and the interval between the fifth lens unit G 5  and the sixth lens unit G 6  increases. 
     In focusing from an infinity in-focus condition to a close-object in-focus condition, the fifth lens unit G 5  moves to the image side along the optical axis. 
     The tenth lens element L 10  which is a component of the fourth lens unit G 4  corresponds to an image blur compensating lens unit described later. By moving the tenth lens element L 10  in a direction perpendicular to the optical axis, image point movement caused by vibration of the entire system can be compensated, that is, image blur caused by hand blur, vibration, and the like can be compensated optically. 
     As described above, Embodiments 1 to 5 have been described as examples of art disclosed in the present application. However, the art in the present disclosure is not limited to these embodiments. It is understood that various modifications, replacements, additions, omissions, and the like have been performed in these embodiments to give optional embodiments, and the art in the present disclosure can be applied to the optional embodiments. 
     The following description is given for conditions that a zoom lens system like the zoom lens systems according to Embodiments 1 to 5 can satisfy. Here, a plurality of beneficial conditions is set forth for the zoom lens system according to each embodiment. A construction that satisfies all the plurality of conditions is most effective for the zoom lens system. However, when an individual condition is satisfied, a zoom lens system having the corresponding effect is obtained. 
     For example, in a zoom lens system like the zoom lens systems according to Embodiments 1 to 5, having a plurality of lens units, each lens unit being composed of at least one lens element, and in order from an object side to an image side, comprising: a first lens unit having positive optical power; and a second lens unit having negative optical power, in which the first lens unit is composed of two or less lens elements, and in zooming from a wide-angle limit to a telephoto limit at the time of image taking, at least the first lens unit is fixed with respect to an image surface (this lens configuration is referred to as a basic configuration of the embodiments, hereinafter), the following conditions (1) and (2) are satisfied. 
         L   T   /f   T &lt;1.45  (1)
 
       2.6&lt;( f   T   /f   W )×(tan(θ W )) 2   (2)
 
     where, 
     L T  is an overall length of lens system at a telephoto limit (a distance from a most object side surface of the first lens unit to the image surface, at a telephoto limit), 
     f T  is a focal length of the entire system at the telephoto limit, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     θ W  is a half view angle (°) at the wide-angle limit. 
     The condition (1) sets forth the relationship between the overall length of lens system at the telephoto limit, and the focal length of the entire system at the telephoto limit. When the value exceeds the upper limit of the condition (1), the overall length of lens system at the telephoto limit becomes excessively long, which makes it difficult to compensate fluctuation in astigmatism associated with zooming. 
     When the following condition (1)′ is satisfied, the above-mentioned effect is achieved more successfully. 
         L   T   /f   T &lt;1.25  (1)′
 
     The condition (2) sets forth the relationship among the focal length of the entire system at the telephoto limit, the focal length of the entire system at the wide-angle limit, and the half view angle at the wide-angle limit. When the value goes below the lower limit of the condition (2), the half view angle at the wide-angle limit becomes excessively small, which results in an insufficient imaging range at the wide-angle limit. Further, it becomes difficult to compensate magnification chromatic aberration at the telephoto limit. 
     When the following condition (2)′ is satisfied, the above-mentioned effect is achieved more successfully. 
       5.2&lt;( f   T   /F   W )×(tan(θ W )) 2   (2)′
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (3). 
       0.5 &lt;F   W   /T   1G &lt;3.0  (3)
 
     where, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     T 1G  is an optical axial thickness of the first lens unit. 
     The condition (3) sets forth the relationship between the focal length of the entire system at the wide-angle limit, and the optical axial thickness of the first lens unit. When the value goes below the lower limit of the condition (3), the optical axial thickness of the first lens unit becomes excessively large, which makes it difficult to compensate astigmatism at the wide-angle limit. When the value exceeds the upper limit of the condition (3), the optical axial thickness of the first lens unit becomes excessively small, which makes it difficult to compensate magnification chromatic aberration at the telephoto limit. 
     When at least one of the following conditions (3)′ and (3)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       0.8 &lt;f   W   /T   1G   (3)′
 
         F   W   /T   1G &lt;2.0  (3)″
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (4). 
       0.4 &lt;Y   T   /T   1G &lt;3.0  (4)
 
     where, 
     Y T  is an image height at a telephoto limit, and 
     T 1G  is an optical axial thickness of the first lens unit. 
     The condition (4) sets forth the relationship between the image height at the telephoto limit, and the optical axial thickness of the first lens unit. When the value goes below the lower limit of the condition (4), the optical axial thickness of the first lens unit becomes excessively large, which makes it difficult to compensate astigmatism at the wide-angle limit. When the value exceeds the upper limit of the condition (4), the optical axial thickness of the first lens unit becomes excessively small, which makes it difficult to compensate magnification chromatic aberration at the telephoto limit. 
     When at least one of the following conditions (4)′ and (4)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       0.7 &lt;Y   T   /T   1G   (4)′
 
         Y   T   /T   1G &lt;1.8  (4)″
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (5). 
       0.3 &lt;f   W   /T   imgG &lt;7.0  (5)
 
     where, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     T imgG  is an optical axial thickness of a lens unit located closest to the image side in the entire system. 
     The condition (5) sets forth the relationship between the focal length of the entire system at the wide-angle limit, and the optical axial thickness of the lens unit located closest to the image side in the entire system. When the value goes below the lower limit of the condition (5), the optical axial thickness of the lens unit located closest to the image side becomes excessively large relative to the focal length of the entire system at the wide-angle limit, which makes it difficult to compensate astigmatism at the wide-angle limit. Further, it becomes difficult to provide a compact lens barrel, interchangeable lens apparatus, or camera system. When the value exceeds the upper limit of the condition (5), the optical axial thickness of the lens unit located closest to the image side becomes excessively small, which makes it difficult to compensate astigmatism at the telephoto limit. 
     When at least one of the following conditions (5)′ and (5)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       1.0 &lt;f   W   /T   imgG   (5)′
 
         f   W   /T   imgG &lt;5.0  (5)″
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (6). 
       0.2 &lt;Y   T   /T   imgG &lt;6.0  (6)
 
     where, 
     Y T  is an image height at a telephoto limit, and 
     T imgG  is an optical axial thickness of a lens unit located closest to the image side in the entire system. 
     The condition (6) sets forth the relationship between the image height at the telephoto limit, and the optical axial thickness of the lens unit located closest to the image side in the entire system. When the value goes below the lower limit of the condition (6), the optical axial thickness of the lens unit located closest to the image side becomes excessively large, which makes it difficult to compensate astigmatism at the wide-angle limit. Further, it becomes difficult to provide a compact lens barrel, interchangeable lens apparatus, or camera system. When the value exceeds the upper limit of the condition (6), the optical axial thickness of the lens unit located closest to the image side becomes excessively small, which makes it difficult to compensate astigmatism at the telephoto limit. 
     When at least one of the following conditions (6)′ and (6)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       1.2 &lt;Y   T   /T   imgG   (6)′
 
         Y   T   /T   imgG &lt;3.0  (6)″
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (7). 
       4.0&lt; f   W   /T   air1G2Gw &lt;350.0  (7)
 
     where, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     T air1G2GW  is an air space between the first lens unit and the second lens unit at the wide-angle limit. 
     The condition (7) sets forth the relationship between the focal length of the entire system at the wide-angle limit, and the air space between the first lens unit and the second lens unit at the wide-angle limit. When the value goes below the lower limit of the condition (7), the air space between the first lens unit and the second lens unit at the wide-angle limit becomes excessively large, which makes it difficult to compensate curvature of field at the wide-angle limit. When the value exceeds the upper limit of the condition (7), the focal length of the entire system at the wide-angle limit becomes excessively long, which results in an insufficient imaging range at the wide-angle limit. Further, it becomes difficult to provide a compact lens barrel, interchangeable lens apparatus, or camera system. 
     When at least one of the following conditions (7)′ and (7)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       15.0 &lt;f   W   /T   air1G2GW   (7)′
 
         f   W   /T   air1G2GW &lt;20.0  (7)′
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (8). 
         nd   1G &lt;1.82  (8)
 
     where, 
     nd 1G  is a refractive index to the d-line of a lens element having the largest optical axial thickness among the lens elements constituting the first lens unit. 
     The condition (8) sets forth the refractive index to the d-line of the lens element having the largest optical axial thickness among the lens elements constituting the first lens unit. When the value exceeds the upper limit of the condition (8), it becomes difficult to compensate magnification chromatic aberration at the telephoto limit. 
     When the following condition (8)′ is satisfied, the above-mentioned effect is achieved more successfully. 
         nd   1G &lt;1.65  (8)′
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (9). 
       48 &lt;vd   1G   (9)
 
     where, 
     vd 1G  is an Abbe number to the d-line of a lens element having the largest optical axial thickness among the lens elements constituting the first lens unit. 
     The condition (9) sets forth the Abbe number to the d-line of the lens element having the largest optical axial thickness among the lens elements constituting the first lens unit. When the value goes below the lower limit of the condition (9), it becomes difficult to compensate magnification chromatic aberration at the telephoto limit. 
     When the following condition (9)′ is satisfied, the above-mentioned effect is achieved more successfully. 
       60 &lt;vd   1G   (9)′
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (10). 
       1.0 &lt;|M   2G   /f   W |&lt;5.0  (10)
 
     where, 
     M 2G  is an amount of movement of the second lens unit with respect to the image surface, in zooming from a wide-angle limit to a telephoto limit at the time of image taking, and 
     f W  is a focal length of the entire system at the wide-angle limit. 
     The condition (10) sets forth the relationship between the amount of movement of the second lens unit in zooming, and the focal length of the entire system at the wide-angle limit. When the value goes below the lower limit of the condition (10), contribution of the second lens unit to magnification change becomes excessively small, which makes it difficult to compensate astigmatism at the wide-angle limit. When the value exceeds the upper limit of the condition (10), the optical power of the second lens unit becomes excessively strong, which makes it difficult to compensate distortion at the wide-angle limit. 
     When at least one of the following conditions (10)′ and (10)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       1.5 &lt;|M   2G   /f   W|   (10)′
 
       | M   2G   /f   W |&lt;3.0  (10)″
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (11). 
       1.2 &lt;|M   2G   /Y   T |&lt;4.5  (11)
 
     where, 
     M 2G  is an amount of movement of the second lens unit with respect to the image surface, in zooming from a wide-angle limit to a telephoto limit at the time of image taking, and 
     Y T  is an image height at the telephoto limit. 
     The condition (11) sets forth the relationship between the amount of movement of the second lens unit in zooming, and the image height at the telephoto limit. When the value goes below the lower limit of the condition (11), contribution of the second lens unit to magnification change becomes excessively small, which makes it difficult to compensate astigmatism at the wide-angle limit. When the value exceeds the upper limit of the condition (11), the optical power of the second lens unit becomes excessively strong, which makes it difficult to compensate distortion at the wide-angle limit. 
     When at least one of the following conditions (11)′ and (11)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       2.0 &lt;|M   2G   /Y   T |  (11)′
 
       | M   2G   /Y   T |&lt;3.3  (11)″
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (12). 
       0.5 &lt;f   W   /T   2G &lt;3.0  (12)
 
     where, 
     f W  is a focal length of the entire system at a wide-angle limit, and 
     T 2G  is an optical axial thickness of the second lens unit. 
     The condition (12) sets forth the relationship between the focal length of the entire system at the wide-angle limit, and the optical axial thickness of the second lens unit. When the value goes below the lower limit of the condition (12), the optical axial thickness of the second lens unit becomes excessively large, which makes it difficult to compensate astigmatism at the wide-angle limit. When the value exceeds the upper limit of the condition (12), the optical axial thickness of the second lens unit becomes excessively small, which makes it difficult to compensate astigmatism at the telephoto limit. 
     When at least one of the following conditions (12)′ and (12)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       0.7 &lt;f   W   /T   2G   (12)′
 
         f   W   /T   2G &lt;1.5  (12)″
 
     It is beneficial that a zoom lens system having the basic configuration like the zoom lens systems according to Embodiments 1 to 5 satisfies the following condition (13). 
       4.0 &lt;f   T   /T   2G &lt;21.0  (13)
 
     where, 
     f T  is a focal length of the entire system at a telephoto limit, and 
     T 2G  is an optical axial thickness of the second lens unit. 
     The condition (13) sets forth the relationship between the focal length of the entire system at the telephoto limit, and the optical axial thickness of the second lens unit. When the value goes below the lower limit of the condition (13), the optical axial thickness of the second lens unit becomes excessively large, which makes it difficult to compensate astigmatism at the wide-angle limit. When the value exceeds the upper limit of the condition (13), the optical axial thickness of the second lens unit becomes excessively small, which makes it difficult to compensate astigmatism at the telephoto limit. 
     When at least one of the following conditions (13)′ and (13)″ is satisfied, the above-mentioned effect is achieved more successfully. 
       5.0 &lt;f   T   /T   2G   (13)′
 
         f   T   /T   2G &lt;11.0  (13)″
 
     It is beneficial for a zoom lens system to be provided with an image blur compensating lens unit which moves in a direction perpendicular to the optical axis in order to optically compensate image blur, like the zoom lens systems according to Embodiments 1 to 5. By virtue of the image blur compensating lens unit, image point movement caused by vibration of the entire system can be compensated. 
     When compensating image point movement caused by vibration of the entire system, the image blur compensating lens unit moves in the direction perpendicular to the optical axis, so that image blur is compensated in a state that size increase in the entire zoom lens system is suppressed to realize a compact construction and that excellent imaging characteristics such as small decentering coma aberration and small decentering astigmatism are satisfied. 
     It is beneficial that the image blur compensating lens unit moves with respect to the image surface, in zooming from a wide-angle limit to a telephoto limit at the time of image taking. When the image blur compensating lens unit does not move in zooming, the amount of movement of the image blur compensating lens unit in the direction perpendicular to the optical axis increases, which makes it difficult to compensate partial blur in the image blur compensation state. Further, the configuration of the drive mechanism for the image blur compensating lens unit is enlarged, which makes it difficult to provide a compact lens barrel, interchangeable lens apparatus, or camera system. 
     Further, it is beneficial that the image blur compensating lens unit is a part of any one of the lens units constituting the lens system. When the image blur compensating lens unit is the entirety of any one of the lens units constituting the lens system, the configuration of the drive mechanism for the image blur compensating lens unit is enlarged, which makes it difficult to provide a compact lens barrel, interchangeable lens apparatus, or camera system. The “part” of a lens unit may be a single lens element, or a plurality of lens elements adjacent to each other. 
     It is beneficial that the aperture diaphragm is fixed with respect to the image surface in zooming from a wide-angle limit to a telephoto limit at the time of image taking, like the zoom lens systems according to Embodiments 1 to 5. When the aperture diaphragm moves in zooming, it is difficult to secure an amount of peripheral light at the wide-angle limit. Further, it becomes difficult to provide a compact lens barrel, interchangeable lens apparatus, or camera system. 
     It is beneficial that the lens unit located closest to the image size in the entire system is fixed with respect to the image surface in zooming from a wide-angle limit to a telephoto limit at the time of image taking, like the zoom lens systems according to Embodiments 1 to 5. When the lens unit located closest to the image side moves in zooming, it becomes difficult to compensate astigmatism at the telephoto limit. 
     It is beneficial that in zooming from a wide-angle limit to a telephoto limit at the time of image taking, the number of an aperture diaphragm and lens units, that are fixed with respect to the image surface, is equal to the number of lens units that move with respect to the image surface, like the zoom lens system according to Embodiment 1, or the number of lens units that are fixed with respect to the image surface is equal to the number of lens units that move with respect to the image surface, like the zoom lens systems according to Embodiments 2 to 5. When the number of fixed aperture diaphragm and fixed lens units is different from the number of moving lens units, or when the number of fixed lens units is different from the number of moving lens units, it becomes difficult to compensate fluctuation in spherical aberration associated with zooming. Further, a problem occurs in designing a lens barrel, which makes it difficult to provide a compact lens barrel, interchangeable lens apparatus, or camera system. 
     It is beneficial that the first lens unit includes an aspheric surface, like the zoom lens systems according to Embodiments 1 to 5. When the first lens unit includes no aspheric surfaces, it becomes difficult to compensate astigmatism at the wide-angle limit. 
     Each of the lens units constituting the zoom lens system according to any of Embodiments 1 to 5 is composed exclusively of refractive type lens elements that deflect the incident light by refraction (that is, lens elements of a type in which deflection is achieved at the interface between media each having a distinct refractive index). However, the present invention is not limited to this. For example, the lens units may employ diffractive type lens elements that deflect the incident light by diffraction; refractive-diffractive hybrid type lens elements that deflect the incident light by a combination of diffraction and refraction; or gradient index type lens elements that deflect the incident light by distribution of refractive index in the medium. In particular, in refractive-diffractive hybrid type lens elements, when a diffraction structure is formed in the interface between media having mutually different refractive indices, wavelength dependence in the diffraction efficiency is improved. Thus, such a configuration is beneficial. 
     Embodiment 6 
       FIG. 16  is a schematic construction diagram of an interchangeable-lens type digital camera system according to Embodiment 6. 
     The interchangeable-lens type digital camera system  100  according to Embodiment 6 includes a camera body  101 , and an interchangeable lens apparatus  201  which is detachably connected to the camera body  101 . 
     The camera body  101  includes: an image sensor  102  which receives an optical image formed by a zoom lens system  202  of the interchangeable lens apparatus  201 , and converts the optical image into an electric image signal; a liquid crystal monitor  103  which displays the image signal obtained by the image sensor  102 ; and a camera mount section  104 . On the other hand, the interchangeable lens apparatus  201  includes: a zoom lens system  202  according to any of Embodiments 1 to 5; a lens barrel  203  which holds the zoom lens system  202 ; and a lens mount section  204  connected to the camera mount section  104  of the camera body  101 . The camera mount section  104  and the lens mount section  204  are physically connected to each other. Moreover, the camera mount section  104  and the lens mount section  204  function as interfaces which allow the camera body  101  and the interchangeable lens apparatus  201  to exchange signals, by electrically connecting a controller (not shown) in the camera body  101  and a controller (not shown) in the interchangeable lens apparatus  201 . In  FIG. 16 , the zoom lens system according to Embodiment 1 is employed as the zoom lens system  202 . 
     In Embodiment 6, since the zoom lens system  202  according to any of Embodiments 1 to 5 is employed, a compact interchangeable lens apparatus having excellent imaging performance can be realized at low cost. Moreover, size reduction and cost reduction of the entire camera system  100  according to Embodiment 6 can be achieved. In the zoom lens systems according to Embodiments 1 to 5, the entire zooming range need not be used. That is, in accordance with a desired zooming range, a range where satisfactory optical performance is obtained may exclusively be used. Then, the zoom lens system may be used as one having a lower magnification than the zoom lens systems described in Embodiments 1 to 5. 
     As described above, Embodiment 6 has been described as an example of art disclosed in the present application. However, the art in the present disclosure is not limited to this embodiment. It is understood that various modifications, replacements, additions, omissions, and the like have been performed in this embodiment to give optional embodiments, and the art in the present disclosure can be applied to the optional embodiments. 
     The following description is given for numerical examples in which the zoom lens system according to Embodiments 1 to 5 are implemented practically. In the numerical examples, the units of the length in the tables are all “mm”, while the units of the view angle are all “°”. Moreover, in the numerical examples, r is the radius of curvature, d is the axial distance, nd is the refractive index to the d-line, and vd is the Abbe number to the d-line. In the numerical examples, the surfaces marked with * are aspheric surfaces, and the aspheric surface configuration is defined by the following expression. 
     
       
         
           
             Z 
             = 
             
               
                 
                   
                     h 
                     2 
                   
                   / 
                   r 
                 
                 
                   1 
                   + 
                   
                     
                       1 
                       - 
                       
                         
                           ( 
                           
                             1 
                             + 
                             κ 
                           
                           ) 
                         
                          
                         
                           
                             ( 
                             
                               h 
                               / 
                               r 
                             
                             ) 
                           
                           2 
                         
                       
                     
                   
                 
               
               + 
               
                 ∑ 
                 
                   
                     A 
                     n 
                   
                    
                   
                     h 
                     n 
                   
                 
               
             
           
         
       
     
     Here, the symbols in the formula indicate the following quantities. 
     Z is a distance from a point on an aspherical surface at a height h relative to the optical axis to a tangential plane at the vertex of the aspherical surface, 
     h is a height relative to the optical axis, 
     r is a radius of curvature at the top, 
     κ is a conic constant, and 
     A n  is a n-th order aspherical coefficient. 
       FIGS. 2 ,  5 ,  8 ,  11 , and  14  are longitudinal aberration diagrams of an infinity in-focus condition of the zoom lens systems according to Numerical Examples 1 to 5, respectively. 
     In each longitudinal aberration diagram, part (a) shows the aberration at a wide-angle limit, part (b) shows the aberration at a middle position, and part (c) shows the aberration at a telephoto limit. Each longitudinal aberration diagram, in order from the left-hand side, shows the spherical aberration (SA (mm)), the astigmatism (AST (mm)) and the distortion (DIS (%)). In each spherical aberration diagram, the vertical axis indicates the F-number (in each Fig., indicated as F), and the solid line, the short dash line and the long dash line indicate the characteristics to the d-line, the F-line and the C-line, respectively. In each astigmatism diagram, the vertical axis indicates the image height (in each Fig., indicated as H), and the solid line and the dash line indicate the characteristics to the sagittal plane (in each Fig., indicated as “s”) and the meridional plane (in each Fig., indicated as “m”), respectively. In each distortion diagram, the vertical axis indicates the image height (in each Fig., indicated as H). 
       FIGS. 3 ,  6 ,  9 ,  12 , and  15  are lateral aberration diagrams of the zoom lens systems at a telephoto limit according to Numerical Examples 1 to 5, respectively. 
     In each lateral aberration diagram, the aberration diagrams in the upper three parts correspond to a basic state where image blur compensation is not performed at a telephoto limit, while the aberration diagrams in the lower three parts correspond to an image blur compensation state where the image blur compensating lens unit is moved by a predetermined amount in a direction perpendicular to the optical axis at a telephoto limit. Among the lateral aberration diagrams of a basic state, the upper part shows the lateral aberration at an image point of 70% of the maximum image height, the middle part shows the lateral aberration at the axial image point, and the lower part shows the lateral aberration at an image point of −70% of the maximum image height. Among the lateral aberration diagrams of an image blur compensation state, the upper part shows the lateral aberration at an image point of 70% of the maximum image height, the middle part shows the lateral aberration at the axial image point, and the lower part shows the lateral aberration at an image point of −70% of the maximum image height. In each lateral aberration diagram, the horizontal axis indicates the distance from the principal ray on the pupil surface, and the solid line, the short dash line and the long dash line indicate the characteristics to the d-line, the F-line and the C-line, respectively. In each lateral aberration diagram, the meridional plane is adopted as the plane containing the optical axis of the first lens unit G 1  and the optical axis of the third lens unit G 3  (Numerical Example 1), or as the plane containing the optical axis of the first lens unit G 1  and the optical axis of the fourth lens unit G 4  (Numerical Examples 2 to 5). 
     Here, in the zoom lens system according to each numerical example, the amount of movement of the image blur compensating lens unit in a direction perpendicular to the optical axis in an image blur compensation state at a telephoto limit is as follows. 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Numerical Example 
                 Amount of movement (mm) 
               
               
                   
                   
               
             
            
               
                   
                 1 
                 0.249 
               
               
                   
                 2 
                 0.280 
               
               
                   
                 3 
                 0.375 
               
               
                   
                 4 
                 0.183 
               
               
                   
                 5 
                 0.276 
               
               
                   
                   
               
            
           
         
       
     
     Here, when the shooting distance is infinity, at a telephoto limit, the amount of image decentering in a case that the zoom lens system inclines by 0.5° is equal to the amount of image decentering in a case that the image blur compensating lens unit displaces in parallel by each of the above-mentioned values in a direction perpendicular to the optical axis. 
     As seen from the lateral aberration diagrams, satisfactory symmetry is obtained in the lateral aberration at the axial image point. Further, when the lateral aberration at the +70% image point and the lateral aberration at the −70% image point are compared with each other in the basic state, all have a small degree of curvature and almost the same inclination in the aberration curve. Thus, decentering coma aberration and decentering astigmatism are small. This indicates that sufficient imaging performance is obtained even in the image blur compensation state. Further, when the image blur compensation angle of a zoom lens system is the same, the amount of parallel translation required for image blur compensation decreases with decreasing focal length of the entire zoom lens system. Thus, at arbitrary zoom positions, sufficient image blur compensation can be performed for image blur compensation angles up to at least 0.5° without degrading the imaging characteristics. 
     Numerical Example 1 
     The zoom lens system of Numerical Example 1 corresponds to Embodiment 1 shown in  FIG. 1 . Table 1 shows the surface data of the zoom lens system of Numerical Example 1. Table 2 shows the aspherical data. Table 3 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 38.26700 
                 1.50000 
                 1.94391 
                 25.2 
               
               
                  2 
                 30.74450 
                 10.48520  
                 1.55332 
                 71.7 
               
               
                  3* 
                 −356.27340 
                 Variable 
               
               
                  4* 
                 −169.44210 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  5 
                 −649.98740 
                 1.00000 
                 1.91082 
                 35.2 
               
               
                  6 
                 14.10850 
                 7.35240 
               
               
                  7 
                 −32.03880 
                 0.60000 
                 1.91082 
                 35.2 
               
               
                  8 
                 124.13720 
                 0.20000 
               
               
                  9 
                 43.98420 
                 5.06110 
                 1.94595 
                 18.0 
               
               
                 10 
                 −47.05720 
                 0.55000 
                 1.91082 
                 35.2 
               
               
                 11 
                 −105.08590 
                 Variable 
               
               
                 12 
                 ∞ 
                 Variable 
               
               
                 (Diaphragm) 
               
               
                 13 
                 13.13340 
                 4.29530 
                 1.54757 
                 46.2 
               
               
                 14 
                 −36.48530 
                 0.20000 
               
               
                  15* 
                 28.50810 
                 2.22860 
                 1.58313 
                 59.5 
               
               
                 16 
                 −33.94420 
                 0.55000 
                 1.91082 
                 35.2 
               
               
                 17 
                 16.10430 
                 3.93280 
               
               
                  18* 
                 17.55000 
                 6.16360 
                 1.58913 
                 61.3 
               
               
                 19 
                 −10.06250 
                 0.50000 
                 1.84666 
                 23.8 
               
               
                 20 
                 −15.67220 
                 Variable 
               
               
                 21 
                 −49.38110 
                 2.59760 
                 1.99537 
                 20.6 
               
               
                 22 
                 −11.02690 
                 0.80000 
                 1.88202 
                 37.2 
               
               
                  23* 
                 11.67600 
                 Variable 
               
               
                  24* 
                 41.86890 
                 7.23900 
                 1.58913 
                 61.3 
               
               
                 25 
                 −19.12900 
                 0.70000 
                 1.98162 
                 29.5 
               
               
                 26 
                 −29.28990 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 (Aspherical data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 Surface No. 3 
               
               
                 K = 0.00000E+00, A4 = 1.38459E−06, A6 = −7.07527E−10, A8 = 8.06553E−13 
               
               
                 A10 = −5.96314E−16 
               
               
                 Surface No. 4 
               
               
                 K = 0.00000E+00, A4 = 2.11825E−05, A6 = −1.09394E−07, A8 = 5.35730E−10 
               
               
                 A10 = −1.16920E−12 
               
               
                 Surface No. 15 
               
               
                 K = 0.00000E+00, A4 = −7.12761E−05, A6 = −5.93385E−07, A8 = −3.61088E−09 
               
               
                 A10 = 1.71311E−11 
               
               
                 Surface No. 18 
               
               
                 K = 0.00000E+00, A4 = −6.97061E−05, A6 = 6.71417E−08, A8 = −7.80241E−10 
               
               
                 A10 = 1.83379E−11 
               
               
                 Surface No. 23 
               
               
                 K = 0.00000E+00, A4 = −2.66182E−05, A6 = −3.17290E−07, A8 = −2.35680E−11 
               
               
                 A10 = 8.15377E−11 
               
               
                 Surface No. 24 
               
               
                 K = 0.00000E+00, A4 = 7.62364E−06, A6 = 1.57830E−08, A8 = 8.23188E−11 
               
               
                 A10 = −2.12223E−13 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                 Zooming ratio 7.76981 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-angle 
                 Middle 
                 Telephoto 
               
               
                   
                 limit 
                 position 
                 limit 
               
               
                   
               
               
                 Focal length 
                 12.4203 
                 34.6205 
                 96.5032 
               
               
                 F-number 
                 4.00036 
                 5.00034 
                 5.80030 
               
               
                 View angle 
                 42.1346 
                 17.3551 
                 6.2652 
               
               
                 Image height 
                 10.0001 
                 10.8150 
                 10.8150 
               
               
                 BF 
                 18.0000 
                 18.0000 
                 18.0000 
               
               
                  d3 
                 0.7000 
                 17.6870 
                 34.5875 
               
               
                 d11 
                 34.8894 
                 17.9019 
                 1.0000 
               
               
                 d12 
                 15.7802 
                 3.8580 
                 2.0198 
               
               
                 d20 
                 1.6000 
                 3.8322 
                 6.6347 
               
               
                 d23 
                 4.9748 
                 14.6653 
                 13.7024 
               
               
                 Entrance pupil 
                 26.3007 
                 66.9820 
                 147.3127 
               
               
                 position 
               
               
                 Exit pupil 
                 −80.0580 
                 −117.0778 
                 −101.1309 
               
               
                 position 
               
               
                 Front principal 
                 36.7921 
                 91.3597 
                 151.7382 
               
               
                 points position 
               
               
                 Back principal 
                 119.4977 
                 97.3185 
                 35.5070 
               
               
                 points position 
               
               
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Lens 
                 Initial 
                 Focal 
                 Overall length 
                 Front principal 
                 Back principal 
               
               
                 unit 
                 surface No. 
                 length 
                 of lens unit 
                 points position 
                 points position 
               
               
                   
               
               
                 1 
                 1 
                 73.53274 
                 11.98520 
                 0.14570 
                 4.52812 
               
               
                 2 
                 4 
                 −13.95555 
                 14.86350 
                 0.41057 
                 3.42055 
               
               
                 3 
                 13 
                 17.10688 
                 17.87030 
                 8.41804 
                 8.94676 
               
               
                 4 
                 21 
                 −11.43637 
                 3.39760 
                 1.33394 
                 3.05080 
               
               
                 5 
                 24 
                 38.03094 
                 7.93900 
                 2.74375 
                 5.57027 
               
               
                   
               
            
           
         
       
     
     Numerical Example 2 
     The zoom lens system of Numerical Example 2 corresponds to Embodiment 2 shown in  FIG. 4 . Table 4 shows the surface data of the zoom lens system of Numerical Example 2. Table 5 shows the aspherical data. Table 6 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 37.98450 
                 1.50000 
                 1.94595 
                 18.0 
               
               
                  2 
                 29.34750 
                 7.51760 
                 1.77200 
                 50.0 
               
               
                  3* 
                 432.80370 
                 Variable 
               
               
                  4* 
                 −201.29530 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  5 
                 2129.91050 
                 1.00000 
                 1.91082 
                 35.2 
               
               
                  6 
                 11.92140 
                 5.50030 
               
               
                  7 
                 −40.82760 
                 0.60000 
                 1.88300 
                 40.8 
               
               
                  8 
                 44.14840 
                 0.20000 
               
               
                  9 
                 28.06360 
                 2.57340 
                 1.95906 
                 17.5 
               
               
                 10 
                 −422.15000 
                 Variable 
               
               
                 11 
                 ∞ 
                 1.00000 
               
               
                 (Diaphragm) 
               
               
                 12 
                 91.14680 
                 0.88440 
                 1.92286 
                 20.9 
               
               
                 13 
                 563.09830 
                 Variable 
               
               
                  14* 
                 11.60680 
                 5.29450 
                 1.51845 
                 70.0 
               
               
                  15* 
                 −30.97720 
                 0.20000 
               
               
                 16 
                 33.27480 
                 2.25000 
                 1.51680 
                 64.2 
               
               
                 17 
                 −65.21200 
                 0.55000 
                 2.00100 
                 29.1 
               
               
                 18 
                 13.51660 
                 1.30000 
               
               
                  19* 
                 16.51440 
                 3.72120 
                 1.58913 
                 61.3 
               
               
                  20* 
                 −25.64090 
                 Variable 
               
               
                 21 
                 −1172.65290 
                 2.56490 
                 1.92286 
                 20.9 
               
               
                 22 
                 −16.37850 
                 0.80000 
                 1.88202 
                 37.2 
               
               
                  23* 
                 17.37150 
                 Variable 
               
               
                  24* 
                 96.77980 
                 2.61040 
                 1.51845 
                 70.0 
               
               
                  25* 
                 −49.77210 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 (Aspherical data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 Surface No. 3 
               
               
                 K = 0.00000E+00, A4 = 1.19054E−06, A6 = −2.57541E−10, A8 = −4.29119E−13 
               
               
                 A10 = 7.51529E−16 
               
               
                 Surface No. 4 
               
               
                 K = 0.00000E+00, A4 = 2.64437E−05, A6 = −9.93943E−08, A8 = 4.24958E−10 
               
               
                 A10 = −1.05309E−12 
               
               
                 Surface No. 14 
               
               
                 K = 0.00000E+00, A4 = −5.97262E−05, A6 = −8.51313E−08, A8 = −2.68017E−09 
               
               
                 A10 = 8.10554E−12 
               
               
                 Surface No. 15 
               
               
                 K = 0.00000E+00, A4 = 9.63105E−06, A6 = 8.41305E−07, A8 = −9.97338E−09 
               
               
                 A10 = 5.51882E−11 
               
               
                 Surface No. 19 
               
               
                 K = 0.00000E+00, A4 = −1.05096E−04, A6 = 5.66408E−09, A8 = 2.63329E−08 
               
               
                 A10 = −3.91149E−13 
               
               
                 Surface No. 20 
               
               
                 K = 0.00000E+00, A4 = −3.34994E−05, A6 = −1.10627E−07, A8 = 2.33207E−08 
               
               
                 A10 = 1.24605E−10 
               
               
                 Surface No. 23 
               
               
                 K = 0.00000E+00, A4 = 3.28246E−05, A6 = 2.04303E−07, A8 = −1.89756E−08 
               
               
                 A10 = 2.73388E−10 
               
               
                 Surface No. 24 
               
               
                 K = 0.00000E+00, A4 = −9.43777E−06, A6 = −1.24057E−07, A8 = 8.68159E−09 
               
               
                 A10 = −6.86225E−11 
               
               
                 Surface No. 25 
               
               
                 K = 0.00000E+00, A4 = −2.64187E−05, A6 = −4.06586E−07, A8 = 1.17456E−08 
               
               
                 A10 = −8.00712E−11 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                 Zooming ratio 7.76939 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-angle 
                 Middle 
                 Telephoto 
               
               
                   
                 limit 
                 position 
                 limit 
               
               
                   
               
               
                 Focal length 
                 12.4205 
                 34.6206 
                 96.4995 
               
               
                 F-number 
                 4.15010 
                 5.09854 
                 5.80121 
               
               
                 View angle 
                 42.2965 
                 17.3197 
                 6.2524 
               
               
                 Image height 
                 10.0000 
                 10.8150 
                 10.8150 
               
               
                 BF 
                 18.0000 
                 18.0000 
                 18.0000 
               
               
                  d3 
                 0.7000 
                 14.3566 
                 25.6118 
               
               
                 d10 
                 25.9181 
                 12.2616 
                 1.0000 
               
               
                 d13 
                 15.2606 
                 5.6812 
                 0.7000 
               
               
                 d20 
                 1.6000 
                 4.2861 
                 9.3760 
               
               
                 d23 
                 4.3543 
                 11.2475 
                 11.1452 
               
               
                 Entrance pupil 
                 21.1584 
                 54.6785 
                 103.2825 
               
               
                 position 
               
               
                 Exit pupil 
                 −64.0054 
                 −60.4942 
                 −56.2361 
               
               
                 position 
               
               
                 Front principal 
                 31.1674 
                 69.5035 
                 34.0081 
               
               
                 points position 
               
               
                 Back principal 
                 93.5449 
                 71.4329 
                 9.4379 
               
               
                 points position 
               
               
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Lens 
                 Initial 
                 Focal 
                 Overall length 
                 Front principal 
                 Back principal 
               
               
                 unit 
                 surface No. 
                 length 
                 of lens unit 
                 points position 
                 points position 
               
               
                   
               
               
                 1 
                 1 
                 57.19177 
                 9.01760 
                 −0.77470 
                 3.28785 
               
               
                 2 
                 4 
                 −11.84029 
                 9.97370 
                 0.69682 
                 2.70510 
               
               
                 3 
                 11 
                 117.73404 
                 1.88440 
                 0.91125 
                 1.33613 
               
               
                 4 
                 14 
                 19.12181 
                 13.31570 
                 2.95733 
                 5.65879 
               
               
                 5 
                 21 
                 −20.37424 
                 3.36490 
                 1.75041 
                 3.35831 
               
               
                 6 
                 24 
                 63.78545 
                 2.61040 
                 1.14222 
                 2.02298 
               
               
                   
               
            
           
         
       
     
     Numerical Example 3 
     The zoom lens system of Numerical Example 3 corresponds to Embodiment 3 shown in  FIG. 7 . Table 7 shows the surface data of the zoom lens system of Numerical Example 3. Table 8 shows the aspherical data. Table 9 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 7 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 39.91790 
                 1.50000 
                 1.84666 
                 23.8 
               
               
                  2 
                 30.90600 
                 7.66790 
                 1.59282 
                 68.6 
               
               
                  3 
                 −488.48540 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  4* 
                 −486.00560 
                 Variable 
               
               
                  5* 
                 −151.62810 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  6 
                 −677.72420 
                 1.00000 
                 1.91082 
                 35.2 
               
               
                  7 
                 13.86270 
                 6.44730 
               
               
                  8 
                 −32.82990 
                 0.60000 
                 1.88300 
                 40.8 
               
               
                  9 
                 91.06540 
                 0.20000 
               
               
                 10 
                 40.26770 
                 2.97900 
                 1.95906 
                 17.5 
               
               
                 11 
                 −93.58000 
                 Variable 
               
               
                 12 
                 ∞ 
                 1.00000 
               
               
                 (Diaphragm) 
               
               
                 13 
                 63.40180 
                 1.11480 
                 1.48749 
                 70.4 
               
               
                 14 
                 −936.81530 
                 Variable 
               
               
                  15* 
                 12.77980 
                 3.67010 
                 1.51845 
                 70.0 
               
               
                  16* 
                 −98.55080 
                 0.20000 
               
               
                 17 
                 15.67900 
                 3.06940 
                 1.61310 
                 44.4 
               
               
                 18 
                 −74.00310 
                 0.55000 
                 1.91082 
                 35.2 
               
               
                 19 
                 10.97560 
                 1.43860 
               
               
                  20* 
                 19.42110 
                 3.99960 
                 1.58913 
                 61.3 
               
               
                 21 
                 −14.22940 
                 0.50000 
                 1.84666 
                 23.8 
               
               
                 22 
                 −22.48220 
                 Variable 
               
               
                 23 
                 105.02670 
                 2.53200 
                 1.92286 
                 20.9 
               
               
                 24 
                 −15.60570 
                 0.80000 
                 1.88202 
                 37.2 
               
               
                  25* 
                 12.69040 
                 Variable 
               
               
                  26* 
                 51.87660 
                 4.78460 
                 1.51845 
                 70.0 
               
               
                 27 
                 −23.89110 
                 0.70000 
                 2.00069 
                 25.5 
               
               
                 28 
                 −40.53650 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 8 
               
               
                   
               
               
                 (Aspherical data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 Surface No. 4 
               
               
                 K = 0.00000E+00, A4 = 1.30616E−06, A6 = −1.14924E−10, A8 = −8.86775E−13 
               
               
                 A10 = 1.24163E−15, A12 = −6.54677E−19, A14 = 1.61156E−21 
               
               
                 Surface No. 5 
               
               
                 K = 0.00000E+00, A4 = 2.51187E−05, A6 = −1.25139E−07, A8 = 5.64373E−10 
               
               
                 A10 = −1.37447E−12, A12 = 8.94268E−16, A14 = 0.00000E+00 
               
               
                 Surface No. 15 
               
               
                 K = 0.00000E+00, A4 = −3.36509E−05, A6 = −9.57334E−08, A8 = −9.08472E−10 
               
               
                 A10 = −8.52124E−12, A12 = 0.00000E+00, A14 = 0.00000E+00 
               
               
                 Surface No. 16 
               
               
                 K = 0.00000E+00, A4 = 7.79990E−07, A6 = 2.56834E−09, A8 = 6.20367E−11 
               
               
                 A10 = −7.08705E−12, A12 = 0.00000E+00, A14 = 0.00000E+00 
               
               
                 Surface No. 20 
               
               
                 K = 0.00000E+00, A4 = −3.85145E−05, A6 = −1.35207E−07, A8 = 3.75862E−09 
               
               
                 A10 = −2.89813E−11, A12 = −6.73117E−19, A14 = 0.00000E+00 
               
               
                 Surface No. 25 
               
               
                 K = 0.00000E+00, A4 = 1.28948E−05, A6 = −1.65633E−07, A8 = −5.74343E−09 
               
               
                 A10 = 6.49197E−11, A12 = 0.00000E+00, A14 = 0.00000E+00 
               
               
                 Surface No. 26 
               
               
                 K = 0.00000E+00, A4 = 2.36870E−05, A6 = 8.94156E−08, A8 = −4.73295E−10 
               
               
                 A10 = 1.33864E−12, A12 = 0.00000E+00, A14 = 0.00000E+00 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 9 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                 Zooming ratio 9.32125 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-angle 
                 Middle 
                 Telephoto 
               
               
                   
                 limit 
                 position 
                 limit 
               
               
                   
               
               
                 Focal length 
                 12.4210 
                 37.9215 
                 115.7797 
               
               
                 F-number 
                 4.15035 
                 5.26013 
                 5.80106 
               
               
                 View angle 
                 41.8150 
                 15.9456 
                 5.2258 
               
               
                 Image height 
                 10.0000 
                 10.8150 
                 10.8150 
               
               
                 BF 
                 14.6000 
                 14.6000 
                 14.6000 
               
               
                  d4 
                 0.7000 
                 17.4255 
                 35.0191 
               
               
                 d11 
                 35.3191 
                 18.5935 
                 1.0000 
               
               
                 d14 
                 16.6505 
                 2.5160 
                 0.7000 
               
               
                 d22 
                 1.9662 
                 3.3590 
                 7.5259 
               
               
                 d25 
                 4.3904 
                 17.1322 
                 14.7812 
               
               
                 Entrance pupil 
                 23.2799 
                 61.7160 
                 141.9922 
               
               
                 position 
               
               
                 Exit pupil 
                 −52.5185 
                 −64.7409 
                 −58.6876 
               
               
                 position 
               
               
                 Front principal 
                 32.7644 
                 77.4269 
                 29.2187 
               
               
                 points position 
               
               
                 Back principal 
                 106.1787 
                 80.6625 
                 2.7635 
               
               
                 points position 
               
               
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Lens 
                 Initial 
                 Focal 
                 Overall length 
                 Front principal 
                 Back principal 
               
               
                 unit 
                 surface No. 
                 length 
                 of lens unit 
                 points position 
                 points position 
               
               
                   
               
               
                 1 
                 1 
                 70.13468 
                 9.26790 
                 0.02077 
                 3.56211 
               
               
                 2 
                 5 
                 −14.19410 
                 11.32630 
                 0.30113 
                 2.17640 
               
               
                 3 
                 12 
                 121.85817 
                 2.11480 
                 1.04752 
                 1.41260 
               
               
                 4 
                 15 
                 19.98649 
                 13.42770 
                 2.09841 
                 5.18696 
               
               
                 5 
                 23 
                 −17.54708 
                 3.33200 
                 2.06209 
                 3.61986 
               
               
                 6 
                 26 
                 69.27198 
                 5.48460 
                 1.61886 
                 3.53478 
               
               
                   
               
            
           
         
       
     
     Numerical Example 4 
     The zoom lens system of Numerical Example 4 corresponds to Embodiment 4 shown in  FIG. 10 . Table 10 shows the surface data of the zoom lens system of Numerical Example 4. Table 11 shows the aspherical data. Table 12 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 10 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 48.87620 
                 9.63280 
                 1.57773 
                 62.7 
               
               
                  2* 
                 −661.45610 
                 Variable 
               
               
                  3* 
                 −156.94960 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  4 
                 794.29560 
                 1.00000 
                 1.91082 
                 35.2 
               
               
                  5 
                 13.86790 
                 6.14990 
               
               
                  6 
                 −25.23620 
                 0.60000 
                 1.88300 
                 40.8 
               
               
                  7 
                 209.40780 
                 0.20000 
               
               
                  8 
                 65.44040 
                 2.28270 
                 1.95906 
                 17.5 
               
               
                  9 
                 −55.42720 
                 Variable 
               
               
                 10 
                 ∞ 
                 1.00000 
               
               
                 (Diaphragm) 
               
               
                 11 
                 54.97370 
                 1.00960 
                 1.92647 
                 27.3 
               
               
                 12 
                 140.21440 
                 Variable 
               
               
                  13* 
                 11.50950 
                 5.16460 
                 1.51845 
                 70.0 
               
               
                  14* 
                 −29.66380 
                 0.20000 
               
               
                 15 
                 53.55780 
                 2.57060 
                 1.51680 
                 64.2 
               
               
                 16 
                 −35.50580 
                 0.55000 
                 2.00100 
                 29.1 
               
               
                 17 
                 14.41840 
                 1.30000 
               
               
                  18* 
                 17.21190 
                 5.70470 
                 1.58913 
                 61.3 
               
               
                  19* 
                 −20.90470 
                 Variable 
               
               
                 20 
                 −479.41410 
                 4.66080 
                 1.92286 
                 20.9 
               
               
                 21 
                 −10.47850 
                 0.80000 
                 1.88202 
                 37.2 
               
               
                  22* 
                 14.85420 
                 Variable 
               
               
                  23* 
                 33.49970 
                 4.00230 
                 1.51845 
                 70.0 
               
               
                  24* 
                 −168.17080 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 11 
               
               
                   
               
               
                 (Aspherical data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 Surface No. 2 
               
               
                 K = 0.00000E+00, A4 = 1.35387E−06, A6 = −2.77397E−09, A8 = 1.24762E−11 
               
               
                 A10 = −2.11268E−14 
               
               
                 Surface No. 3 
               
               
                 K = 0.00000E+00, A4 = 3.09025E−05, A6 = −2.03946E−07, A8 = 1.22351E−09 
               
               
                 A10 = −3.34324E−12 
               
               
                 Surface No. 13 
               
               
                 K = 0.00000E+00, A4 = −6.11018E−05, A6 = −4.84088E−08, A8 = −2.73108E−09 
               
               
                 A10 = −1.00566E−11 
               
               
                 Surface No. 14 
               
               
                 K = 0.00000E+00, A4 = 5.08440E−06, A6 = 7.69362E−07, A8 = −9.13172E−09 
               
               
                 A10 = 4.18510E−11 
               
               
                 Surface No. 18 
               
               
                 K = 0.00000E+00, A4 = −9.66849E−05, A6 = −3.46095E−08, A8 = 1.73619E−08 
               
               
                 A10 = −1.01549E−10 
               
               
                 Surface No. 19 
               
               
                 K = 0.00000E+00, A4 = 1.60513E−06, A6 = −3.99441E−07, A8 = 1.86779E−08 
               
               
                 A10 = −6.91678E−11 
               
               
                 Surface No. 22 
               
               
                 K = 0.00000E+00, A4 = 2.84621E−05, A6 = 5.43768E−07, A8 = −1.53477E−08 
               
               
                 A10 = 1.63961E−10 
               
               
                 Surface No. 23 
               
               
                 K = 0.00000E+00, A4 = 9.62399E−06, A6 = −5.77267E−07, A8 = 9.07172E−09 
               
               
                 A10 = −6.96748E−11 
               
               
                 Surface No. 24 
               
               
                 K = 0.00000E+00, A4 = −2.43880E−05, A6 = −8.03498E−07, A8 = 1.04752E−08 
               
               
                 A10 = −6.92387E−11 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                 Zooming ratio 5.99932 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-angle 
                 Middle 
                 Telephoto 
               
               
                   
                 limit 
                 position 
                 limit 
               
               
                   
               
               
                 Focal length 
                 13.5018 
                 33.0689 
                 81.0015 
               
               
                 F-number 
                 4.15076 
                 5.13167 
                 5.80068 
               
               
                 View angle 
                 39.3542 
                 19.1808 
                 7.9232 
               
               
                 Image height 
                 10.0000 
                 10.8150 
                 10.8150 
               
               
                 BF 
                 14.6000 
                 14.6000 
                 14.6000 
               
               
                  d2 
                 2.7655 
                 16.9948 
                 27.7019 
               
               
                  d9 
                 25.9558 
                 11.7282 
                 1.0000 
               
               
                 d12 
                 19.6131 
                 8.6892 
                 0.7000 
               
               
                 d19 
                 1.6000 
                 4.4082 
                 12.9018 
               
               
                 d22 
                 5.5374 
                 13.6514 
                 13.1681 
               
               
                 Entrance pupil 
                 24.8483 
                 52.1429 
                 78.9404 
               
               
                 position 
               
               
                 Exit pupil 
                 −72.6674 
                 −74.1695 
                 −63.6811 
               
               
                 position 
               
               
                 Front principal 
                 35.8366 
                 70.4535 
                 56.9382 
               
               
                 points position 
               
               
                 Back principal 
                 103.3601 
                 83.8590 
                 36.0163 
               
               
                 points position 
               
               
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Lens 
                 Initial 
                 Focal 
                 Overall length 
                 Front principal 
                 Back principal 
               
               
                 unit 
                 surface No. 
                 length 
                 of lens unit 
                 points position 
                 points position 
               
               
                   
               
               
                 1 
                 1 
                 79.17270 
                 9.63280 
                 0.42220 
                 3.91904 
               
               
                 2 
                 3 
                 −13.34012 
                 10.33260 
                 0.60397 
                 2.25328 
               
               
                 3 
                 10 
                 97.05103 
                 2.00960 
                 0.66393 
                 1.15243 
               
               
                 4 
                 13 
                 20.37881 
                 15.48990 
                 4.23369 
                 6.80180 
               
               
                 5 
                 20 
                 −17.35657 
                 5.46080 
                 2.76808 
                 5.39450 
               
               
                 6 
                 23 
                 54.24941 
                 4.00230 
                 0.44082 
                 1.78936 
               
               
                   
               
            
           
         
       
     
     Numerical Example 5 
     The zoom lens system of Numerical Example 5 corresponds to Embodiment 5 shown in  FIG. 13 . Table 13 shows the surface data of the zoom lens system of Numerical Example 5. Table 14 shows the aspherical data. Table 15 shows the various data. 
     
       
         
           
               
             
               
                 TABLE 13 
               
             
            
               
                   
               
               
                 (Surface data) 
               
            
           
           
               
               
               
               
               
            
               
                 Surface number 
                 r 
                 d 
                 nd 
                 vd 
               
               
                   
               
               
                 Object surface 
                 ∞ 
                   
                   
                   
               
               
                  1 
                 36.59920 
                 1.50000 
                 1.94595 
                 18.0 
               
               
                  2 
                 28.90140 
                 8.41430 
                 1.77200 
                 50.0 
               
               
                  3* 
                 214.15640 
                 Variable 
               
               
                  4* 
                 −1575.65170 
                 0.10000 
                 1.51358 
                 51.6 
               
               
                  5 
                 144.30370 
                 1.00000 
                 1.91082 
                 35.2 
               
               
                  6 
                 11.95830 
                 6.71610 
               
               
                  7 
                 −36.98810 
                 0.60000 
                 1.88300 
                 40.8 
               
               
                  8 
                 41.77810 
                 0.20000 
               
               
                  9 
                 29.52340 
                 4.32200 
                 1.95906 
                 17.5 
               
               
                 10 
                 −117.58210 
                 Variable 
               
               
                 11 
                 ∞ 
                 1.10000 
               
               
                 (Diaphragm) 
               
               
                 12 
                 170.71840 
                 0.91390 
                 1.49798 
                 63.7 
               
               
                 13 
                 149.23820 
                 Variable 
               
               
                  14* 
                 11.64090 
                 6.55410 
                 1.51845 
                 70.0 
               
               
                  15* 
                 −29.47400 
                 0.20000 
               
               
                 16 
                 27.23250 
                 2.57660 
                 1.52804 
                 51.5 
               
               
                 17 
                 −117.03240 
                 0.55000 
                 2.00100 
                 29.1 
               
               
                 18 
                 12.33240 
                 1.30000 
               
               
                  19* 
                 13.52470 
                 3.94140 
                 1.59315 
                 61.7 
               
               
                  20* 
                 −41.17780 
                 Variable 
               
               
                 21 
                 92.66690 
                 2.81200 
                 1.92286 
                 20.9 
               
               
                 22 
                 −18.08640 
                 0.80000 
                 1.88202 
                 37.2 
               
               
                  23* 
                 13.72040 
                 Variable 
               
               
                  24* 
                 31.56050 
                 6.64980 
                 1.51845 
                 70.0 
               
               
                  25* 
                 −298.60090 
                 (BF) 
               
               
                 Image surface 
                 ∞ 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 14 
               
               
                   
               
               
                 (Aspherical data) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 Surface No. 3 
               
               
                 K = 0.00000E+00, A4 = 1.12677E−06, A6 = −1.47652E−13, A8 = −7.64558E−13 
               
               
                 A10 = 1.09296E−15 
               
               
                 Surface No. 4 
               
               
                 K = 0.00000E+00, A4 = 2.69315E−05, A6 = −1.20850E−07, A8 = 4.53281E−10 
               
               
                 A10 = −7.38292E−13 
               
               
                 Surface No. 14 
               
               
                 K = 0.00000E+00, A4 = −6.85498E−05, A6 = −1.27329E−07, A8 = −2.43416E−09 
               
               
                 A10 = 2.95680E−12 
               
               
                 Surface No. 15 
               
               
                 K = 0.00000E+00, A4 = 4.03658E−06, A6 = 7.59479E−07, A8 = −8.88871E−09 
               
               
                 A10 = 5.36562E−11 
               
               
                 Surface No. 19 
               
               
                 K = 0.00000E+00, A4 = −9.11454E−05, A6 = 1.20205E−07, A8 = 1.77368E−08 
               
               
                 A10 = −4.83718E−11 
               
               
                 Surface No. 20 
               
               
                 K = 0.00000E+00, A4 = −1.40896E−05, A6 = −1.60923E−07, A8 = 2.82366E−08 
               
               
                 A10 = −8.55701E−11 
               
               
                 Surface No. 23 
               
               
                 K = 0.00000E+00, A4 = 3.09752E−05, A6 = 7.73439E−07, A8 = −2.96910E−08 
               
               
                 A10 = 3.90874E−10 
               
               
                 Surface No. 24 
               
               
                 K = 0.00000E+00, A4 = 5.18028E−06, A6 = −2.59282E−07, A8 = 8.27182E−09 
               
               
                 A10 = −5.75036E−11 
               
               
                 Surface No. 25 
               
               
                 K = 0.00000E+00, A4 = −4.23975E−05, A6 = −7.10044E−07, A8 = 1.20635E−08 
               
               
                 A10 = −6.29552E−11 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15 
               
               
                   
               
               
                 (Various data) 
               
               
                   
               
             
            
               
                 Zooming ratio 7.76792 
               
            
           
           
               
               
               
               
            
               
                   
                 Wide-angle 
                 Middle 
                 Telephoto 
               
               
                   
                 limit 
                 position 
                 limit 
               
               
                   
               
               
                 Focal length 
                 12.4197 
                 34.6192 
                 96.4755 
               
               
                 F-number 
                 4.14995 
                 5.16591 
                 5.80062 
               
               
                 View angle 
                 42.2496 
                 19.1414 
                 6.8945 
               
               
                 Image height 
                 10.0000 
                 10.8150 
                 10.8150 
               
               
                 BF 
                 14.5690 
                 14.5690 
                 14.5960 
               
               
                  d3 
                 0.9941 
                 15.1024 
                 26.1956 
               
               
                 d10 
                 26.2020 
                 12.0936 
                 1.0000 
               
               
                 d13 
                 15.1656 
                 6.5879 
                 0.7000 
               
               
                 d20 
                 1.6000 
                 4.7995 
                 9.7808 
               
               
                 d23 
                 4.8494 
                 10.2277 
                 11.1347 
               
               
                 Entrance pupil 
                 24.1354 
                 61.4591 
                 115.0912 
               
               
                 position 
               
               
                 Exit pupil 
                 −65.4665 
                 −59.8758 
                 −57.0531 
               
               
                 position 
               
               
                 Front principal 
                 34.1970 
                 76.0478 
                 48.1828 
               
               
                 points position 
               
               
                 Back principal 
                 101.1572 
                 78.9684 
                 17.0690 
               
               
                 points position 
               
               
                   
               
            
           
           
               
            
               
                 Zoom lens unit data 
               
            
           
           
               
               
               
               
               
               
            
               
                 Lens 
                 Initial 
                 Focal 
                 Overall length 
                 Front principal 
                 Back principal 
               
               
                 unit 
                 surface No. 
                 length 
                 of lens unit 
                 points position 
                 points position 
               
               
                   
               
               
                 1 
                 1 
                 59.68106 
                 9.91430 
                 −1.46905 
                 3.07232 
               
               
                 2 
                 4 
                 −13.03825 
                 12.93810 
                 0.50436 
                 3.06385 
               
               
                 3 
                 11 
                 −2415.99304 
                 2.01390 
                 6.01837 
                 6.31343 
               
               
                 4 
                 14 
                 18.69245 
                 15.12210 
                 2.57083 
                 6.01949 
               
               
                 5 
                 21 
                 −19.67248 
                 3.61200 
                 2.32028 
                 4.00039 
               
               
                 6 
                 24 
                 55.43687 
                 6.64980 
                 0.42152 
                 2.66167 
               
               
                   
               
            
           
         
       
     
     The following Table 16 shows the corresponding values to the individual conditions in the zoom lens systems of each of Numerical Examples. 
     
       
         
           
               
             
               
                 TABLE 16 
               
             
            
               
                   
               
               
                 (Values corresponding to conditions) 
               
            
           
           
               
               
            
               
                   
                 Numerical Example 
               
            
           
           
               
               
               
               
               
               
            
               
                 Condition 
                 1 
                 2 
                 3 
                 4 
                 5 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 (1) 
                 L T /f T   
                 1.37 
                 1.10 
                 1.02 
                 1.44 
                 1.18 
               
               
                 (2) 
                 (f T /f W ) × (tan(θ W ) 2   
                 6.36 
                 6.43 
                 7.46 
                 4.03 
                 6.41 
               
               
                 (3) 
                 f W /T 1G   
                 1.04 
                 1.38 
                 1.34 
                 1.40 
                 1.25 
               
               
                 (4) 
                 Y T /T 1G   
                 0.90 
                 1.20 
                 1.17 
                 1.12 
                 1.09 
               
               
                 (5) 
                 f W /T imgG   
                 1.56 
                 4.76 
                 2.26 
                 3.37 
                 1.87 
               
               
                 (6) 
                 Y T /T imgG   
                 1.36 
                 4.14 
                 1.97 
                 2.70 
                 1.63 
               
               
                 (7) 
                 f W /T air1G2GW   
                 17.74 
                 17.74 
                 17.74 
                 4.88 
                 12.49 
               
               
                 (8) 
                 nd 1G   
                 1.55 
                 1.77 
                 1.59 
                 1.58 
                 1.77 
               
               
                 (9) 
                 vd 1G   
                 71.70 
                 50.00 
                 68.60 
                 62.70 
                 50.00 
               
               
                 (10)  
                 |M 2G /f W | 
                 2.73 
                 2.01 
                 2.76 
                 1.85 
                 2.03 
               
               
                 (11)  
                 |M 2G /Y T | 
                 3.13 
                 2.30 
                 3.17 
                 2.31 
                 2.33 
               
               
                 (12)  
                 f W /T 2G   
                 0.84 
                 1.25 
                 1.10 
                 1.31 
                 0.96 
               
               
                 (13)  
                 f T /T 2G   
                 6.49 
                 9.68 
                 10.22 
                 7.84 
                 7.46 
               
               
                   
               
            
           
         
       
     
     The present disclosure is applicable to a digital still camera, a digital video camera, a camera for a mobile terminal device such as a smart-phone, a camera for a PDA (Personal Digital Assistance), a surveillance camera in a surveillance system, a Web camera, a vehicle-mounted camera or the like. In particular, the present disclosure is applicable to a photographing optical system where high image quality is required like in a digital still camera system or a digital video camera system. 
     Also, the present disclosure is applicable to, among the interchangeable lens apparatuses in the present disclosure, an interchangeable lens apparatus having motorized zoom function, i.e., activating function for the zoom lens system by a motor, with which a digital video camera system is provided. 
     As described above, embodiments have been described as examples of art in the present disclosure. Thus, the attached drawings and detailed description have been provided. 
     Therefore, in order to illustrate the art, not only essential elements for solving the problems but also elements that are not necessary for solving the problems may be included in elements appearing in the attached drawings or in the detailed description. Therefore, such unnecessary elements should not be immediately determined as necessary elements because of their presence in the attached drawings or in the detailed description. 
     Further, since the embodiments described above are merely examples of the art in the present disclosure, it is understood that various modifications, replacements, additions, omissions, and the like can be performed in the scope of the claims or in an equivalent scope thereof.