Patent Publication Number: US-7586683-B2

Title: Zoom lens, still image camera comprising the zoom lens, and video camera comprising the zoom lens

Description:
This application is a Division of application Ser. No. 11/067,432, filed Feb. 22, 2005, which is a Continuation-in-Part of application Ser. No. 09/701,754 filed Dec. 1, 2000, which is a National Stage of PCT/JP99/02910 filed May 31, 1999 which applications are incorporated herein by reference. 

   TECHNICAL FIELD 
   The present invention relates to a zoom lens used for a video camera or the like, and the zoom lens has a function optically to correct image movement caused by camera shake, vibration or the like. 
   BACKGROUND ART 
   Motion picture cameras such as video cameras have been required to have a function to prevent vibration caused by camera shake, and various types of vibration-proof optical systems have been disclosed. For example, a zoom lens disclosed in JP-A-8-29737 includes an optical system consisting of two parts attached in front of the zoom lens in order to correct camera shake, where either of the parts is moved vertically to an optical axis in order to correct movement of images caused by camera shake. 
   A zoom lens disclosed in JP-A-7-128619 comprises four groups, where a part of the third lens group comprising plural lenses is moved vertically to the optical axis in order to correct the movement of images caused by camera shake. 
   However, the zoom lens disclosed in JP-A-8-29737 has an increased lens diameter for an optical system to correct camera shake for the purpose of attaching the optical system in front of the zoom lens. Accordingly, the entire component is upsized and a load on a driving system will be heavier. As a result, the zoom lens is unfavorable in view of downsizing, weight-reduction and power-saving. 
   The zoom lens disclosed in JP-A-7-128619 corrects image movement caused by camera shake by moving a part of the third lens group vertically to the optical axis while the same lens group is fixed with respect to the image plane. This type of zoom lens is more favorable than a zoom lens of front-attachment type in view of downsizing, but a load on the actuator will be heavier since the lens group for correcting camera shake is composed of three lenses. 
   Since an optical system for correcting camera shake is attached in front of the zoom lens disclosed in JP-A-8-29737, the lens diameter of the optical system will be increased, and the entire component will be upsized. So a load on the driving system will be heavier, and thus, this zoom lens is unfavorable in view of downsizing, weight reduction and power-saving. 
   The latter zoom lens in JP-A-7-128619 is advantageous in downsizing and weight reduction when compared to a type comprising an optical system for correcting camera shake in front of the zoom lens, since a third lens group is fixed with respect to the image plane and a part thereof is moved vertically with respect to the optical axis. However, the zoom lens has a problem of deterioration in aberration, especially for chromatic aberration, when shifting lenses, since a part of the third lens group is moved. 
   DISCLOSURE OF INVENTION 
   A purpose of the present invention is to resolve the above mentioned problems in conventional zoom lenses by providing a small and compact zoom lens with less deterioration in the aberration performance and also a video camera using the same. 
   For this purpose, a first zoom lens of the present invention comprises a first lens group having a positive refracting power and being fixed with respect to an image plane, a second lens group having a negative refracting power and varying power by moving along an optical axis, a third lens group having a positive refracting power and being fixed with respect to the image plane, and a fourth lens group having a positive refracting power and moving along an optical axis so as to keep the image plane varied by a shift of the second lens group and an object at a predetermined position from a reference surface, and the first to the fourth lens group are disposed from the object in this order. The present invention is characterized in that the entire third lens group is moved vertically with respect to the optical axis so as to correct movement of an image during camera shake. 
   Accordingly, the zoom lens can be downsized when compared to a type of zoom lens comprising an optical system for correcting camera shake attached in front of the lens. Furthermore, since the entire group having a united optical performance is decentered, deterioration in the aberration can be decreased when compared to a zoom lens in which only a part in the groups are moved. 
   In the first zoom lens mentioned above, preferably the third group is composed of one lens. Accordingly, a load on the driving system will be decreased when correcting camera shake, and power consumption can be saved. 
   Preferably the third lens group is composed of two lenses: a positive lens and a negative lens. Accordingly, the aberration when correcting camera shake can be corrected more efficiently, and deterioration of image quality can be decreased even when correcting camera shake. 
   Preferably the third lens group is composed of three lenses comprising at least one positive lens and at least one negative lens. The third lens group is required to have a strong positive power to decrease the full length in order to obtain a small zoom lens. In this preferable embodiment, aberration occurring at this time can be corrected with the three lenses. 
   It is also preferable that the third lens group includes a positive lens, and a cemented lens of a positive lens and a negative lens. Accordingly, tolerance when assembling a group of correcting lenses can be eased. 
   Preferably the third lens group is composed of at least one aspherical surface. Accordingly, aberration when correcting camera shake can be corrected with further efficiency, and thus, performance when moving the lenses can be improved. 
   Preferably the fourth lens group comprises at least one aspherical surface. Accordingly, aberration when correcting camera shake can be corrected as well as when a stationary state with further efficiency. 
   Preferably, the shifting amount Y of the third lens group at a focal length f of an entire system when correcting camera shake, the shifting amount Yt of the third lens group at a telephoto end, and the focal length ft of the telephoto end satisfy the following conditional expressions.
 
Yt&gt;Y; and
 
( Y/Yt )/( f/ft )&lt;1.5
 
Accordingly, deterioration in the optical performance can be prevented when camera shake occurs.
 
   Preferably, a focal length f 3  of the third lens group and a focal length fw of an entire system at a wide-angle end satisfy the following conditional expression.
 
2.0 &lt;f 3 /fw &lt;4.0
 
Accordingly, the shifting amount when correcting camera shake can be decreased and the zoom lens can be shortened as a whole, and thus, a small zoom lens can be provided.
 
   Preferably, a surface on the object side of a lens disposed closest to the object side in the third lens group is aspherical, and a local radius of curvature R 10  in the vicinity of an optical axis and a local radius of curvature R 11  in an outer peripheral portion satisfy the following conditional expression.
 
1.05&lt; R 11/ R 10&lt;2.5
 
Accordingly, spherical aberration can be corrected satisfactorily.
 
   Preferably, a surface on the object side of a lens disposed closest to the object side in the fourth lens group is aspherical, and a local radius of curvature R 20  in the vicinity of an optical axis and a local radius of curvature R 21  in an outer peripheral portion satisfy the following conditional expression.
 
1.05&lt; R 21/ R 20&lt;2.0
 
Accordingly, coma-aberration on the upper flux of the off-axis ray can be corrected favorably.
 
   Next, a first video camera of the present invention is characterized in that it includes the above-mentioned first zoom lens. Accordingly, the video camera has a function to correct camera shake and can be downsized and weight-reduced. 
   Next, a second zoom lens of the present invention comprises a first lens group having a positive refracting power and being fixed with respect to an image plane; a second lens group having a negative refracting power and varying power by moving along an optical axis; a third lens group fixed with respect to the image plane; a fourth lens group fixed with respect to the image plane; and a fifth lens group having a positive refracting power and moving along an optical axis so as to keep the image plane varied by a shift of the second lens group and an object at a predetermined position from a reference surface. In this zoom lens, the first to the fifth lens groups are disposed from the object side in this order. The third lens group and the fourth lens group compose a combination of a lens group having a positive refracting power and a lens group having a negative refracting power, and either the third or fourth lens group is moved vertically with respect to the optical axis so as to correct movement of the image during camera shake. 
   In such a zoom lens, camera shake is corrected by moving lenses with smaller diameter. Therefore, this type of zoom lens is favorable in downsizing when compared to a zoom lens comprising an optical system for correcting camera shake attached in front of the lens. Moreover, since the aberration performance for each lens group can be adjusted, the aberration performance will deteriorate less when correcting camera shake. 
   In the second zoom lens, preferably either the third or fourth lens group that is moved is vertically with respect to the optical axis so as to correct movement of the image during camera shake is composed of two lenses: one positive lens and one negative lens. 
   It is also preferable that the third lens group has a positive refracting power and the fourth lens group has a negative refracting power, and the third lens group is moved vertically with respect to the optical axis so as to correct movement of the image during camera shake. In such a zoom lens, long back focus can be secured easily since the fourth lens group includes lenses having a negative refracting power. This is suitable for an optical system of a video camera using three imaging devices, which requires a long back focus. 
   Preferably, the fourth lens group is composed of two lenses separated from each other: one positive lens and one negative lens. 
   Preferably, the fourth lens group is composed of two cemented lenses: one positive lens and one negative lens. 
   Preferably, the third lens group has a negative refracting power and the fourth lens group has a positive refracting power, and the fourth lens group is moved vertically with respect to the optical axis so as to correct movement of the image during camera shake. Since the fourth lens group includes lenses having a positive refracting power in such a zoom lens, light entering the fifth lens group can be lowered and the lens diameter also can be reduced. Therefore, a load on a focusing actuator can be lighter. 
   Preferably, the third lens group and the fourth lens group are composed two lenses respectively, and Abbe&#39;s number v31 of one lens of the third group, Abbe&#39;s number v32 of the remaining lens of the third group, Abbe&#39;s number v41 of one lens of the fourth group and Abbe&#39;s number v42 of the remaining lens of the fourth group satisfy the following conditional expressions.
 
|v31-v32|&gt;25
 
|v41-v42|&gt;25
 
Since such a zoom lens can provide a sufficient achromatic effect, deterioration in magnification chromatic aberration can be decreased even when shifting the lenses.
 
   Preferably, either the third or fourth lens group that is moved vertically with respect to the optical axis in order to correct movement of an image during camera shake is composed of two lenses: one lens having a positive refracting power and one lens having a negative refracting power being disposed separately from the object side in this order, and the lenses have sag amounts equal on the object side and on the image side. 
   Preferably, either the third or fourth lens group that group is moved vertically with respect to the optical axis in order to correct movement of an image during camera shake is composed of three lenses comprising at least one positive lens and at least one negative lens. In a small zoom lens, the third lens group is required to have a strong positive power to decrease the whole length. Aberrations occurring at this time can be corrected by using three lenses in this embodiment. 
   Preferably, either the third or fourth lens group that is moved vertically with respect to the optical axis in order to correct movement of an image during camera shake is composed of one lens. Accordingly, a load on the driving system will be lighter when correcting camera shake and power consumption can be decreased. 
   Preferably, either the third or fourth lens group that is moved vertically with respect to the optical axis in order to correct movement of an image during camera shake comprises at least one aspherical surface. Such a zoom lens can have improved performance during lens shifting. 
   Preferably, either the third or fourth lens group that is moved vertically with respect to the optical axis in order to correct movement of an image during camera shake comprises a convex lens having an aspherical surface when viewed from the object side, and a local radius of curvature rS 1  for a diameter occupying 10% of lens effective diameter and a local radius of curvature rS 9  for a diameter occupying 90% of lens effective diameter satisfy the following conditional expression.
 
0.01&lt; rS 1/ rS 9&lt;2.00
 
Such a zoom lens can provide sufficient aberration performance.
 
   Preferably, a focal length f 3  of the third lens group and a focal length f 34  of a composite focal length of the third and fourth lens groups satisfy the following conditional expression.
 
0.40&lt;| f 3/ f 34|&lt;0.85
 
   Since such a zoom lens can control the power of the correcting lenses, deterioration in the aberration performance can be prevented and moreover, degree of lens movement when correcting camera shake can be controlled. Therefore, the lens can be made smaller, and this is favorable for downsizing. 
   Preferably, a focal length fw of an entire system at the wide-angle end and a distance BF between the final surface of the lens and the image plane in the air satisfy the following conditional expression.
 
2.0&lt;BF&lt;fw&lt;5.0
 
Accordingly, a zoom lens with a long back focus can be provided. Preferably, a focal length fw of an entire system at the wide-angle end, focal length fi (i=1−5) of the i-th lens group, and a composite focal length f 34  of the third and fourth lens groups satisfy the following expressions.
 
5.0&lt; f 1/ fw&lt; 8.0
 
0.5&lt;| f 2|/ fw&lt; 1.6
 
4.0&lt; f 34/ fw&lt; 9.5
 
2.0&lt; f 5/ fw&lt; 5.0
 
Accordingly, a small zoom lens can be provided.
 
   It is also preferable that the shifting amount Y of the third lens group at a focal length f of an entire system when correcting camera shake, the shifting amount Yt of the third lens group at a telephoto end and a focal length ft of the telephoto end satisfy the following conditional expressions.
 
Yt&gt;Y; and
 
( Y/Yt )/( f/ft )&lt;1.5
 
Accordingly, overcorrection and also deterioration in the optical performance can be prevented.
 
   Next, a second video camera of the present invention is characterized in that it comprises the second zoom lens. Accordingly, a small video camera with high-performance and a function to correct camera shake is obtainable. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a view showing the arrangement of a zoom lens in a first embodiment according to the present invention. 
       FIG. 2  illustrates various aberrations at a wide-angle end in the first embodiment according to the present invention. 
       FIG. 3  illustrates various aberrations at a standard position in the first embodiment according to the present invention. 
       FIG. 4  illustrates various aberrations at a telephoto end in the first embodiment according to the present invention. 
       FIG. 5  is a view showing the arrangement of a zoom lens in a second embodiment according to the present invention. 
       FIG. 6  illustrates various aberrations at a wide-angle end in the second embodiment according to the present invention. 
       FIG. 7  illustrates various aberrations at a standard position in the second embodiment according to the present invention. 
       FIG. 8  illustrates various aberrations at a telephoto end in the second embodiment according to the present invention. 
       FIG. 9  is a view showing the arrangement of a zoom lens in a third embodiment according to the present invention. 
       FIG. 10  illustrates various aberrations at a wide-angle end in the third embodiment according to the present invention. 
       FIG. 11  illustrates various aberrations at a standard position in the third embodiment according to the present invention. 
       FIG. 12  illustrates various aberrations at a telephoto end in the third embodiment according to the present invention. 
       FIG. 13  is a view showing the arrangement of a zoom lens in a fourth embodiment according to the present invention. 
       FIG. 14  illustrates various aberrations at a wide-angle end in the fourth embodiment according to the present invention. 
       FIG. 15  illustrates various aberrations at a standard position in the fourth embodiment according to the present invention. 
       FIG. 16  illustrates various aberrations at a telephoto end in the fourth embodiment according to the present invention. 
       FIG. 17  is a view showing the arrangement of a zoom lens in a fifth embodiment according to the present invention. 
       FIG. 18  illustrates various aberrations at a wide-angle end in the fifth embodiment according to the present invention. 
       FIG. 19  illustrates various aberrations at a standard position in the fifth embodiment according to the present invention. 
       FIG. 20  illustrates various aberrations at a telephoto end in the fifth embodiment according to the present invention. 
       FIG. 21  illustrates various aberrations at a wide-angle end of a second example in the fifth embodiment according to the present invention. 
       FIG. 22  illustrates various aberrations at a standard position of the second example in the fifth embodiment according to the present invention. 
       FIG. 23  illustrates various aberrations at a telephoto end of the second example in the fifth embodiment according to the present invention. 
       FIG. 24  is a view showing the arrangement of a zoom lens in a sixth embodiment according to the present invention. 
       FIG. 25  illustrates various aberrations at a wide-angle end in the sixth embodiment according to the present invention. 
       FIG. 26  illustrates various aberrations at a standard position in the sixth embodiment according to the present invention. 
       FIG. 27  illustrates various aberrations at a telephoto end in the sixth embodiment according to the present invention. 
       FIG. 28  illustrates various aberrations at a telephoto end in the sixth embodiment according to the present invention at a correction of 0.5 degrees. 
       FIG. 29  is a view showing the arrangement of a zoom lens in a seventh embodiment according to the present invention. 
       FIG. 30  illustrates various aberrations at a wide-angle end in the seventh embodiment according to the present invention. 
       FIG. 31  illustrates various aberrations at a standard position in the seventh embodiment according to the present invention. 
       FIG. 32  illustrates various aberrations at a telephoto end in the seventh embodiment according to the present invention. 
       FIG. 33  illustrates various aberrations at a telephoto end in the seventh embodiment according to the present invention at a correction of 0.5 degrees. 
       FIG. 34  is a view showing the arrangement of a zoom lens in a eighth embodiment according to the present invention. 
       FIG. 35  illustrates various aberrations at a wide-angle end in the eighth embodiment according to the present invention. 
       FIG. 36  illustrates various aberrations at a standard position in the eighth embodiment according to the present invention. 
       FIG. 37  illustrates various aberrations at a telephoto end in the eighth embodiment according to the present invention. 
       FIG. 38  illustrates various aberrations at a telephoto end in the eighth embodiment according to the present invention at a correction of 0.5 degrees. 
       FIG. 39  is a view showing the arrangement of a zoom lens in a ninth embodiment according to the present invention. 
       FIG. 40  illustrates various aberrations at a wide-angle end in the ninth embodiment according to the present invention. 
       FIG. 41  illustrates various aberrations at a standard position in the ninth embodiment according to the present invention. 
       FIG. 42  illustrates various aberrations at a telephoto end in the ninth embodiment according to the present invention. 
       FIG. 43  illustrates various aberrations at a telephoto end in the ninth embodiment according to the present invention at a correction of 0.5 degrees. 
       FIG. 44  is a view showing the arrangement of a video camera in a tenth embodiment according to the present invention. 
       FIG. 45  is a view showing the arrangement of a zoom lens in an eleventh embodiment according to the present invention. 
       FIG. 46  is a view specifically showing the arrangement of the zoom lens in the eleventh embodiment according to the present invention. 
       FIG. 47  illustrates various aberrations at a wide-angle end in the eleventh embodiment according to the present invention. 
       FIG. 48  illustrates various aberrations at a standard position in the eleventh embodiment according to the present invention. 
       FIG. 49  illustrates various aberrations at a telephoto end in the eleventh embodiment according to the present invention. 
       FIG. 50  illustrates various aberrations at a wide-angle end of a second example in the eleventh embodiment according to the present invention. 
       FIG. 51  illustrates various aberrations at a standard position of the second example in the eleventh embodiment according to the present invention. 
       FIG. 52  illustrates various aberrations at a telephoto end of the second example in the eleventh embodiment according to the present invention. 
       FIG. 53  illustrates various aberrations at a wide-angle end of a third example in the eleventh embodiment according to the present invention. 
       FIG. 54  illustrates various aberrations at a standard position of the third example in the eleventh embodiment according to the present invention. 
       FIG. 55  illustrates various aberrations at a telephoto end of the third example in the eleventh embodiment according to the present invention. 
       FIG. 56  is a view showing the arrangement of a zoom lens in a twelfth embodiment according to the present invention. 
       FIG. 57  is a view specifically showing the arrangement of the zoom lens in the twelfth embodiment. 
       FIG. 58  illustrates various aberrations at a wide-angle end in the twelfth embodiment according to the present invention. 
       FIG. 59  illustrates various aberrations at a standard position in the twelfth embodiment according to the present invention. 
       FIG. 60  illustrates various aberrations at a telephoto end in the twelfth embodiment according to the present invention. 
       FIG. 61  is a view showing the arrangement of a zoom lens in a thirteenth embodiment according to the present invention. 
       FIG. 62  illustrates various aberrations at a wide-angle end in the thirteenth embodiment according to the present invention. 
       FIG. 63  illustrates various aberrations at a standard position in the thirteenth embodiment according to the present invention. 
       FIG. 64  illustrates various aberrations at a telephoto end in the thirteenth embodiment according to the present invention. 
       FIG. 65  is a view showing the arrangement of a video camera in a fourteenth embodiment according to the present invention. 
       FIG. 66  is a view showing the arrangement of a zoom lens in a fifteenth embodiment according to the present invention. 
       FIG. 67  illustrates various aberrations at a wide-angle end in the fifteenth embodiment according to the present invention. 
       FIG. 68  is illustrates various aberrations at a standard position in the fifteenth embodiment according to the present invention. 
       FIG. 69  illustrates various aberrations at a telephoto end in the fifteenth embodiment according to the present invention. 
       FIG. 70  is a view showing the arrangement of a zoom lens in a sixteenth embodiment according to the present invention. 
       FIG. 71  illustrates various aberrations at a wide-angle end in the sixteenth embodiment according to the present invention. 
       FIG. 72  illustrates various aberrations at a standard position in the sixteenth embodiment according to the present invention. 
       FIG. 73  illustrates various aberrations at a telephoto end in the sixteenth embodiment according to the present invention. 
       FIG. 74  is a view showing the arrangement of a zoom lens in a seventeenth embodiment according to the present invention. 
       FIG. 75  illustrates various aberrations at a wide-angle end in the seventeenth embodiment according to the present invention. 
       FIG. 76  illustrates various aberrations at a standard position in the seventeenth embodiment according to the present invention. 
       FIG. 77  illustrates various aberrations at a telephoto end in the seventeenth embodiment according to the present invention. 
       FIG. 78  is a view showing the arrangement of a zoom lens in a eighteenth embodiment according to the present invention. 
       FIG. 79  illustrates various aberrations at a wide-angle end in the eighteenth embodiment according to the present invention. 
       FIG. 80  illustrates various aberrations at a standard position in the eighteenth embodiment according to the present invention. 
       FIG. 81  illustrates various aberrations at a telephoto end in the eighteenth embodiment according to the present invention. 
       FIG. 82  is a view showing the arrangement of a zoom lens in a nineteenth embodiment according to the present invention. 
       FIG. 83  illustrates various aberrations at a wide-angle end in the nineteenth embodiment according to the present invention. 
       FIG. 84  illustrates various aberrations at a standard position in the nineteenth embodiment according to the present invention. 
       FIG. 85  illustrates various aberrations at a telephoto end in the nineteenth embodiment according to the present invention. 
       FIG. 86  is a view showing the arrangement of a zoom lens in a twentieth embodiment according to the present invention. 
       FIG. 87  illustrates various aberrations at a wide-angle end in the twentieth embodiment according to the present invention. 
       FIG. 88  illustrates various aberrations at a standard position in the twentieth embodiment according to the present invention. 
       FIG. 89  illustrates various aberrations at a telephoto end in the twentieth embodiment according to the present invention. 
       FIG. 90  is a view showing the arrangement of a zoom lens in a twenty-first embodiment according to the present invention. 
       FIG. 91  illustrates various aberrations at a wide-angle end in the twenty-first embodiment according to the present invention. 
       FIG. 92  illustrates various aberrations at a standard position in the twenty-first embodiment according to the present invention. 
       FIG. 93  illustrates various aberrations at a telephoto end in the twenty-first embodiment according to the present invention. 
       FIG. 94  is a view showing the arrangement of a video camera in a twenty-second embodiment according to the present invention. 
   

   BEST MODE FOR CARRYING OUT THE INVENTION 
   Hereinafter, the present invention will be described by way of illustrative embodiments. 
   First Embodiment 
     FIG. 1  is a view showing the arrangement of a zoom lens in a first embodiment according to the present invention. As shown in  FIG. 1 , a zoom lens has a structure in which a first lens group  11 , a second lens group  12 , a third lens group  13 , and a fourth lens group  14  are disposed from an object side left side in  FIG. 1 ) to an image plane side (right side in  FIG. 1 ) in this order. 
   The first lens group  11  has a positive refracting power, and is fixed with respect to the image plane in varying power and focusing. The second lens group  12  has a negative refracting power and varies power by moving along an optical axis. The third lens group  13  is composed of a single lens having a positive refracting power and is fixed with respect to the image plane in varying power and focusing. 
   When camera shake occurs, shake of an image is corrected by moving the third lens group  13  in a direction vertical to the optical axis. Since camera shake is corrected in this way by moving a lens with smaller diameter, a small and lightweight video camera can be provided. Furthermore, power consumption also can be reduced since a load on the driving system becomes lighter. 
   The fourth lens group  14  has a positive refracting power, moves along an optical axis so as to keep the image plane varied by the shift of the second lens group  12  and the object at a predetermined position from a reference surface, thereby moving an image and adjusting the focus thereof at the same time in accordance with variable power. Since aberration of camera shake can be corrected more efficiently by providing at least one aspherical surface to the lens of the third group  13 , performance in shifting the lenses can be improved. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 1. In Table 1, r is a radius of curvature of a lens (mm), d is a thickness of a lens or air distance (mm) between lenses, n is a refractive index of each lens with respect to a d-line, and v is an Abbe&#39;s number of each lens with respect to the d-line. These also apply to Tables 4, 7, 10, 13, 19, 25, 31, 37, 43, 46, 49, 52, 55, 58, 61, 64, 67, 70, 73, and 76. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 1 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               59.253 
               1.20 
               1.80518 
               25.4 
             
             
                 
               2 
               25.011 
               7.30 
               1.60311 
               60.7 
             
             
                 
               3 
               −142.977 
               0.20 
             
             
                 
               4 
               21.743 
               3.95 
               1.69680 
               55.6 
             
             
                 
               5 
               60.993 
               Variable 
             
             
               2 
               6 
               58.338 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               6.000 
               3.39 
             
             
                 
               8 
               −8.642 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               8.000 
               2.60 
               1.80518 
               25.5 
             
             
                 
               10 
               −85.700 
               Variable 
             
             
               3 
               11 
               13.702 
               3.00 
               1.51450 
               63.1 
             
             
                 
               12 
               −43.933 
               Variable 
             
             
               4 
               13 
               137.583 
               0.80 
               1.84666 
               23.9 
             
             
                 
               14 
               10.422 
               2.80 
               1.60602 
               57.4 
             
             
                 
               15 
               −46.478 
               0.16 
             
             
                 
               16 
               13.885 
               2.60 
               1.56883 
               56.0 
             
             
                 
               17 
               −24.865 
               Variable 
             
             
               6 
               18 
               ∞ 
               4.00 
               1.51633 
               64.1 
             
             
                 
               19 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   Table 2 shows aspherical coefficients in the examples of Table 1. In Table 2, K is a conic constant, and D, E, F, G are aspherical coefficients. These also apply to Tables 5, 8, 11, 14, 26, 32, 38, 44, 47, 50, 53, 56, 59, 62, 65, 68, 71, 74, and 77. 
   
     
       
         
             
             
           
             
                 
               TABLE 2 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               17 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
                2.44209 × 10 −1   
               −2.94965 × 10 −2   
               −7.06772 × 10 
               5.00685 
             
             
               D 
                9.09600 × 10 −5   
               −8.84486 × 10 −5   
               −8.47419 × 10 −5   
               8.59675 × 10 −5   
             
             
               E 
                3.54726 × 10 −6   
               −2.01845 × 10 −7   
                1.51914 × 10 −6   
               3.78258 × 10 −7   
             
             
               F 
               −6.27173 × 10 −7   
                1.11591 × 10 −8   
               −3.20919 × 10 −8   
               4.82992 × 10 −10   
             
             
               G 
                1.82732 × 10 −8   
               −1.53242 × 10 −10   
               −1.00434 × 10 −9   
               1.52605 × 10 −10   
             
             
                 
             
          
         
       
     
   
   The following Table 3 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. The standard position is where the third lens group  13  is placed most closely to the fourth lens group  14 . In Table 3, f(mm), F/NO, and ω(°) represent a focal length, an F number, and an incident half-angle of view at a wide-angle end, a standard position, and a telephoto end of the zoom lens. These also apply to Tables 6, 9, 12, 15, 26, 45, 48, 51, 54, 57, 60, 63, 66, 69, 72, 75, and 78. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 3 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.018 
               23.629 
               64.517 
             
             
                 
               F/NO 
               1.462 
               1.750 
               2.145 
             
             
                 
               2ω 
               65.578 
               11.544 
               4.354 
             
             
                 
               d5 
               0.500 
               16.120 
               20.600 
             
             
                 
               d10 
               22.043 
               5.523 
               1.943 
             
             
                 
               d14 
               9.733 
               5.467 
               9.131 
             
             
                 
               d19 
               1.009 
               5.275 
               1.611 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 2 to 4  show various aberrations at the wide-angle end ( FIG. 2 ), the standard position ( FIG. 3 ), and the telephoto end ( FIG. 4 ) of the zoom lens shown in Table 1. In each figure, (a) shows a spherical aberration, where a solid line represents values with respect to the d-line and a broken line represents sine condition; (b) shows astigmatism, where a solid line represents a curvature of a sagittal image plane, and a broken line represents a curvature of a meridional image plane; (c) shows a distortion aberration; (d) shows a longitudinal chromatic aberration, where a solid line represents values with respect to the d-line, a short broken line represents values with respect to an F-line, and a long broken line represents values with respect to a C-line; and (e) shows a chromatic aberration of magnification, where a short broken line represents values with respect to the F-line, and a long broken line represents values with respect to the C-line. This also applies to  FIGS. 6 to 8 ,  FIGS. 10 to 12 ,  FIGS. 14 to 16 ,  FIGS. 18 to 20 ,  FIGS. 21 to 23 ,  FIGS. 25 to 27 ,  FIGS. 30 to 32 ,  FIGS. 35 to 37 ,  FIGS. 40 to 42 ,  FIGS. 47 to 49 ,  FIGS. 53  to  55 ,  FIGS. 58 to 60 ,  FIGS. 62 to 64 ,  FIGS. 67 to 69 ,  FIGS. 71 to 73 ,  FIGS. 75 to 77 ,  FIGS. 79 to 81 ,  FIGS. 84 to 86 ,  FIGS. 87 to 89 , and  FIGS. 91 to 93 . 
   As is understood from  FIGS. 2 to 4 , the zoom lens in the present example exhibits satisfactory aberration performance. 
   The following expressions (1) and (2) relate to the shifting amount of the correcting lens (the third lens group  13 ).
 
Yt&gt;Y  (1)
 
( Y/Yt )/( f/ft )&lt;1.5  (2)
 
   In the expressions (1) and (2), Y represents the shifting amount of the correcting lens (the third lens group  13 ) at the focal length f of the entire system when correcting camera shake; Yt represents the shifting amount of the correcting lens (the third lens group  13 ) at the telephoto end; and ft represents a focal length at the telephoto end. 
   For a zoom lens, a correcting lens moves further as the zoom ratio is great when the correction angle is constant in the whole zooming region. On the other hand, the correcting lens moves less when the zooming ratio is small. That is, when the shift of the lens exceeds the upper limit defined in the expressions (1) and (2), overcorrection occurs and the optical performance will deteriorate greatly. In conclusion, by satisfying the expressions (1) and (2), a zoom lens having a function to correct camera shake, where the aberration performance deteriorate less even during camera shake, can be obtained. This applies also to the following embodiments. 
   The aspherical shape of the third lens group  13  is defined by the following equation (A), which applies also to the allowing embodiments 2-5. 
   
     
       
         
           
             
               
                 SAG 
                 = 
                 
                   
                     
                       
                         H 
                         2 
                       
                       / 
                       R 
                     
                     
                       1 
                       + 
                       
                         
                           1 
                           - 
                           
                             
                               ( 
                               
                                 1 
                                 + 
                                 K 
                               
                               ) 
                             
                             ⁢ 
                             
                               
                                 ( 
                                 
                                   H 
                                   / 
                                   R 
                                 
                                 ) 
                               
                               2 
                             
                           
                         
                       
                     
                   
                   + 
                   
                     D 
                     · 
                     
                       H 
                       4 
                     
                   
                   + 
                   
                     E 
                     · 
                     
                       H 
                       6 
                     
                   
                   + 
                   
                     F 
                     · 
                     
                       H 
                       8 
                     
                   
                   + 
                   
                     G 
                     · 
                     
                       H 
                       10 
                     
                   
                 
               
             
             
               
                 ( 
                 A 
                 ) 
               
             
           
         
       
     
       
       SAG: a distance from the apex on the aspherical surface to a point on the same aspherical surface having a height H from the optical axis 
       H: a height from an optical axis 
       R is a radius of curvature at the apex on the aspherical surface 
       K: a conical constant 
       D, E, F, G: aspherical coefficients 
     
  
   Second Embodiment 
     FIG. 5  is a view showing the arrangement of a zoom lens in a second embodiment according to the present invention. As shown in  FIG. 5 , a zoom lens has a structure in which a first lens group  51 , a second lens group  52 , a third lens group  53 , and a fourth lens group  64  are disposed from an object side deft side in  FIG. 5 ) to an image plane side (right side in  FIG. 5 ) in this order. Basic structure and operations are the same as the first embodiment. Specific examples of zoom lenses according to this embodiment are shown in the following Table 4. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 4 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               41.544 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               21.097 
               5.00 
               1.58913 
               61.2 
             
             
                 
               3 
               −95.428 
               0.20 
             
             
                 
               4 
               17.473 
               2.70 
               1.60311 
               60.7 
             
             
                 
               5 
               42.181 
               Variable 
             
             
               2 
               6 
               41.372 
               0.65 
               1.77250 
               49.6 
             
             
                 
               7 
               5.857 
               2.89 
             
             
                 
               8 
               −7.776 
               0.85 
               1.66547 
               55.2 
             
             
                 
               9 
               8.195 
               2.05 
               1.84666 
               23.9 
             
             
                 
               10 
               340.000 
               Variable 
             
             
               3 
               11 
               17.024 
               2.00 
               1.68619 
               34.2 
             
             
                 
               12 
               −400.000 
               Variable 
             
             
               4 
               13 
               −27.898 
               0.65 
               1.84666 
               23.9 
             
             
                 
               14 
               18.114 
               2.35 
               1.51450 
               63.1 
             
             
                 
               15 
               −18.114 
               0.10 
             
             
                 
               16 
               18.601 
               3.40 
               1.51450 
               63.1 
             
             
                 
               17 
               −9.892 
               Variable 
             
             
               5 
               18 
               ∞ 
               14.00 
               1.58913 
               61.0 
             
             
               6 
               19 
               ∞ 
               3.90 
               1.51633 
               64.1 
             
             
                 
               20 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   Table 5 shows aspherical coefficients in the examples of Table 4. 
   
     
       
         
             
             
           
             
                 
               TABLE 5 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               15 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −1.10251 × 10 −1   
                8.93500 × 10 −2   
                0.00000 
               −3.79663 × 10 −1   
             
             
               D 
               −7.40852 × 10 −5   
               −8.17245 × 10 −5   
                1.30862 × 10 −5   
                2.87398 × 10 −4   
             
             
               E 
                2.84234 × 10 −5   
               −4.29821 × 10 −6   
               −4.69807 × 10 −6   
                2.61848 × 10 −6   
             
             
               F 
               −4.64719 × 10 −6   
                3.44381 × 10 −7   
                2.94604 × 10 −7   
                1.24341 × 10 −7   
             
             
               G 
                2.04967 × 10 −7   
               −1.18101 × 10 −8   
               −9.69640 × 10 −9   
               −1.73992 × 10 −9   
             
             
                 
             
          
         
       
     
   
   The following Table 6 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 6 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.165 
               24.690 
               49.101 
             
             
                 
               F/NO 
               1.674 
               2.070 
               2.373 
             
             
                 
               2ω 
               59.818 
               10.314 
               5.244 
             
             
                 
               d5 
               0.700 
               13.501 
               16.690 
             
             
                 
               d10 
               18.493 
               5.692 
               2.503 
             
             
                 
               d14 
               5.806 
               1.925 
               4.680 
             
             
                 
               d19 
               1.009 
               4.890 
               2.135 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 6 to 8  show various aberrations at the wide-angle end ( FIG. 6 ), the standard position ( FIG. 7 ), and the telephoto end ( FIG. 8 ) of the zoom lens shown in Table 4. As is understood from  FIGS. 6 to 8 , the zoom lens in the present example exhibits satisfactory aberration performance. 
   By satisfying the expressions (1) and (2), a zoom lens having a function to correct camera shake can be obtained, and the aberration performance deteriorate less during camera shake. 
   Third Embodiment 
     FIG. 9  is a view showing the arrangement of a zoom lens in a third embodiment according to the present invention. As shown in  FIG. 9 , a zoom lens has a structure in which a first lens group  91 , a second lens group  92 , a third lens group  93 , and a fourth lens group  94  are disposed from an object side Deft side in  FIG. 9 ) to an image plane side (right side in  FIG. 9 ) in this order. The first lens group  91  has a positive refracting power and is fixed with respect to the image plane in varying power and focusing. 
   The second lens group  92  has a negative refracting power and varies power by moving along the optical axis. The third lens group  93  is composed of two lenses: one lens having a positive refracting power and one lens having a negative refracting power, and it is fixed with respect to the image plane in varying power and focusing. When camera shake occurs, shake of an image is corrected by moving the whole third lens group  93  in a direction vertical to the optical axis. 
   As mentioned above, by increasing the number of movable lenses, high optical performance can be maintained when the lenses are moved. Since a whole lens group of a united optical performance is decentered, deterioration in aberration can be decreased when compared to a type of zoom lens where a part of lenses in a group is moved. 
   The fourth lens group  94  has a positive refracting power, and it moves along an optical axis so as to keep the image plane varied by a shift of the second lens group  92  and an object at a predetermined position from a reference surface, thereby moving an image and adjusting the fcus thereof at the same time in accordance with variable power. 
   Since the aberration can be corrected during camera shake with greater efficiency by applying at least one aspherical surface to the lenses of the third group  93 , performance during the move of the lenses can be improved. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 7. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 7 
             
             
                 
             
             
               Group 
               Surf 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               48.617 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               24.708 
               4.90 
               1.60311 
               60.7 
             
             
                 
               3 
               −355.522 
               0.15 
             
             
                 
               4 
               24.085 
               2.90 
               1.60311 
               60.7 
             
             
                 
               5 
               74.515 
               Variable 
             
             
               2 
               6 
               73.357 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               5.318 
               3.22 
             
             
                 
               8 
               −10.237 
               0.80 
               1.60602 
               57.5 
             
             
                 
               9 
               7.306 
               2.40 
               1.80518 
               25.4 
             
             
                 
               10 
               −350.000 
               Variable 
             
             
               3 
               11 
               7.997 
               4.45 
               1.60602 
               57.5 
             
             
                 
               12 
               −17.026 
               0.60 
             
             
                 
               13 
               57.521 
               0.70 
               1.80518 
               25.4 
             
             
                 
               14 
               8.270 
               Variable 
             
             
               4 
               15 
               11.387 
               0.70 
               1.68613 
               34.2 
             
             
                 
               16 
               6.389 
               2.60 
               1.60602 
               57.5 
             
             
                 
               17 
               −41.310 
               Variable 
             
             
               5 
               18 
               ∞ 
               3.25 
               1.51633 
               64.0 
             
             
                 
               19 
               ∞ 
             
             
                 
             
          
         
       
     
   
   Table 8 shows aspherical coefficients in the examples of Table 7. 
   
     
       
         
             
             
           
             
                 
               TABLE 8 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               17 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −8.18660 
               −3.87371 × 10 −1   
                7.80366 × 10 −1   
               −7.55214 × 10 +1   
             
             
               D 
               −9.06079 × 10 −4   
               −1.20009 × 10 −4   
                2.87007 × 10 −4   
               −9.87827 × 10 −5   
             
             
               E 
                2.88719 × 10 −5   
                3.93781 × 10 −7   
               −5.40973 × 10 −7   
                3.54330 × 10 −6   
             
             
               F 
               −7.10067 × 10 −7   
                0.00000 
                0.00000 
                0.00000 
             
             
                 
             
          
         
       
     
   
   The following Table 9 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 9 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto-end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.827 
               38.626 
               91.142 
             
             
                 
               F/NO 
               1.677 
               2.509 
               3.407 
             
             
                 
               2ω 
               64.762 
               6.542 
               2.912 
             
             
                 
               d5 
               0.5000 
               21.9344 
               26.2500 
             
             
                 
               d10 
               27.8000 
               6.3655 
               2.0500 
             
             
                 
               d14 
               10.1301 
               2.6424 
               9.3301 
             
             
                 
               d17 
               5.0072 
               12.4949 
               5.8072 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 10 to 12  show various aberrations at the wide-angle end ( FIG. 10 ), the standard position ( FIG. 11 ), and the telephoto end ( FIG. 12 ) of the zoom lens shown in Table 7. As is understood from  FIGS. 10 to 12 , the zoom lens in the present example exhibits satisfactory aberration performance. 
   By satisfying the expressions (1) and (2), a zoom lens having a function to correct camera shake can be obtained, and the aberration performance deteriorates less during camera shake. 
   Fourth Embodiment 
     FIG. 13  is a view showing the arrangement of a zoom lens in a fourth embodiment according to the present invention. As shown in  FIG. 13 , a zoom lens has a structure in which a first lens group  131 , a second lens group  182 , a third lens group  133 , and a fourth lens group  134  are disposed from an object side (left side in  FIG. 13 ) to an image plane side (right side in  FIG. 13 ) in this order. 
   The first lens group  131  has a positive refracting power and is fixed with respect to the image plane even in varying power and focusing. The second lens group  182  has a negative refracting power and varies power by moving along the optical axis. The third lens group  133  is composed of two lenses: one lens having a positive refracting power and one lens having a negative refracting power, and it is fixed with respect to the image plane in varying power and focusing. 
   When camera shake occurs, shake of the image is corrected by moving the whole third lens group  133  in a direction vertical to the optical axis. As mentioned above, by increasing the number of movable lenses; high optical performance can be maintained when the lenses are moved. 
   Since the third lens group  133  in this embodiment is composed of two lenses: one lens having a positive refracting power and one lens having a negative refracting power, aberration can be corrected more efficiently when correcting camera shake, and deterioration in the image quality can be decreased when correcting camera shake. 
   The fourth lens group  134  has a positive refracting power, moves along an optical axis so as to keep the image plane varied by a shift of the second lens group  132  and an object at a predetermined position from a reference surface, thereby moving an image and adjusting the focus thereof at the same time in accordance with variable power. Since the aberration can be corrected when correcting camera shake further efficiently by applying at least one aspherical surface to the lenses of the third group  133 , performance can be improved when the lenses are moved. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 10. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 10 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               41.544 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               21.097 
               5.00 
               1.58913 
               61.2 
             
             
                 
               3 
               −95.428 
               0.20 
             
             
                 
               4 
               17.473 
               2.70 
               1.60311 
               60.7 
             
             
                 
               5 
               42.181 
               Variable 
             
             
               2 
               6 
               41.372 
               0.65 
               1.77250 
               49.6 
             
             
                 
               7 
               5.857 
               2.89 
             
             
                 
               8 
               −7.776 
               0.85 
               1.66547 
               55.2 
             
             
                 
               9 
               8.195 
               2.05 
               1.84666 
               23.9 
             
             
                 
               10 
               340.000 
               Variable 
             
             
               3 
               11 
               14.743 
               2.45 
               1.51450 
               63.1 
             
             
                 
               12 
               −45.960 
               1.50 
             
             
                 
               13 
               33.378 
               1.50 
               1.66547 
               55.2 
             
             
                 
               14 
               19.936 
               Variable 
             
             
               4 
               15 
               −41.230 
               0.65 
               1.84666 
               23.9 
             
             
                 
               16 
               22.061 
               2.20 
               1.51450 
               63.1 
             
             
                 
               17 
               −38.993 
               0.10 
             
             
                 
               18 
               14.246 
               3.40 
               1.51450 
               63.1 
             
             
                 
               19 
               −9.338 
               Variable 
             
             
               5 
               20 
               ∞ 
               14.00 
               1.58913 
               61.0 
             
             
               6 
               22 
               ∞ 
               3.90 
               1.51633 
               64.1 
             
             
                 
               23 
               ∞ 
             
             
                 
             
          
         
       
     
   
   Table 11 shows aspherical coefficients in the Examples of Table 10. 
   
     
       
         
             
             
           
             
                 
               TABLE 11 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               17 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −1.10251 × 10 −1   
                0.00000 
               0.00000 
               −3.79663 × 10 −1   
             
             
               D 
               −7.40852 × 10 −5   
               −1.56773 × 10 −5   
               9.91198 × 10 −5   
                4.04267 × 10 −4   
             
             
               E 
                2.84234 × 10 −5   
                2.64330 × 10 −6   
               4.19737 × 10 −6   
                3.44573 × 10 −6   
             
             
               F 
               −4.64719 × 10 −6   
               −2.20686 × 10 −7   
               2.48747 × 10 −8   
                1.86356 × 10 −7   
             
             
               G 
                2.04967 × 10 −7   
                5.27090 × 10 −10   
               1.70900 × 10 −9   
               −2.73441 × 10 −9   
             
             
                 
             
          
         
       
     
   
   The following Table 12 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 12 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.129 
               24.191 
               49.099 
             
             
                 
               F/NO 
               1.681 
               2.070 
               2.334 
             
             
                 
               2ω 
               60.356 
               10.536 
               5.287 
             
             
                 
               d5 
               0.700 
               13.501 
               16.690 
             
             
                 
               d10 
               16.993 
               4.192 
               1.003 
             
             
                 
               d14 
               5.806 
               1.925 
               4.680 
             
             
                 
               d19 
               1.009 
               4.890 
               2.135 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 14 to 16  show various aberrations at the wide-angle end ( FIG. 14 ), the standard position ( FIG. 15 ), and the telephoto end ( FIG. 16 ) of the zoom lens shown in Table 10. As is shown in  FIGS. 14 to 16 , the zoom lens in the present embodiment exhibits satisfactory aberration performance. 
   By satisfying the expressions (1) and (2), a zoom lens having a function to correct camera shake can be obtained, in which the aberration performance deteriorates less during camera shake. 
   Fifth Embodiment 
     FIG. 17  is a view showing the arrangement of a zoom lens in a fifth embodiment according to the present invention. As shown in  FIG. 17 , a zoom lens has a structure in which a first lens group  171 , a second lens group  172 , a third lens group  173 , and a fourth lens group  174  are disposed from an object side (left side in  FIG. 17 ) to an image plane side (right side in  FIG. 17 ) in this order. 
   The first lens group  171  has a positive refracting power and is fixed with respect to the image plane even in varying power and focusing. The second lens group  172  has a negative refracting power and varies power by moving along the optical axis. 
   The third lens group  173  is composed of three lenses including at least one lens having a positive refracting power and at least one lens having a negative refracting power, and the group is fixed with respect to the image plane in varying power and focusing. 
   When camera shake occurs, shake of the image is corrected by moving the whole third lens group  173  in a direction vertical to the optical axis. For a small zoom lens, the third lens group  173  is required to have a strong positive refracting power to shorten the whole length, and this will cause aberration. 
   However, since the zoom lens in this embodiment has a third lens group  173  composed of three lenses, aberration occurring at the third lens group  173  is suppressed and high optical performance is maintained when the lenses are moved. 
   The fourth lens group  174  has a positive refracting power, and moves along an optical axis so as to keep the image plane varied by a shift of the second lens group  172  and an object at a predetermined position from a reference surface, thereby moving an image and adjusting the focus thereof at the same time in accordance with variable power. 
   Since the aberration can be corrected during camera shae with more efficiency by applying at least one aspherical surface to the lenses of the third group  173 , performance can be improved when the lenses are moved. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 13. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 13 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               48.280 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               17.748 
               4.53 
               1.60311 
               60.7 
             
             
                 
               3 
               −67.680 
               0.20 
             
             
                 
               4 
               14.615 
               2.67 
               1.69680 
               55.6 
             
             
                 
               5 
               42.483 
               Variable 
             
             
               2 
               6 
               42.483 
               0.60 
               1.77250 
               49.6 
             
             
                 
               7 
               4.842 
               2.15 
             
             
                 
               8 
               −6.478 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               5.874 
               1.80 
               1.80518 
               25.5 
             
             
                 
               10 
               −323.142 
               Variable 
             
             
               3 
               11 
               7.889 
               4.55 
               1.66547 
               55.2 
             
             
                 
               12 
               −14.939 
               0.10 
             
             
                 
               13 
               9.748 
               2.40 
               1.51633 
               64.1 
             
             
                 
               14 
               −104.180 
               0.60 
               1.84666 
               23.9 
             
             
                 
               15 
               5.767 
               Variable 
             
             
               4 
               16 
               7.481 
               2.87 
               1.51450 
               63.1 
             
             
                 
               17 
               −31.976 
               Variable 
             
             
               5 
               18 
               ∞ 
               4.30 
               1.51633 
               64.1 
             
             
                 
               19 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   Table 14 shows aspherical coefficients in the Examples of Table 13. 
   
     
       
         
             
             
           
             
                 
               TABLE 14 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               16 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −1.30349 
               −7.99910 
               −6.269020 
               −1.99544 × 10 −2   
             
             
               D 
               −6.01825 × 10 −4   
               −1.39502 × 10 −4   
               −4.75872 × 10 −6   
               −2.07422 × 10 −5   
             
             
               E 
               −2.10812 × 10 −5   
                2.02487 × 10 −7   
                1.65237 × 10 −7   
               −6.99987 × 10 −6   
             
             
               F 
                0.00000 
                0.00000 
                0.00000 
                0.00000 
             
             
               G 
                0.00000 
                0.00000 
                0.00000 
                0.00000 
             
             
                 
             
          
         
       
     
   
   The following Table 15 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 15 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.827 
               21.634 
               46.275 
             
             
                 
               F/NO 
               1.461 
               2.197 
               2.851 
             
             
                 
               2ω 
               59.897 
               12.728 
               6.609 
             
             
                 
               d5 
               0.700 
               9.569 
               12.450 
             
             
                 
               d10 
               13.383 
               4.514 
               1.633 
             
             
                 
               d14 
               6.113 
               1.859 
               6.193 
             
             
                 
               d19 
               1.000 
               5.254 
               0.920 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 18 to 20  show various aberrations at the wide-angle end ( FIG. 18 ), the standard position ( FIG. 19 ), and the telephoto end ( FIG. 20 ) of the zoom lens shown in Table 13. As is shown in  FIGS. 18 to 20 , the zoom lens in the present example exhibits satisfactory aberration performance. 
   By satisfying the expressions (1) and (2), a zoom lens having a function to correct camera shake can be obtained, and the aberration performance deteriorates less during camera shake. 
   Specific examples of zoom lenses according to this embodiment, in addition to the above-mentioned lenses, are shown in the allowing Table 16. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 16 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               31.758 
               0.90 
               1.80518 
               25.5 
             
             
                 
               2 
               15.951 
               4.50 
               1.58913 
               61.2 
             
             
                 
               3 
               −135.286 
               0.15 
             
             
                 
               4 
               14.102 
               3.00 
               1.58913 
               61.2 
             
             
                 
               5 
               45.000 
               Variable 
             
             
               2 
               6 
               45.000 
               0.50 
               1.77250 
               49.6 
             
             
                 
               7 
               4.188 
               2.36 
             
             
                 
               8 
               −6.630 
               0.70 
               1.60602 
               57.8 
             
             
                 
               9 
               5.382 
               1.75 
               1.80518 
               25.5 
             
             
                 
               10 
               88.671 
               Variable 
             
             
               3 
               11 
               6.731 
               3.50 
               1.60602 
               57.8 
             
             
                 
               12 
               −11.394 
               0.50 
             
             
                 
               13 
               12.785 
               1.70 
               1.51633 
               64.1 
             
             
                 
               14 
               −350.000 
               0.50 
               1.84666 
               23.9 
             
             
                 
               15 
               5.875 
               Variable 
             
             
               4 
               16 
               7.945 
               1.95 
               1.51450 
               63.1 
             
             
                 
               17 
               −28.581 
               Variable 
             
             
               5 
               18 
               ∞ 
               3.70 
               1.51633 
               64.1 
             
             
                 
               19 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   Table 17 shows aspherical coefficients in the Examples of Table 16. 
   
     
       
         
             
             
           
             
                 
               TABLE 17 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               16 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −3.79187 
               −1.49571 
               −5.54316 
               −2.04960 
             
             
               D 
               −1.52553 × 10 −3   
                6.24513 × 10 −5   
                9.21711 × 10 −6   
                3.68450 × 10 −4   
             
             
               E 
               −4.26600 × 10 −6   
               −3.45653 × 10 −6   
               −4.27080 × 10 −6   
               −8.68455 × 10 −6   
             
             
               F 
               −1.29623 × 10 −6   
                1.02115 × 10 −7   
                1.47247 × 10 −7   
               −2.70755 × 10 −9   
             
             
                 
             
          
         
       
     
   
   The following Table 18 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 18 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.355 
               23.581 
               48.637 
             
             
                 
               F/NO 
               1.857 
               2.101 
               2.485 
             
             
                 
               2ω 
               57.157 
               10.756 
               5.259 
             
             
                 
               d5 
               0.500 
               10.347 
               12.880 
             
             
                 
               d10 
               14.442 
               4.595 
               2.062 
             
             
                 
               d14 
               7.262 
               2.386 
               5.951 
             
             
                 
               d19 
               1.011 
               5.888 
               2.323 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 21 to 23  show various aberrations at the wide-angle end ( FIG. 21 ), the standard position ( FIG. 22 ), and the telephoto end ( FIG. 23 ) of the zoom lens shown in Table 16. As is understood from  FIGS. 21 to 23 , the zoom lens in the present example exhibits satisfactory aberration performance. 
   By satisfying the expressions (1) and (2), a zoom lens having a function to correct camera shake can be obtained, and the aberration performance deteriorates less during camera shake. 
   The first to fifth embodiments relate to zoom lenses. By using these zoom lenses, video cameras having a function to correct camera shake can be provided, and such video cameras can be downsized and lightweight. 
   Sixth Embodiment 
     FIG. 24  is a view showing the arrangement of a zoom lens in a sixth embodiment according to the present invention. As shown in  FIG. 24 , a zoom lens has a structure in which a first lens group  241 , a second lens group  242 , a third lens group  243 , a fourth lens group  244 , and a plate  245  equivalent to an optical low-pass filter and a face plate of a CCD are disposed from an object side to an image plane side in this order. 
   The first lens group  241  has a positive refracting power, and is fixed with respect to the image plane  246  in varying power and focusing. The second lens group  242  has a negative refracting power as a whole and varies power by moving along an optical axis. The third lens group  243  is composed of three lenses: a positive lens, a positive lens, and a negative lens disposed from the object side in this order, and is fixed with respect to the image plane  246  in varying power and focusing. The fourth lens group  244  is composed of one positive lens. The fourth lens group  244  moves along an optical axis  80  as to move an image and adjust the focus thereof at the same time in accordance with variable power. 
   When camera shake occurs, shake of an image is corrected by moving the third lens group  243  vertically with respect to the optical axis direction. Since the third lens group  243  is smaller in lens diameter than the first lens group  241 , correction by moving the third lens group  243  will cause less load for the driving system, and electric power also can be saved. By satisfying the expressions (1) and (2), a zoom lens having a function to correct camera shake, where the aberration performance deteriorates less during camera shake, can be obtained. 
   The following expression (3) relates to a shift of a third lens group.
 
2.0&lt; f 3/ fw&lt; 4.0  (3)
 
   In the above expression (3), f 3  represents a focal length of the third lens group and fw represents a focal length of the entire system at a wide-angle end. 
   When the value falls below the lower limit, the aberration will be difficult to correct in a stationary state or when correcting camera shake even if the third lens group is composed of three lenses. When the value exceeds the upper limit, the shifting amount is increased when correcting camera shake and the zoom lens barrel becomes large in diameter. Moreover, the entire length is increased and the zoom lens cannot be downsized. By satisfying the expression (3), the shifting amount when correcting camera shake can be decreased and the whole length of the zoom lens can be shortened, and thus, a small zoom lens can be provided. 
   Furthermore, by applying at least one aspherical surface to the third lens group as a shift lens group and also to the fourth lens group having focusing action, aberration can be corrected when correcting camera shake as well as in the stationary state. 
   The following expression (4) relates to an aspherical shape of the object side of a lens of the third lens group, when the lens is disposed closest to the object.
 
1.05&lt; R 11/ R 10&lt;2.5  (4)
 
   In the expression (4), R 10  represents a local radius of curvature in the vicinity of the optical axis, and R 11  represents a local radius of curvature in an outer peripheral portion. 
   The expression (4) defines a range to correct the spherical aberration satisfactorily. A negative spherical aberration occurs when the value falls below the lower limit, while positive spherical aberration occurs as a result of overcorrection when the value exceeds the upper limit. 
   The following expression (5) relates to an aspherical shape of a lens of the fourth lens group when viewed from the object side.
 
1.05&lt;R21&lt;R20&lt;2.0  (5)
 
   R 20  represents a local radius of curvature in the vicinity of the optical axis, and R 21  represents a local radius of curvature in an outer peripheral portion. 
   The expression (5) defines a range to satisfactorily correct a coma aberration of an upper flux of an off-axis ray. An internal coma occurs when the value falls below the lower limit, while an external coma occurs when the value exceeds the upper limit. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 19. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 19 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               31.089 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               15.820 
               4.50 
               1.58913 
               61.2 
             
             
                 
               3 
               −171.154 
               0.15 
             
             
                 
               4 
               14.460 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               48.740 
               Variable 
             
             
               2 
               6 
               48.740 
               0.50 
               1.77250 
               49.6 
             
             
                 
               7 
               4.206 
               2.34 
             
             
                 
               8 
               −8.647 
               0.55 
               1.60602 
               57.4 
             
             
                 
               9 
               5.292 
               1.75 
               1.80518 
               25.4 
             
             
                 
               10 
               88.671 
               Variable 
             
             
               3 
               11 
               7.268 
               3.25 
               1.51450 
               63.1 
             
             
                 
               12 
               −14.052 
               0.10 
             
             
                 
               13 
               9.072 
               2.20 
               1.51895 
               57.3 
             
             
                 
               14 
               −37.099 
               0.50 
             
             
                 
               15 
               60.905 
               0.50 
               1.84666 
               25.4 
             
             
                 
               16 
               5.422 
               Variable 
             
             
               4 
               17 
               7.232 
               2.00 
               1.51450 
               63.1 
             
             
                 
               18 
               −42.485 
               Variable 
             
             
               5 
               19 
               ∞ 
               3.70 
               1.51633 
               64.1 
             
             
                 
               20 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The aspherical shape is defined by the following equation CB). (This also applies to examples 7 to 9.) 
   
     
       
         
           
             
               
                 SAG 
                 = 
                 
                   
                     
                       
                         H 
                         2 
                       
                       / 
                       R 
                     
                     
                       1 
                       + 
                       
                         
                           1 
                           - 
                           
                             
                               ( 
                               
                                 1 
                                 + 
                                 K 
                               
                               ) 
                             
                             ⁢ 
                             
                               ( 
                               
                                 H 
                                 / 
                                 
                                   R 
                                   2 
                                 
                               
                               ) 
                             
                           
                         
                       
                     
                   
                   + 
                   
                     D 
                     · 
                     
                       H 
                       4 
                     
                   
                   + 
                   
                     E 
                     · 
                     
                       H 
                       6 
                     
                   
                   + 
                   
                     F 
                     · 
                     
                       H 
                       8 
                     
                   
                 
               
             
             
               
                 ( 
                 B 
                 ) 
               
             
           
         
       
     
       
       SAG: a distance from the apex on the aspherical surface to a point on the same aspherical surface having a height H from the optical axis 
       H: a height from an optical axis 
       R: a radius of curvature at the apex on the aspherical surface 
       K: a conical constant 
       D, E, F: aspherical coefficients 
     
  
   The following Table 20 shows aspherical shapes of the zoom lens in the the present example. 
   
     
       
         
             
             
           
             
                 
               TABLE 20 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               17 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −3.46709 
               −1.57334 
               −4.56016 
               −1.39803 
             
             
               D 
               −1.36790 × 10 −3   
               −6.68922 × 10 −5   
                1.39115 × 10 −5   
                1.90786 × 10 −4   
             
             
               E 
               −1.82278 × 10 −5   
               −1.31623 × 10 −6   
               −1.82005 × 10 −6   
                9.90799 × 10 −6   
             
             
               F 
               −5.96614 × 10 −7   
                8.53637 × 10 −8   
                1.00886 × 10 −7   
               −6.93646 × 10 −7   
             
             
                 
             
          
         
       
     
   
   The following Table 21 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. A standard position represents a position where the third lens group  243  is disposed the closest to the fourth lens group  244 . The Table 21 indicates also a shifting amount Y of the third lens group at a correction of 0.5 degrees. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 21 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               f 
               4.350 
               23.464 
               48.623 
             
             
               F/NO 
               1.873 
               2.096 
               2.490 
             
             
               ω 
               28.770 
               5.415 
               2.638 
             
             
               d5 
               0.500 
               10.344 
               12.893 
             
             
               d10 
               14.442 
               4.597 
               2.049 
             
             
               d16 
               7.262 
               2.393 
               5.880 
             
             
               d18 
               1.012 
               5.880 
               2.393 
             
             
               Y 
               0.034 
               0.197 
               0.392 
             
             
               Expression (2) 
               0.972 
               1.041 
               1.000 
             
             
                 
             
          
         
       
     
   
   As shown in  FIG. 21 , the a shift of the third lens group in this embodiment satisfies the expressions (1) and (2), and thus, it realizes optical performance with less deterioration when compared to a stationary state. 
   Furthermore, in the zoom lens of the present example, a focal length f 3  of the third lens group satisfies the expression (3) and a small zoom lens is provided. 
   
     
       
         
             
             
             
           
             
               TABLE 22 
             
             
                 
             
             
               Fw 
               f3 
               Expression (3) (f3/fw) 
             
             
                 
             
           
          
             
               4.350 
               11.311 
               2.60 
             
             
                 
             
          
         
       
     
   
   In this embodiment, the third lens group has a lens at the side closest to the object, and the both surfaces of the lens are aspherical Especially, the local radius of curvature R 10  in the vicinity of the object-side surface and the local radius of curvature R 11  in an outer peripheral portion have values shown in the following Table 23, and satisfy the expression (4). As a result, the embodiment realizes excellent aberration performance not only in the stationary state but when correcting camera shake, and especially, the embodiment realizes a spherical aberration that is satisfactorily corrected. 
   
     
       
         
             
             
             
           
             
               TABLE 23 
             
             
                 
             
             
               R10 
               R11 
               Expression (4) (R11/R10) 
             
             
                 
             
           
          
             
               7.268 
               13.516 
               1.86 
             
             
                 
             
          
         
       
     
   
   Furthermore, the lens of the fourth lens group has an aspherical surface when viewed from the object side, a local radius of curvature R 20  in the vicinity of an optical axis and a local radius of curvature R 11  in an outer peripheral portion with the values shown in Table 24. Moreover, when the expression (5) is satisfied, excellent aberration performance is realized not only in its station state but when correcting camera shake. Especially a satisfactory coma aberration is realized. 
   
     
       
         
             
             
             
           
             
               TABLE 24 
             
             
                 
             
             
               R20 
               R21 
               Expression (5) (R21/R20) 
             
             
                 
             
           
          
             
               7.232 
               10.112 
               1.40 
             
             
                 
             
          
         
       
     
   
     FIGS. 25 to 27  show various aberrations at the wide-angle end, the standard position, and the telephoto end of the zoom lens shown in Table 19. 
     FIG. 28  shows aberrations at a telephoto end at a correction of 0.5 degrees.  FIGS. 28(   a ),  28 ( b ) and  28 ( c ) show lateral aberrations at a relative angle of view of 0.75, along the axis, and at a relative angle of view of −0.75. A solid line, the dotted line and the wave line represent values with respect to the d-line, F-line and C-line (this applies to the following  FIGS. 33 ,  38 , and  43 ). As indicated in  FIGS. 25-28 , a zoom lens according to this embodiment provides a satisfactory aberration performance. 
   Seventh Embodiment 
     FIG. 29  is a view showing the arrangement of a zoom lens in a seventh embodiment according to the present invention. As shown in  FIG. 29 , a zoom lens has a structure in which a first lens group  61 , a second lens group  62 , a third lens group  63 , a fourth lens group  64 , and a plate  65  equivalent to an optical low-pass filter and a face plate of a CCD are disposed from an object side to an image plane side in this order. 
   The first lens group  61  has a positive refracting power, and is fixed with respect to the image plane  66  in varying power and focusing. The second lens group  62  has a negative refracting power and varies power by moving along an optical axis. The third lens group  63  is composed of three lenses: a positive lens, a positive lens, and a negative lens disposed from the object side in this order, and two of the lenses at the image plane side compose a cemented lens of a positive lens and a negative lens. The third lens group  63  is fixed with respect to the image plane  66  in varying power and focusing. The fourth lens group  64  is composed of one positive lens. The fourth lens group  64  moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. 
   When camera shake occurs, shake of an image is corrected by moving the third lens group  63  vertically with respect to the optical axis direction. Since the third lens group  63  is smaller in lens diameter than the first lens group  61 , correction by moving the third lens group  63  will cause less load for the driving system, and electric power also can be saved. It is preferable that the expressions (1) to (5) are satisfied as in the sixth embodiment. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 25. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 25 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               31.758 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               15.951 
               4.50 
               1.58913 
               61.2 
             
             
                 
               3 
               −135.286 
               0.15 
             
             
                 
               4 
               14.102 
               3.00 
               1.58913 
               61.2 
             
             
                 
               5 
               45.000 
               Variable 
             
             
               2 
               6 
               45.000 
               0.50 
               1.77250 
               49.6 
             
             
                 
               7 
               4.188 
               2.36 
             
             
                 
               8 
               −6.630 
               0.70 
               1.60602 
               57.4 
             
             
                 
               9 
               5.382 
               1.75 
               1.80518 
               25.4 
             
             
                 
               10 
               88.671 
               Variable 
             
             
               3 
               11 
               6.731 
               3.50 
               1.60602 
               57.4 
             
             
                 
               12 
               −11.394 
               0.50 
             
             
                 
               13 
               12.785 
               1.70 
               1.51633 
               54.1 
             
             
                 
               14 
               −350.000 
               0.50 
               1.84666 
               25.4 
             
             
                 
               15 
               5.875 
               Variable 
             
             
               4 
               16 
               7.945 
               1.95 
               1.51450 
               63.1 
             
             
                 
               17 
               −28.581 
               Variable 
             
             
               5 
               18 
               ∞ 
               3.70 
               1.51633 
               64.1 
             
             
                 
               19 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 26 shows aspherical shapes of the zoom lens in the present example. 
   
     
       
         
             
             
           
             
                 
               TABLE 26 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               16 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −3.79187 
               −1.49571 
               −5.54316 
               −2.04960 
             
             
               D 
               −1.52553 × 10 −3   
                6.24513 × 10 −5   
                9.21711 × 10 −6   
                3.68450 × 10 −4   
             
             
               E 
               −4.26600 × 10 −6   
               −3.45653 × 10 −6   
               −4.27080 × 10 −6   
               −8.68455 × 10 −6   
             
             
               F 
               −1.29623 × 10 −6   
                1.02115 × 10 −7   
                1.47247 × 10 −7   
               −2.70755 × 10 −9   
             
             
                 
             
          
         
       
     
   
   The following Table 27 shows zooming distance and shifting amount. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 27 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               f 
               4.355 
               23.464 
               48.623 
             
             
               F/NO 
               1.857 
               2.096 
               2.490 
             
             
               ω 
               28.579 
               5.415 
               2.638 
             
             
               d5 
               0.500 
               10.344 
               12.893 
             
             
               d10 
               14.415 
               4.597 
               2.049 
             
             
               d15 
               7.262 
               2.393 
               5.880 
             
             
               d17 
               1.012 
               5.880 
               2.393 
             
             
               Y 
               0.034 
               0.195 
               0.392 
             
             
               Expression (2) 
               0.970 
               1.027 
               1.000 
             
             
                 
             
          
         
       
     
   
   As shown in Table 27, a shift of the third lens group satisfies the expressions (1) and (2), and it achieves optical performance with less deterioration when compared to a stationary state. 
   As shown in the following Table 28, the focal length f 3  of the third lens group satisfies the expression (3), and thus, a small zoom lens is realized. 
   
     
       
         
             
             
             
           
             
               TABLE 28 
             
             
                 
             
             
               fw 
               f3 
               Expression (3) (f3/fw) 
             
             
                 
             
           
          
             
               4.350 
               11.317 
               2.60 
             
             
                 
             
          
         
       
     
   
   In this embodiment, a lens of the third group, which is positioned closest to the object, has aspherical surfaces on both sides. Especially, the local radius of curvature R 10  in the vicinity of the object side and the local radius of curvature R 11  in an outer peripheral portion have values shown in the following Table 29, and satisfy the expression (4). As a result, the embodiment achieves excellent aberration performance not only in a stationary state but when correcting camera shake, and especially, aspherical aberration is corrected satisfactorily. 
   
     
       
         
             
             
             
           
             
               TABLE 29 
             
             
                 
             
             
               R10 
               R11 
               Expression (4) (R11/R10) 
             
             
                 
             
           
          
             
               6.731 
               12.417 
               1.85 
             
             
                 
             
          
         
       
     
   
   Furthermore, the object-side surface of a lens of the fourth group is aspherical, a local radius of curvature R 20  in the vicinity of an optical axis and a local radius of curvature R 11  in an outer peripheral portion have the values shown in Table 30. Moreover, the expression (5) satisfied, excellent aberration performance is realized not only in its stationary state but at correcting. Especially a satisfactory coma aberration is realized. 
   
     
       
         
             
             
             
           
             
               TABLE 30 
             
             
                 
             
             
               R20 
               R21 
               Expression (5) (R21/R20) 
             
             
                 
             
           
          
             
               7.945 
               11.021 
               1.39 
             
             
                 
             
          
         
       
     
   
     FIGS. 30 to 32  show various aberrations at the wide-angle end, the standard position, and the telephoto end of the zoom lens shown in Table 25.  FIG. 33  shows an aberration at a telephoto end at a correction of 0.5 degrees. As indicated in  FIGS. 30-33 , a zoom lens according to this embodiment provides a satisfactory aberration performance. 
   Eighth Embodiment 
     FIG. 34  is a view showing the arrangement of a zoom lens in an eighth embodiment according to the present invention. As shown in  FIG. 34 , a zoom lens has a structure in which a first lens group  111 , a second lens group  112 , a third lens group  113 , a fourth lens group  114 , and a plate  115  equivalent to an optical low-pass filter and a face plate of a CCD are disposed from an object side to an image plane side in this order. 
   The first lens group  111  has a positive refracting power, and is fixed with respect to the image plane  116  in varying power and focusing. The second lens group  112  has a negative refracting power and varies power by moving along an optical axis. 
   The third lens group  113  is composed of three lenses: a positive lens, a negative lens, and a positive lens disposed from the object side in this order, and is fixed with respect to the image plane  306  in varying power and focusing. The fourth lens group  114  is composed of one positive lens, and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. 
   When camera shake occurs, shake of an image is corrected by moving the third lens group  113  vertically with respect to the optical axis direction. Since the third lens group  113  is smaller in lens diameter than the first lens group  111 , correction by moving the third lens group  113  will cause less load for the driving system, and electric power also can be saved. It is preferable that the expressions (1) to (5) are satisfied as in the sixth embodiment. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 31. The first and second lens groups in these embodiments are the same as shown in Table 19. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 31 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               3 
               11 
               6.854 
               3.95 
               1.51450 
               63.1 
             
             
                 
               12 
               −7.934 
               1.20 
             
             
                 
               13 
               −10.797 
               0.50 
               1.78472 
               25.7 
             
             
                 
               14 
               16.985 
               0.86 
             
             
                 
               15 
               −21.096 
               2.00 
               1.51895 
               57.3 
             
             
                 
               16 
               −6.963 
               Variable 
             
             
               4 
               17 
               9.141 
               1.90 
               1.51450 
               63.1 
             
             
                 
               18 
               335.606 
               Variable 
             
             
               5 
               19 
               ∞ 
               3.70 
               1.51633 
               64.1 
             
             
                 
               20 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 32 shows aspherical shapes of the zoom lens in the present example. 
   
     
       
         
             
             
           
             
                 
               TABLE 32 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               17 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −3.46709 
               −1.99011 
               −3.12036 
               −1.04888 
             
             
               D 
               −1.36790 × 10 −3   
                2.73697 × 10 −4   
                2.30462 × 10 −5   
                1.27223 × 10 −4   
             
             
               E 
               −1.82278 × 10 −5   
               −2.65163 × 10 −6   
                1.73552 × 10 −6   
               −1.69913 × 10 −7   
             
             
               F 
               −5.96614 × 10 −7   
                2.37367 × 10 −7   
                1.42772 × 10 −7   
               −4.55207 × 10 −8   
             
             
                 
             
          
         
       
     
   
   The following Table 33 shows zooming distance and shifting amount. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 33 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               f 
               4.246 
               21.577 
               47.769 
             
             
               F/NO 
               1.859 
               2.003 
               2.426 
             
             
               ω 
               29.455 
               5.923 
               2.694 
             
             
               d5 
               0.500 
               10.344 
               12.893 
             
             
               d10 
               14.442 
               4.597 
               2.049 
             
             
               d15 
               7.261 
               2.300 
               5.779 
             
             
               d17 
               1.013 
               5.973 
               2.495 
             
             
               Y 
               0.031 
               0.161 
               0.347 
             
             
               Expression (2) 
               1.012 
               1.027 
               1.000 
             
             
                 
             
          
         
       
     
   
   As shown in Table 33, a shift of the third lens group satisfies the expressions (1) and (2), and it provides an optical performance with less deterioration when compared to a stationary state. 
   As shown in the following Table 34, the focal length f 3  of the third lens group satisfies the expression (3), and achieves a small zoom lens. 
   
     
       
         
             
             
             
           
             
               TABLE 34 
             
             
                 
             
             
               fw 
               F3 
               Expression (3) (f3/fw) 
             
             
                 
             
           
          
             
               4.246 
               13.079 
               3.08 
             
             
                 
             
          
         
       
     
   
   In this example, a lens of the third group, which is positioned closest to the object, has aspherical surfaces on both sides. Especially, the local radius of curvature R 10  in the vicinity of the object-side and the local radius of curvature R 11  in an outer peripheral portion have values shown in the following Table 35, and satisfy the expression (4). As a result; the embodiment realizes excellent aberration performance not only in a stationary state but when correcting camera shake, and especially, aspherical aberration is corrected satisfactorily. 
   
     
       
         
             
             
             
           
             
               TABLE 35 
             
             
                 
             
             
               R10 
               R11 
               Expression (4) (R11/R10) 
             
             
                 
             
           
          
             
               6.854 
               8.352 
               1.22 
             
             
                 
             
          
         
       
     
   
   Furthermore, the object-side surface of a lens of the fourth group is aspherical, a local radius of curvature R 20  in the vicinity of an optical axis and a local radius of curvature R 11  in an outer peripheral portion have the values shown in Table 36. Moreover, the expression (5) is satisfied, excellent aberration performance is realized not only in its stationary state but when correcting camera shake. Especially a satisfactory coma aberration is achieved. 
   
     
       
         
             
             
             
           
             
               TABLE 36 
             
             
                 
             
             
               R20 
               R21 
               Expression (5) (R21/R20) 
             
             
                 
             
           
          
             
               9.141 
               10.416 
               1.14 
             
             
                 
             
          
         
       
     
   
     FIGS. 85 to 87  show various aberrations at the wide-angle end, the standard position, and the telephoto end of the zoom lens shown in Table 31.  FIG. 38  shows an aberration at a telephoto end at a correction of 0.5 degrees. As indicated in  FIGS. 35-38 , a zoom lens according to this embodiment provides a satisfactory aberration performance. 
   Ninth Embodiment 
     FIG. 39  is a view showing the arrangement of a zoom lens in a ninth embodiment according to the present invention. As shown in  FIG. 39 , a zoom lens has a structure in which a first lens group  161 , a second lens group  162 , a third lens group  163 , a fourth lens group  164 , and a plate  165  equivalent to an optical low-pass filter and a face plate of a CCD are disposed from an object side to an image plane side in this order. 
   The first lens group  161  has a positive refracting power, and is fixed with respect to the image plane  166  in varying power and focusing. The second lens group  162  has a negative refracting power and varies power by moving along an optical axis. The third lens group  163  is composed of three lenses: a positive lens, a negative lens, and a positive lens disposed from the object side in this order, and two of the lenses at the image plane side compose a cemented lens of a negative lens and a positive lens. 
   The third lens group  163  is fixed with respect to the image plane  166  in varying power and focusing. The fourth lens group  164  is composed of one positive lens. The fourth lens group  164  moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. 
   When camera shake occurs, shake of an image is corrected by moving the third lens group  163  vertically with respect to the optical axis direction. Since the third lens group  163  is smaller in lens diameter than the first lens group  161 , correction by moving the third lens group  163  will cause less load for the driving system, and electric power also can be saved. 
   It is preferable that the expressions (1) to (5) are satisfied as in the sixth to eighth embodiments. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 37. The first and second lens groups in this embodiment are the same as shown in Table 19. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 37 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               3 
               11 
               9.762 
               3.00 
               1.51450 
               63.1 
             
             
                 
               12 
               −11.531 
               1.20 
             
             
                 
               13 
               13.057 
               0.50 
               1.75520 
               27.5 
             
             
                 
               14 
               −8.967 
               3.10 
               1.53358 
               51.6 
             
             
                 
               15 
               −6.963 
               Variable 
             
             
               4 
               16 
               15.087 
               1.80 
               1.51450 
               63.1 
             
             
                 
               17 
               −51.013 
               Variable 
             
             
               5 
               18 
               ∞ 
               3.70 
               1.51633 
               64.1 
             
             
                 
               19 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 38 shows aspherical coefficients of the zoom lens in the present example. 
   
     
       
         
             
             
           
             
                 
               TABLE 38 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               17 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −3.46709 
               −3.79890 
               −1.61290 
               −2.22934 
             
             
               D 
               −1.36790 × 10 −3   
                1.01179 × 10 −4   
                4.06410 × 10 −5   
               −1.33735 × 10 −5   
             
             
               E 
               −1.82278 × 10 −5   
               −6.62306 × 10 −7   
                8.30510 × 10 −7   
                1.01922 × 10 −6   
             
             
               F 
               −5.96614 × 10 −7   
                1.67378 × 10 −7   
                1.66830 × 10 −7   
                3.34079 × 10 −8   
             
             
                 
             
          
         
       
     
   
   The following Table 39 shows zooming distance and shifting amount. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 39 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
          
             
               f 
               4.224 
               22.092 
               47.644 
             
             
               F/NO 
               1.823 
               2.112 
               2.441 
             
             
               ω 
               29.569 
               5.749 
               2.672 
             
             
               d5 
               0.500 
               10.344 
               12.893 
             
             
               d10 
               14.442 
               4.597 
               2.049 
             
             
               d15 
               7.260 
               1.815 
               5.657 
             
             
               d17 
               1.014 
               6.459 
               2.617 
             
             
               Y 
               0.030 
               0.150 
               0.332 
             
             
               Expression (2) 
               1.016 
               0.974 
               1.000 
             
             
                 
             
          
         
       
     
   
   As shown in Table 39, the shifting amount of the third lens group satisfies the expressions (1) and (2), and thus, the optical performance deteriorates less when compared to a stationary state. 
   As shown in the following Table 40, the focal length f 3  of the third lens group satisfies the expression (3), and thus, a small zoom lens is achieved. 
   
     
       
         
             
             
             
           
             
               TABLE 40 
             
             
                 
             
             
               Fw 
               f3 
               Expression (3) (f3/fw) 
             
             
                 
             
           
          
             
               4.224 
               13.100 
               3.10 
             
             
                 
             
          
         
       
     
   
   In this embodiment, a lens of the third group, which is disposed closest to the object, has aspherical surfaces at both sides. Especially, the local radius of curvature R 10  in the vicinity of an optical axis at the object-side and the local radius of curvature R 11  in an outer peripheral portion have values shown in the following Table 41, and satisfy the expression (4). As a result, the embodiment realizes excellent aberration performance not only in the stationary state but when correcting camera shake, and especially, aspherical aberration is corrected satisfactorily. 
   
     
       
         
             
             
             
           
             
               TABLE 41 
             
             
                 
             
             
               R10 
               R11 
               Expression (4) (R11/R10) 
             
             
                 
             
           
          
             
               9.762 
               10.339 
               1.06 
             
             
                 
             
          
         
       
     
   
   Furthermore, the object-side surface of a lens included in the fourth lens group is aspherical, a local radius of curvature R 20  in the vicinity of an optical axis and a local radius of curvature R 21  in an outer peripheral portion have the values shown in Table 42. Moreover, the expression (5) is satisfied, and excellent aberration performance is realized not only in its stationary state but when correcting camera shake. Especially, a satisfactory coma aberration is achieved. 
   
     
       
         
             
             
             
           
             
               TABLE 42 
             
             
                 
             
             
               R20 
               R21 
               Expression (5) (R21/R20) 
             
             
                 
             
           
          
             
               15.087 
               16.164 
               1.07 
             
             
                 
             
          
         
       
     
   
     FIGS. 40 to 42  show various aberrations at the wide-angle end, the standard position, and the telephoto end of the zoom lens shown in Table 37.  FIG. 43  shows an aberration at a telephoto end at a correction of 0.5 degrees. 
   As indicated in  FIGS. 40-43 , a zoom lens according to this embodiment provides satisfactory aberration performance. 
   Tenth Embodiment 
     FIG. 44  shows a video camera in one embodiment of the present invention. The video camera is composed of a first lens group of a zoom lens shown in the sixth to ninth embodiments, a second lens group  211 , a third lens group  212 , a fourth lens group  213 , an imager  214 , a signal processing circuit  215 , a camera-shake detecting system  216 , and a driving system  217  for correcting camera shake. As a result, a small video camera having an excellent function for correcting camera shake can be provided. 
   Eleventh Embodiment 
     FIG. 45  is a view to show a basic structure of a zoom lens having a function for correcting camera shake in an eleventh embodiment. As shown in  FIG. 46 , a zoom lens in this embodiment comprises a first lens group having a positive refracting power and being fixed with respect to an image plane; a second lens group having a negative refracting power and varying power by moving along an optical axis; a third lens group having a positive refracting power and being fixed with respect to the image plane; a fourth lens group having a negative refracting power and being fixed with respect to the image plane; and a fifth lens group having a positive refracting power and moving along an optical axis so as to keep the image plane varied by the a shift of the second lens group and an object at a predetermined position from a reference surface, and the elements are disposed from an object side (left side in  FIG. 45 ) to an image plane side (right side in  FIG. 45 ) in this order. When camera shake occurs, shake of an image is corrected by shifting the third lens group having a positive refracting power in a direction vertical to the optical axis. 
     FIG. 46  shows a zoom lens having basic elements as shown in  FIG. 45 . The zoom lens has a structure in which a first lens group  461 , a second lens group  462 , a third lens group  468 , a fourth lens group  464 , and a fifth lens group  465  are disposed from an object side to an image plane side in this order. 
   The first lens group  461  has a positive refracting power, and is fixed with respect to the image plane in varying power and focusing. The second lens group  462  has a negative refracting power and varies power by moving along an optical axis. The third lens group  463  is composed of a positive lens and a negative lens, and has a positive refracting power as a whole. 
   The fourth lens group  464  is composed of a negative lens and a positive lens, and has a negative refracting power as a whole. It is fixed with respect to the image plane in varying power and focusing. The fifth lens group  465  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occur, shake of an image is corrected by moving the third lens group  463  vertically with respect to the optical axis. 
   As described in this embodiment, the third lens group  463  having a positive refracting power and the fourth lens group  464  having a negative refracting power are combined in order to decrease the shifting amount of the shift lens group when correcting camera shake, and to extend the back focus. Especially a long back focus is easy to obtain since a lens group having a negative refracting power is disposed at the image plane side. 
   Moreover, the performance when shifting the lenses can be improved, and downsizing and high performance are obtainable by applying at least one aspherical surface to any of the lenses of the third group. 
   It is preferable that the following expressions (6) and (7) are satisfied when v31 is Abbe&#39;s number of one lens of the third lens group, and v32 is Abbe&#39;s number of the remaining lens of the third group; v41 is Abbe&#39;s number of one lens of the fourth lens group, and v42 is Abbe&#39;s number of the remaining lens of the fourth group.
 
|v31-v32|&gt;25  (6)
 
|v41-v42|&gt;25  (7)
 
   When the expressions (6) and (7) are satisfied, deterioration in chromatic aberration of magnification when correcting camera shake can be reduced. Chromatic aberration of magnification occurs when correcting camera shake due to lens-shifting, however, deterioration of the chromatic aberration of magnification can be reduced even when shifting a lens since a sufficient effect is obtainable for achromatism by setting differences in the Abbe&#39;s number as mentioned above for the respective lens groups. 
   It is preferable that the following expression (8) is satisfied when the lens for correcting camera shake has an aspherical surface at the object side, and rS 1  is a local radius of curvature for a diameter occupying 10% of lens effective diameter, and rS 9  is a local radius of curvature for a diameter occupying 90% of lens effective diameter.
 
0.01&lt; rS 1/ rS 9&lt;2.00  (8)
 
   The expression (8) is a conditional expression to determine the aspherical amount, and it indicates a condition to obtain sufficient aberration performance to realize high resolution for a zoom lens. When the value exceeds the upper limit in the Expression (8), the correcting amount for the spherical aberration is excessively decreased. Moreover, coma flares will occur easily when moving the lens. When the value falls below the lower limit, correction amount of the spherical aberration is excessively increased, and sufficient aberration performance cannot be obtained. Here, the local radius of curvature C is obtainable through an algebraic calculation based on aspherical coefficients figured out from the sag amount of the plane shape. It is obtainable by the following equations (C) and (D). 
   
     
       
         
           
             
               
                 SAG 
                 = 
                 
                   
                     
                       
                         H 
                         2 
                       
                       / 
                       R 
                     
                     
                       1 
                       + 
                       
                         
                           1 
                           - 
                           
                             
                               ( 
                               
                                 1 
                                 + 
                                 K 
                               
                               ) 
                             
                             ⁢ 
                             
                               
                                 ( 
                                 
                                   H 
                                   / 
                                   R 
                                 
                                 ) 
                               
                               2 
                             
                           
                         
                       
                     
                   
                   + 
                   
                     D 
                     · 
                     
                       H 
                       4 
                     
                   
                   + 
                   
                     E 
                     · 
                     
                       H 
                       6 
                     
                   
                   + 
                   
                     F 
                     · 
                     
                       H 
                       8 
                     
                   
                   + 
                   
                     G 
                     · 
                     
                       H 
                       10 
                     
                   
                 
               
             
             
               
                 ( 
                 C 
                 ) 
               
             
           
           
             
               
                 
                     
                 
                 ⁢ 
                 
                   C 
                   = 
                   
                     
                       
                         ( 
                         
                           1 
                           + 
                           
                             
                               ( 
                               
                                 
                                   ⅆ 
                                   SAG 
                                 
                                 
                                   ⅆ 
                                   H 
                                 
                               
                               ) 
                             
                             2 
                           
                         
                         ) 
                       
                       ⁢ 
                       
                         
                           1 
                           + 
                           
                             
                               ( 
                               
                                 
                                   ⅆ 
                                   SAG 
                                 
                                 
                                   ⅆ 
                                   H 
                                 
                               
                               ) 
                             
                             2 
                           
                         
                       
                     
                     
                       
                         
                           ⅆ 
                           2 
                         
                         ⁢ 
                         SAG 
                       
                       
                         ⅆ 
                         
                           H 
                           2 
                         
                       
                     
                   
                 
               
             
             
               
                 ( 
                 D 
                 ) 
               
             
           
         
       
     
       
       SAG: a distance from the apex on the aspherical surface to a point on the same aspherical surface having a height H from the optical axis 
       H: a height from an optical axis 
       R is a radius of curvature at the apex on the aspherical surface 
       K: a conical constant 
       D, E, F, G: aspherical coefficients. 
     
  
   It is also preferable that the correcting lens satisfies the following Expression (9), when f is a focal length of the correcting lens and f 34  is a composite focal length of the third and fourth lens groups.
 
0.40&lt;| f 3/ f 34|&lt;0.85  (9)
 
   The expression (9) is a conditional expression to define the focal length of a lens used for correcting camera shake. When the value falls below the lower limit in the expression (9), the correcting lens will have excessive power, deterioration in the aberration performance is increased and assembling tolerance in manufacturing will be strict. When the value exceeds the upper limit, the shifting amount of the lens when correcting camera shake is increased, and the lens diameter also is increased. This is not favorable for downsizing. 
   Preferably, the zoom lens satisfies the following expression (10) when fw is a focal length of the entire system at the wide-angle end, and BF is a distance between the final surface of the lens and the image plane in the air.
 
2.0&lt; BF/fw&lt; 5.0  (10)
 
   The expression (10) is a conditional expression to provide a zoom lens having a long back focus, for example, a zoom lens using three imaging devices. When the value falls below the lower limit, a color separation optical system with sufficient length to conduct a sufficient color separation cannot be inserted. When it exceeds the upper limit, the back focus becomes longer than required, and it will be an obstacle for downsizing. 
   Preferably, the following expressions (11) to (14) are satisfied when fw is a focal length of the entire system at a wide-angle end, fi (i=1-5) is the focal length of the i-th lens group, and f 34  is a composite focal length of the third and fourth focal length.
 
5.0&lt; f 1/ fw&lt; 8.0  (11)
 
0.5&lt;| f 2|/ fw&lt; 1.6  (12)
 
4.0&lt; f 34/ fw&lt; 9.5  (13)
 
2.0&lt; f 5/ fw&lt; 5.0  (14)
 
   The expression (11) indicates a condition relating to the refracting power of the first lens group. Since the first lens group has excessive refracting power when the value falls below the lower limit, correction of spherical aberration at the long focal point side becomes difficult. When it exceeds the upper limit, the lens will be long and thus, a compact zoom lens cannot be obtained. 
   The expression (12) indicates a condition relating to the refracting power of the second lens group. The zoom lens can be made compact when the value falls below the lower limit, however, the Petzval&#39;s sum of the entire system will be increased negatively and distortion of the image plane cannot be corrected. The aberration can be corrected easily when the value exceeds the upper limit, however, the variable power system becomes long and the entire system cannot be downsized. 
   The expression (13) indicates a condition relating to the refracting power of the third lens group. When the value falls below the lower limit, the third lens group will have excessive refracting power, and thus, correction of the spherical aberration will be difficult. When the value exceeds the upper limit, the composite system of the first to third lens group becomes a divergent system. In such a zoom lens, the outer diameter of the lenses of the fourth group positioned behind the first to third groups cannot be decreased, and Petzval&#39;s sum of the entire system cannot be decreased. 
   The expression (14) indicates a condition relating to the refracting power of the fourth lens group. When the value fails below the lower limit, the coverage of an image will be decreased. For obtaining a desired coverage, the lens diameter of the first group should be increased, and thus, this will be an obstacle for downsizing and weight reduction. When the value exceeds the upper limit, the aberration can be corrected easily. However, the shifting amount of the fourth lens group is increased at a close-range shooting, and thus, the entire system cannot be downsized. Moreover, it is difficult to correct unbalanced off-axis aberrations between short-range and long-range shootings. 
   It is also preferable that the following expressions (15) and (16) are satisfied when Y is a shifting amount of a correcting lens at a focal length f of the entire system for correcting camera shake, Yt is a shifting amount of the correcting lens at a telephoto end, and ft is a focal length of the telephoto end.
 
Yt&gt;Y  (15)
 
( Y/Yt )/( f/ft )&lt;1.5  (16)
 
   The expressions (15) and (16) relate to the shifting amount of a correcting lens. For a zoom lens, the shifting amount of the correcting lens is large as the zoom ratio is great, while the same amount is decreased when the zoom ratio is small when the correcting angle is constant within a whole zooming range. When the value exceeds the upper limits of the expressions (15) and (16), overcorrection occurs and the optical performance will deteriorate further. 
   Specific examples for this embodiment are shown in the following Table 43. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 43 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               43.712 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               22.377 
               6.00 
               1.60311 
               60.7 
             
             
                 
               3 
               −147.260 
               0.20 
             
             
                 
               4 
               20.439 
               3.50 
               1.60311 
               60.7 
             
             
                 
               5 
               64.129 
               Variable 
             
             
               2 
               6 
               47.371 
               0.60 
               1.77250 
               49.6 
             
             
                 
               7 
               6.608 
               3.10 
             
             
                 
               8 
               −8.756 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               7.541 
               1.80 
               1.84666 
               23.9 
             
             
                 
               10 
               61.377 
               Variable 
             
             
               3 
               11 
               18.722 
               2.90 
               1.60602 
               57.5 
             
             
                 
               12 
               −14.771 
               0.10 
             
             
                 
               13 
               −61.576 
               0.70 
               1.80518 
               25.4 
             
             
                 
               14 
               82.921 
               2.45 
             
             
               4 
               15 
               −15.486 
               0.70 
               1.51633 
               64.1 
             
             
                 
               16 
               21.635 
               1.65 
               1.80518 
               25.4 
             
             
                 
               17 
               246.689 
               Variable 
             
             
               5 
               18 
               −90.847 
               0.60 
               1.84666 
               23.9 
             
             
                 
               19 
               12.912 
               4.10 
               1.51633 
               64.1 
             
             
                 
               20 
               −18.441 
               0.10 
             
             
                 
               21 
               15.386 
               4.50 
               1.60602 
               57.5 
             
             
                 
               22 
               −15.967 
               Variable 
             
             
               6 
               23 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               24 
               ∞ 
               3.90 
               1.51633 
               64.1 
             
             
                 
               25 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 44 shows aspherical coefficients. 
   
     
       
         
             
             
           
             
                 
               TABLE 44 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               21 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
             
          
             
               K 
                4.65875 × 10 −1   
                1.42780 × 10 −1   
                1.14334 × 10 −1   
               −1.25651 
               −6.94184 × 10 −1   
             
             
               D 
                9.66131 × 10 −5   
               −9.38804 × 10 −5   
                5.30815 × 10 −5   
               −1.94414 × 10 −5   
                2.31291 × 10 −5   
             
             
               E 
               −7.08756 × 10 −6   
                6.02667 × 10 −6   
                5.05125 × 10 −6   
                5.49746 × 10 −7   
                2.50059 × 10 −7   
             
             
               F 
                1.91335 × 10 −7   
               −2.97812 × 10 −7   
               −1.94202 × 10 −7   
               −8.03971 × 10 −9   
               −6.03441 × 10 −9   
             
             
               G 
                0.00000 
                2.28611 × 10 −9   
                0.00000 
                0.00000 
                0.00000 
             
             
                 
             
          
         
       
     
   
   The following Table 45 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position magnification of the second lens group becomes −1 times. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 45 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.166 
               23.073 
               48.386 
             
             
                 
               F/NO 
               1.680 
               1.680 
               1.886 
             
             
                 
               2ω 
               60.226 
               11.023 
               4.354 
             
             
                 
               d5 
               0.700 
               15.560 
               18.886 
             
             
                 
               d10 
               19.216 
               4.356 
               1.030 
             
             
                 
               d14 
               5.331 
               1.967 
               4.258 
             
             
                 
               d19 
               1.099 
               4.463 
               2.172 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 47-49  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. The values of the expressions (6) to (14) are as follows.
 |v31-v32|=32.3 |v41-v42|=38.7   rS 1/ rS 9=0.52 | f 3/ f 34|=0.64   BF/fw= 3.34   f 1/ fw= 7.19 | f 2|/ fw= 1.28   f 34/ fw= 7.61   f 5/ fw= 3.14 
   As clearly shown in the aberrations of  FIGS. 47-49 , this example provides sufficient performance to correct aberration for obtaining high resolution of a zoom lens. 
   Furthermore, this example is useful in preventing deterioration of the optical performance since the expressions (15) and (16) are satisfied. 
   Other specific examples according to this embodiment are shown in the following Table 46. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 46 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               45.790 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               22.855 
               5.80 
               1.60311 
               60.7 
             
             
                 
               3 
               −137.451 
               0.15 
             
             
                 
               4 
               20.654 
               3.15 
               1.60311 
               60.7 
             
             
                 
               5 
               66.413 
               Variable 
             
             
               2 
               6 
               49.547 
               0.60 
               1.51633 
               64.1 
             
             
                 
               7 
               5.943 
               3.65 
             
             
                 
               8 
               −8.260 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               7.608 
               2.01 
               1.84666 
               23.9 
             
             
                 
               10 
               31.856 
               Variable 
             
             
               3 
               11 
               20.308 
               2.80 
               1.51450 
               63.1 
             
             
                 
               12 
               −11.071 
               0.10 
             
             
                 
               13 
               −32.200 
               0.70 
               1.80518 
               25.4 
             
             
                 
               14 
               −179.621 
               2.45 
             
             
               4 
               15 
               −11.566 
               0.70 
               1.51450 
               63.1 
             
             
                 
               16 
               18.674 
               1.50 
               1.80518 
               25.4 
             
             
                 
               17 
               −382.316 
               Variable 
             
             
               5 
               18 
               139.563 
               0.60 
               1.84666 
               23.9 
             
             
                 
               19 
               11.702 
               3.70 
               1.51633 
               64.1 
             
             
                 
               20 
               −27.808 
               0.10 
             
             
                 
               21 
               13.425 
               4.90 
               1.51450 
               63.1 
             
             
                 
               22 
               −12.590 
               Variable 
             
             
               6 
               23 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               24 
               ∞ 
               3.90 
               1.51633 
               64.1 
             
             
                 
               25 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 47 shows aspherical coefficients. 
   
     
       
         
             
             
           
             
                 
               TABLE 47 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               21 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
             
          
             
               K 
                2.65508 × 10 −1   
                3.81101 × 10 −1   
                0.00000 
               −9.36333 × 10 −1   
               −8.93853 × 10 −1   
             
             
               D 
                2.27944 × 10 −4   
               −2.03395 × 10 −4   
               −2.15420 × 10 −5   
               −4.92768 × 10 −5   
                4.67131 × 10 −5   
             
             
               E 
               −4.63825 × 10 −6   
                3.74881 × 10 −6   
                2.89479 × 10 −6   
                7.98657 × 10 −7   
                1.88913 × 10 −7   
             
             
               F 
                1.53384 × 10 −7   
               −2.17585 × 10 −7   
               −1.16142 × 10 −7   
               −1.25522 × 10 −8   
               −9.70141 × 10 −9   
             
             
               G 
                0.00000 
                2.28611 × 10 −9   
                0.00000 
                0.00000 
                0.00000 
             
             
                 
             
          
         
       
     
   
   The following Table 48 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 48 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.196 
               23.529 
               49.156 
             
             
                 
               F/NO 
               1.668 
               1.682 
               1.907 
             
             
                 
               2ω 
               59.743 
               10.822 
               5.414 
             
             
                 
               d5 
               0.700 
               14.055 
               17.374 
             
             
                 
               d10 
               19.204 
               5.842 
               2.530 
             
             
                 
               d14 
               5.831 
               2.402 
               4.737 
             
             
                 
               d19 
               0.995 
               4.425 
               2.090 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 50-52  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. The values of the expressions (6) to (14) are as follows.
 |v31-v32|=37.7 |v41-v42|=37.7   rS 1/ rS 9=0.07 | f 3/ f 34|=0.57   BF/fw= 3.29   f 1/ fw= 7.22 | f 2|/ fw= 1.28   f 34/ fw= 8.40   f 5/ fw= 3.15 
   As clearly shown in the aberrations of  FIGS. 50-52 , this example provides sufficient performance to correct aberration to obtain high resolution of a zoom lens. Furthermore, this example is useful in preventing deterioration of the optical performance since the expressions (15) and (16) are satisfied. 
   Other specific examples according to this embodiment are shown in the following Table 49. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 49 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               −43.258 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               22.067 
               5.80 
               1.60311 
               60.7 
             
             
                 
               3 
               −141.493 
               0.15 
             
             
                 
               4 
               20.338 
               3.15 
               1.60311 
               60.7 
             
             
                 
               5 
               64.306 
               Variable 
             
             
               2 
               6 
               46.991 
               0.60 
               1.77250 
               49.6 
             
             
                 
               7 
               6.645 
               3.10 
             
             
                 
               8 
               −8.848 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               7.368 
               1.60 
               1.84666 
               23.9 
             
             
                 
               10 
               53.923 
               Variable 
             
             
               3 
               11 
               16.972 
               2.61 
               1.60602 
               57.5 
             
             
                 
               12 
               −13.177 
               0.09 
             
             
                 
               13 
               −55.938 
               0.70 
               1.80518 
               25.4 
             
             
                 
               14 
               73.946 
               2.45 
             
             
               4 
               15 
               −17.219 
               0.77 
               1.51633 
               64.1 
             
             
                 
               16 
               22.997 
               1.82 
               1.80518 
               25.4 
             
             
                 
               17 
               288.894 
               Variable 
             
             
               5 
               18 
               −88.752 
               0.60 
               1.84666 
               23.9 
             
             
                 
               19 
               12.766 
               4.50 
               1.51633 
               64.1 
             
             
                 
               20 
               −18.677 
               0.10 
             
             
                 
               21 
               15.561 
               5.00 
               1.60602 
               57.6 
             
             
                 
               22 
               −16.083 
               Variable 
             
             
               6 
               23 
               ∞ 
               13.00 
               1.58913 
               61.2 
             
             
                 
               24 
               ∞ 
               3.00 
               1.51633 
               64.1 
             
             
                 
               25 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 50 shows aspherical coefficients. 
   
     
       
         
             
             
           
             
                 
               TABLE 50 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               21 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
             
          
             
               K 
                4.747248 × 10 −1   
                2.101119 × 10 −1   
                1.007413 × 10 −1   
               −1.279930 
               −6.730536 × 10 −1   
             
             
               D 
                4.453156 × 10 −5   
               −9.582481 × 10 −5   
                9.286602 × 10 −5   
                9.244688 × 10 −6   
                3.352961 × 10 −5   
             
             
               E 
               −7.953517 × 10 −7   
                1.260729 × 10 −6   
                1.333902 × 10 −7   
               −1.306964 × 10 −7   
               −3.521187 × 10 −7   
             
             
               F 
               −5.757966 × 10 −8   
               −2.487044 × 10 −7   
               −5.579667 × 10 −8   
                9.358746 × 10 −10   
                1.832323 × 10 −9   
             
             
               G 
                0.000000 
                5.900849 × 10 −9   
                0.000000 
                0.000000 
                0.000000 
             
             
                 
             
          
         
       
     
   
   The following Table 51 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 51 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.256 
               22.469 
               49.343 
             
             
                 
               F/NO 
               1.697 
               1.695 
               1.902 
             
             
                 
               2ω 
               59.068 
               11.284 
               5.401 
             
             
                 
               d5 
               0.700 
               14.053 
               17.391 
             
             
                 
               d10 
               19.212 
               5.867 
               2.530 
             
             
                 
               d14 
               5.831 
               2.537 
               4.742 
             
             
                 
               d19 
               0.855 
               4.149 
               1.944 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 53-55  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. The values of the expressions (6) to (14) are as follows.
 |v31-v32|=32.3 |v41-v42|=38.6   rS 1/ rS 9=0.58 | f 3/ f 34|=0.72   BF/fw= 2.93   f 1/ fw= 6.97 | f 2|/ fw= 1.26   f 34/ fw= 5.89   f 5/ fw= 3.11 
   As clearly shown in the aberrations of  FIGS. 53-55 , this example provides sufficient performance to correct aberration to obtain high resolution of a zoom lens. Furthermore, this example is useful in preventing deterioration of the optical performance since the expressions (15) and (16) are satisfied. 
   Twelfth Embodiment 
     FIG. 56  is a view showing the arrangement of a zoom lens in a twelfth embodiment according to the present invention. As shown in  FIG. 56 , a zoom lens has a structure in which a first lens group  1   a , a second lens group  2   a , a third lens group  3   a , a fourth lens group  4   a  and a fifth lens group  5   a  are disposed from an object side in this order. The first lens group  1   a  has a positive refracting power and is fixed with respect to the image plane. The second lens group  2   a  has a negative refracting power and varies power by moving along an optical axis. The third lens group  3   a  is fixed with respect to the image plane and has a negative refracting power. The fourth lens group  4   a  is fixed with respect to the image plane and has a positive refracting power. The fifth lens group  5   a  has a positive refracting power and moves along an optical axis to keep the image plane varied by the shift of the second lens group and the object at a predetermined position from a reference surface. Camera shake is corrected by shifting the fourth lens group having a positive refracting power in a direction vertical to the optical axis. 
     FIG. 57  shows a zoom lens of the basic structure shown in  FIG. 56 . The zoom lens has a structure in which a first lens group  121 , a second lens group  122 , a third lens group  123 , and a fourth lens group  124  are disposed from the object side to the image plane side in this order. The first lens group  121  has a positive refracting power, and is fixed with respect to the image plane in varying power and focusing. The second lens group  122  has a negative refracting power and varies power by moving along an optical axis. 
   The third lens group  123  is composed of a negative lens and a positive lens, and has a negative refracting power as a whole. The fourth lens group  124  is composed of a positive lens and a negative lens, and has a positive refracting power as a whole. The group is fixed with respect to the image plane in varying power and focusing. A fifth lens group  125  has a positive refracting power, and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the fourth lens group  124  vertically with respect to the optical axis. 
   As described above, light beams entering the fifth lens group  125  can be lowered by combining the third lens group  123  having a negative refracting power and a fourth lens group  124  having a positive refracting power. Namely, the lens diameter of the fourth group can be decreased and a load on an actuator will be decreased in focusing. 
   The performance when shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the fourth group. Similar to the eleventh embodiment, it is preferable that the expressions (6)-(16) are satisfied. 
   Specific examples for this embodiment are shown in the following Table 52. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 52 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               43.700 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               22.310 
               6.00 
               1.60311 
               60.7 
             
             
                 
               3 
               −147.017 
               0.20 
             
             
                 
               4 
               20.415 
               3.50 
               1.60311 
               60.7 
             
             
                 
               5 
               64.027 
               Variable 
             
             
               2 
               6 
               64.027 
               0.60 
               1.77250 
               49.6 
             
             
                 
               7 
               6.600 
               3.10 
             
             
                 
               8 
               −8.963 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               6.685 
               1.80 
               1.80518 
               25.4 
             
             
                 
               10 
               65.269 
               Variable 
             
             
               3 
               11 
               −19.604 
               0.70 
               1.51633 
               64.1 
             
             
                 
               12 
               24.259 
               1.65 
               1.84666 
               23.9 
             
             
                 
               13 
               100.263 
               1.00 
             
             
               4 
               14 
               12.130 
               3.51 
               1.60602 
               57.6 
             
             
                 
               15 
               −14.418 
               0.10 
             
             
                 
               16 
               −42.218 
               0.60 
               1.80518 
               25.4 
             
             
                 
               17 
               56.648 
               Variable 
             
             
               5 
               18 
               −106.725 
               0.70 
               1.80518 
               25.4 
             
             
                 
               19 
               16.919 
               3.60 
               1.51633 
               64.1 
             
             
                 
               20 
               −23.864 
               0.10 
             
             
                 
               21 
               18.527 
               3.60 
               1.60602 
               57.6 
             
             
                 
               22 
               −22.813 
               Variable 
             
             
               6 
               23 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               24 
               ∞ 
               3.90 
               1.51633 
               64.1 
             
             
                 
               25 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 53 shows aspherical coefficients. 
   
     
       
         
             
             
           
             
                 
               TABLE 53 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               21 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
             
          
             
               K 
                5.37219 × 10 −1   
                2.97152 × 10 −1   
               −2.48406 
               −5.61162 
               −5.96501 
             
             
               D 
                8.69130 × 10 −5   
               −1.56550 × 10 −4   
                2.68507 × 10 −5   
                5.63851 × 10 −5   
               −4.80942 × 10 −5   
             
             
               E 
               −5.67323 × 10 −6   
                6.96463 × 10 −8   
                3.64998 × 10 −7   
               −2.49399 × 10 −7   
                3.72704 × 10 −7   
             
             
                 
             
          
         
       
     
   
   The following Table 54 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 54 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.029 
               23.328 
               50.226 
             
             
                 
               F/NO 
               1.650 
               1.776 
               1.966 
             
             
                 
               2ω 
               62.566 
               10.893 
               5.239 
             
             
                 
               d5 
               0.700 
               14.408 
               17.686 
             
             
                 
               d10 
               20.216 
               6.509 
               3.230 
             
             
                 
               d14 
               5.331 
               1.876 
               4.155 
             
             
                 
               d19 
               1.200 
               4.636 
               2.184 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 58-60  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. The values of the expressions (6) to (14) are as follows.
 |v31-v32|=40.2 |v41-v42|=32.3   rS 1/ rS 9=0.74 | f 3/ f 34|=0.69   BF/fw= 3.45   f 1/ fw= 7.43 | f 2|/ fw= 1.29   f 34/ fw= 6.20   f 5/ fw= 4.19 
   As clearly shown in the aberrations of  FIGS. 58-60 , this example provides sufficient performance to correct aberration to obtain high resolution of a zoom lens. Furthermore, this example is useful in preventing deterioration of the optical system since the expressions (15) and (16) are satisfied. 
   Thirteenth Embodiment 
     FIG. 61  is a view showing the arrangement of a zoom lens in a thirteenth embodiment according to the present invention. As shown in  FIG. 61 , a zoom lens has a structure in which a first lens group  161 , a second lens group  162 , a third lens group  163 , and a fourth lens group  164  are disposed from an object side to an image plane side in this order. The first lens group  161  has a positive refracting power, and is fixed with respect to the image plane in varying power and focusing. The second lens group  162  has a negative refracting power and varies power by moving along an optical axis. 
   The third lens group  163  is a cemented lens composed of two lenses and it has a positive refracting power. The fourth lens group  164  has a negative refracting power and is fixed with respect to the image plane in varying power and focusing. A fifth lens group  165  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  163  vertically with respect to the optical axis. The tolerance can be eased by making the shift lens group  163  a cemented lens. 
   Performance when shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the third group. Similar to the eleventh embodiment, it is preferable that the expressions (6)-(16) are satisfied. 
   Specific examples for this embodiment are shown in the following Table 55. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 55 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               43.712 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               22.377 
               6.00 
               1.60311 
               60.7 
             
             
                 
               3 
               −147.260 
               0.20 
             
             
                 
               4 
               20.439 
               3.50 
               1.60311 
               60.7 
             
             
                 
               5 
               64.129 
               Variable 
             
             
               2 
               6 
               47.371 
               0.60 
               1.77250 
               49.6 
             
             
                 
               7 
               6.608 
               3.10 
             
             
                 
               8 
               −8.756 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               7.541 
               1.80 
               1.84666 
               23.9 
             
             
                 
               10 
               61.377 
               Variable 
             
             
               3 
               11 
               11.304 
               2.00 
               1.60602 
               57.5 
             
             
                 
               12 
               29.656 
               1.00 
               1.80518 
               25.4 
             
             
                 
               13 
               71.482 
               2.45 
             
             
               4 
               14 
               −45.255 
               0.70 
               1.51633 
               64.1 
             
             
                 
               15 
               13.342 
               1.65 
               1.80518 
               25.4 
             
             
                 
               16 
               23.203 
               Variable 
             
             
               5 
               17 
               −88.752 
               0.60 
               1.84666 
               23.9 
             
             
                 
               18 
               12.766 
               4.10 
               1.51633 
               64.1 
             
             
                 
               19 
               −18.677 
               0.10 
             
             
                 
               20 
               15.561 
               4.50 
               1.60602 
               57.6 
             
             
                 
               21 
               −16.083 
               Variable 
             
             
               6 
               22 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               23 
               ∞ 
               3.90 
               1.51633 
               64.1 
             
             
                 
               24 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 56 shows aspherical coefficients. 
   
     
       
         
             
             
           
             
                 
               TABLE 56 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               21 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
             
          
             
               K 
                4.65875 × 10 −1   
                1.42789 × 10 −1   
                1.14334 × 10 −1   
               −1.256510 
               −6.94184 × 10 −1   
             
             
               D 
                9.66131 × 10 −5   
                2.50260 × 10 −4   
                3.81894 × 10 −4   
               −2.86326 × 10 −5   
               −1.87081 × 10 −5   
             
             
               E 
               −7.08756 × 10 −7   
                9.98537 × 10 −6   
                1.14292 × 10 −5   
                4.11743 × 10 −7   
                1.01992 × 10 −7   
             
             
               F 
                1.91335 × 10 −7   
               −2.16512 × 10 −7   
               −1.11482 × 10 −7   
               −9.63753 × 10 −9   
               −5.68100 × 10 −9   
             
             
               G 
                0.00000 
                2.28611 × 10 −9   
                0.00000 
                0.00000 
                0.00000 
             
             
                 
             
          
         
       
     
   
   The following Table 57 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 57 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               4.153 
               23.052 
               48.765 
             
             
                 
               F/NO 
               1.853 
               1.952 
               1.877 
             
             
                 
               2ω 
               60.636 
               11.025 
               5.426 
             
             
                 
               d5 
               0.700 
               14.060 
               17.386 
             
             
                 
               d10 
               19.216 
               5.856 
               2.530 
             
             
                 
               d14 
               5.331 
               1.967 
               4.261 
             
             
                 
               d19 
               1.200 
               4.846 
               2.532 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 62-64  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. The values of the expressions (6) to (14) are as follows.
 |v31-v32|=32.3 |v41-v42|=38.6   rS 1/ rS 9=1.49 | f 3/ f 34|=0.66   BF/fw= 3.36   f 1/ fw= 7.21 | f 2|/ fw= 1.29   f 34/ fw= 7.35   f 5/ fw= 2.96 
   As clearly shown in the aberrations of  FIGS. 62-64 , this example provides sufficient performance to correct aberration to obtain high resolution of a zoom lens. Furthermore, this example is useful in preventing deterioration of the optical performance since the expressions (15) and (16) are satisfied. 
   Fourteenth Embodiment 
   This embodiment relates to a video camera using three imaging devices where the video camera has a function to correct camera shake by using a zoom lens in any of the eleventh to thirteenth embodiments, and the structure is shown in  FIG. 65 . 
   A video camera according to this embodiment comprises a zoom lens  201  of the eleventh embodiment, a low-pass filter  202 , prisms  203   a - 203   c  for color separation, imagers  204   a - 204   c , a signal processing circuit  205 , a view finder  206 , a sensor  207  for detecting camera shake, and an actuator  208  for driving the lens. 
   The zoom lens is not limited to what is shown in the eleventh embodiment, but zoom lenses described in the twelfth and thirteenth embodiments also can be used, though they are not shown specifically in any figures. 
   Although the shift lens group is composed of two single lenses in the eleventh to thirteenth embodiments, the lenses can be a cemented lens to ease the tolerance. 
   Although camera shake is corrected by shifting a lens group having a positive refracting power in the eleventh to thirteenth embodiments, similar effects can be obtained by shifting a lens group having a negative refracting power. 
   Fifteenth Embodiment 
     FIG. 66  is a view showing the arrangement of a zoom lens in a fifteenth embodiment according to the present invention. As shown in  FIG. 66 , a zoom lens has a structure in which a first lens group  21 , a second lens group  22 , a third lens group  23 , a fourth lens group  24 , and a fifth lens group  25  are disposed from an object side deft side in  FIG. 66 ) to an image plane side (right side in  FIG. 66 ) in this order. 
   The first lens group  21  has a positive refracting power and is fixed with respect to the image plane in varying power and focusing. The second lens group  22  has a negative refracting power and varies power by moving along an optical axis. The third lens group  23  is composed of three lenses: a negative lens, a positive lens and a positive lens disposed from the object side in this order. This group includes at least one aspherical surface and has a positive refracting power as a whole. 
   The fourth lens group  24  is composed of two lenses as a cemented lens of a negative lens and a positive lens disposed from the object side in this order and it has a negative refracting power as a whole, and is fixed with respect to the image plane in varying power and focusing. The fifth lens group  25  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with the variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  23  vertically with respect to the optical axis. 
   The performance when shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the third group  23 . 
   It is preferable that the above-described expression (8) about aspherical surface amount is satisfied for the third lens group  23  when rS 1  represents a local radius of curvature for a diameter occupying 10% of the lens effective diameter, and rS 9  is a local radius of curvature for a diameter occupying 90% of lens effective diameter. 
   Here, the local radius of curvature C is obtainable through an algebraic calculation based on aspherical coefficients figured out from the sag amount of the plane shape. It is obtainable by the following equations (E) and (F). 
   
     
       
         
           
             
               
                 SAG 
                 = 
                 
                   
                     
                       
                         H 
                         2 
                       
                       / 
                       R 
                     
                     
                       1 
                       + 
                       
                         
                           1 
                           - 
                           
                             
                               ( 
                               
                                 1 
                                 + 
                                 K 
                               
                               ) 
                             
                             ⁢ 
                             
                               
                                 ( 
                                 
                                   H 
                                   / 
                                   R 
                                 
                                 ) 
                               
                               2 
                             
                           
                         
                       
                     
                   
                   + 
                   
                     D 
                     · 
                     
                       H 
                       4 
                     
                   
                   + 
                   
                     E 
                     · 
                     
                       H 
                       6 
                     
                   
                 
               
             
             
               
                 ( 
                 E 
                 ) 
               
             
           
           
             
               
                 C 
                 = 
                 
                   
                     
                       ( 
                       
                         1 
                         + 
                         
                           
                             ( 
                             
                               
                                 ⅆ 
                                 SAG 
                               
                               
                                 ⅆ 
                                 H 
                               
                             
                             ) 
                           
                           2 
                         
                       
                       ) 
                     
                     ⁢ 
                     
                       
                         1 
                         + 
                         
                           
                             ( 
                             
                               
                                 ⅆ 
                                 SAG 
                               
                               
                                 ⅆ 
                                 H 
                               
                             
                             ) 
                           
                           2 
                         
                       
                     
                   
                   
                     
                       
                         ⅆ 
                         2 
                       
                       ⁢ 
                       SAG 
                     
                     
                       ⅆ 
                       
                         H 
                         2 
                       
                     
                   
                 
               
             
             
               
                 ( 
                 F 
                 ) 
               
             
           
         
       
     
       
       SAG: a distance from the apex on the aspherical surface to a point on the same aspherical surface having a height H from the optical axis 
       H: a height from an optical axis 
       R is a radius of curvature at the apex on the aspherical surface 
       K: a conical constant 
       D, E: aspherical coefficients 
       C: local radius of curvature 
     
  
   It is also preferable that the correcting lens satisfies the expression (9), when f 3  is the focal length of the third lens group  23  (a correcting lens group) and f 34  is a composite focal length of the third and fourth lens groups. 
   Preferably, the expression (10) is satisfied when fv is a focal length of the entire system at the wide-angle end, and BF is a distance between the final surface of the lens and the image plane in the air. 
   Preferably, the expressions (11) to (14) are satisfied when fw is a focal length of the entire system at a wide-angle end, fi (i=1−5) is the focal length of the i-th lens group, and f 34  is a composite focal length of the third and fourth lens group  23 ,  24 . 
   It is also preferable that the expressions (15) and (16) are satisfied when Y is a shifting amount of the third lens group  23  at a focal length f of the entire system when correcting camera shake, Yt is a shifting amount of the third lens group  23  at the telephoto end, and ft is a focal length of the telephoto end. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 58. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 58 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               35.243 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               18.353 
               5.25 
               1.60311 
               60.7 
             
             
                 
               3 
               −154.339 
               0.15 
             
             
                 
               4 
               17.449 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               53.989 
               Variable 
             
             
               2 
               6 
               53.989 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               5.142 
               2.97 
             
             
                 
               8 
               −7.948 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               5.519 
               2.70 
               1.80518 
               25.4 
             
             
                 
               10 
               1291.253 
               Variable 
             
             
               3 
               11 
               136.351 
               1.00 
               1.84666 
               23.9 
             
             
                 
               12 
               24.057 
               0.50 
             
             
                 
               13 
               16.099 
               1.70 
               1.51450 
               63.1 
             
             
                 
               14 
               −199.059 
               0.50 
             
             
                 
               15 
               48.853 
               1.90 
               1.58913 
               61.2 
             
             
                 
               16 
               −18.181 
               2.70 
             
             
               4 
               17 
               −22.167 
               0.80 
               1.58913 
               61.2 
             
             
                 
               18 
               12.517 
               1.60 
               1.80518 
               25.4 
             
             
                 
               19 
               52.330 
               Variable 
             
             
               5 
               20 
               −42.760 
               0.60 
               1.84666 
               23.9 
             
             
                 
               21 
               15.607 
               2.80 
               1.51633 
               64.1 
             
             
                 
               22 
               −14.704 
               0.10 
             
             
                 
               23 
               12.767 
               3.00 
               1.51450 
               63.1 
             
             
                 
               24 
               −16.499 
               Variable 
             
             
               6 
               25 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               26 
               ∞ 
               2.80 
               1.51633 
               64.1 
             
             
                 
               27 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 59 shows aspherical coefficients of the zoom lens in the present example. 
   
     
       
         
             
             
             
           
             
                 
               TABLE 59 
             
           
          
             
                 
                 
             
             
                 
               Surface 
                 
             
          
         
         
             
             
             
             
          
             
                 
               8 
               13 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
          
             
               K 
               −4.89985 
               −8.46317 
               −1.14637 
             
             
               D 
               −1.08175 × 10 −3   
                1.00945 × 10 −4   
               −6.03706 × 10 −5   
             
             
               E 
               −1.06040 × 10 −5   
               −1.63114 × 10 −6   
               −8.33884 × 10 −6   
             
             
                 
             
          
         
       
     
   
   The following Table 60 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position, magnification of the second lens group  22  becomes −1 times in Table 60. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 60 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.680 
               17.737 
               42.686 
             
             
                 
               F/NO 
               1.658 
               1.914 
               2.072 
             
             
                 
               2ω 
               58.508 
               12.362 
               5.106 
             
             
                 
               d5 
               0.600 
               11.675 
               14.927 
             
             
                 
               d10 
               17.903 
               6.827 
               3.575 
             
             
                 
               d14 
               5.200 
               2.519 
               5.200 
             
             
                 
               d19 
               1.000 
               3.682 
               1.000 
             
             
                 
                 
             
          
         
       
     
   
   The values of the expressions (8) to (14) are as follows.
 
 rS 1/ rS 9=0.64
 
| f 3/ f 34|=0.59
 
 BF/fw= 4.09
 
 f 1/ fw= 7.00
 
| f 2|/ fw= 1.25
 
 f 34/ fw= 9.14
 
 f 5/ fw= 3.79
 
   In this example, the above-described expression (8) is satisfied, and a sufficient aberration performance is provided to realize high resolution. Since the expression (9) is satisfied, deterioration in the aberration performance can be decreased and assembly tolerance in manufacturing can be eased. Moreover, since the shifting amount of the lenses is decreased when correcting camera shake, the lens diameter can be reduced for downsizing. Furthermore, since the expression (10) is satisfied, a color separation optical system having a length for a sufficient color separation can be inserted. 
   Furthermore, the back focus does not need to have extra length, and a small zoom lens can be provided. Since the expressions (11) to (14) are satisfied, the aberration can be corrected easily and the zoom lens can be downsized. 
     FIGS. 67-69  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. As clearly shown in the aberrations of  FIGS. 67-69 , this example provides sufficient performance to correct aberration to obtain high resolution of a zoom lens. 
   Sixteenth Embodiment 
     FIG. 70  is a view showing the arrangement of a zoom lens in a sixteenth embodiment according to the present invention. As shown in  FIG. 70 , a zoom lens has a structure in which a first lens group  701 , a second lens group  702 , a third lens group  703 , a fourth lens group  704 , and a fifth lens group  705  are disposed from an object side deft side in  FIG. 70 ) to an image plane side (right side in  FIG. 70 ) in this order. 
   The first lens group  701  has a positive refracting power and is fixed with respect to the image plane in varying power and focusing. The second lens group  702  has a negative refracting power and varies power by moving along an optical axis. 
   The third lens group  703  is composed of three lenses: a negative lens, a positive lens and a positive lens disposed from the object side in this order. This group includes at least one aspherical surface and has a positive refracting power as a whole. 
   The fourth lens group  704  is composed of two lenses as a cemented lens of a negative lens and a positive lens disposed from the object side in this order and this group has a negative refracting power as a whole, and is fixed with respect to the image plane in varying power and focusing. The fifth lens group  705  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  703  vertically with respect to the optical axis. 
   The performance at shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the third group  703 . 
   Similar to the fifteenth embodiment, it is preferable for the zoom lens of his embodiment that the conditional expressions (8)-(16) are satisfied. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 61. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 61 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               35.243 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               18.353 
               5.25 
               1.60311 
               60.7 
             
             
                 
               3 
               −154.339 
               0.15 
             
             
                 
               4 
               17.449 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               53.989 
               Variable 
             
             
               2 
               6 
               53.989 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               5.142 
               2.97 
             
             
                 
               8 
               −7.948 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               5.519 
               2.70 
               1.80518 
               25.4 
             
             
                 
               10 
               1291.253 
               Variable 
             
             
               3 
               11 
               58.041 
               1.00 
               1.51450 
               63.1 
             
             
                 
               12 
               −19.193 
               0.50 
             
             
                 
               13 
               −18.810 
               1.70 
               1.84666 
               23.9 
             
             
                 
               14 
               −59.301 
               0.50 
             
             
                 
               15 
               43.566 
               1.90 
               1.58913 
               61.2 
             
             
                 
               16 
               −17.985 
               2.70 
             
             
               4 
               17 
               −20.041 
               0.80 
               1.58913 
               61.2 
             
             
                 
               18 
               12.918 
               1.60 
               1.80518 
               25.4 
             
             
                 
               19 
               63.402 
               Variable 
             
             
               5 
               20 
               −51.268 
               0.60 
               1.84666 
               23.9 
             
             
                 
               21 
               15.447 
               2.80 
               1.51633 
               64.1 
             
             
                 
               22 
               −14.704 
               0.10 
             
             
                 
               23 
               12.767 
               3.00 
               1.51450 
               63.1 
             
             
                 
               24 
               −16.499 
               Variable 
             
             
               6 
               25 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               26 
               ∞ 
               2.80 
               1.51633 
               64.1 
             
             
                 
               27 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 62 shows aspherical coefficients of the zoom lens in the present example. 
   
     
       
         
             
             
             
           
             
                 
               TABLE 62 
             
           
          
             
                 
                 
             
             
                 
               Surface 
                 
             
          
         
         
             
             
             
             
          
             
                 
               8 
               13 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
          
             
               K 
               −4.89985 
               −8.44752 
               −9.50310 × 10 −1   
             
             
               D 
               −1.08175 × 10 −3   
               −4.24504 × 10 −5   
               −4.89670 × 10 −5   
             
             
               E 
               −1.06040 × 10 −5   
                7.84853 × 10 −7   
               −6.72180 × 10 −8   
             
             
                 
             
          
         
       
     
   
   The following Table 63 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position, magnification of the second lens group  702  becomes −1 times in Table 63. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 63 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.691 
               17.802 
               42.813 
             
             
                 
               F/NO 
               1.657 
               1.925 
               2.078 
             
             
                 
               2ω 
               58.349 
               12.321 
               42.813 
             
             
                 
               d5 
               0.600 
               11.675 
               14.927 
             
             
                 
               d10 
               17.903 
               6.827 
               13.575 
             
             
                 
               d14 
               5.200 
               2.485 
               5.200 
             
             
                 
               d19 
               1.000 
               3.715 
               1.000 
             
             
                 
                 
             
          
         
       
     
   
   The values of the expressions (8) to (14) are as follows.
 
 rS 1/ rS 9=0.63
 
| f 3/ f 34|=0.59
 
 BF/fw= 4.01
 
 f 1/ fw= 6.98
 
| f 2|/ fw= 1.25
 
 f 34/ fw= 9.17
 
 f 5/ fw= 3.70
 
     FIGS. 71-73  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. As clearly shown in the aberrations of  FIGS. 71-73 , a zoom lens according to this embodiment has sufficient performance to correct aberration to realize high resolution. 
   Seventeenth Embodiment 
     FIG. 74  is a view showing the arrangement of a zoom lens in a seventeenth embodiment according to the present invention. As shown in  FIG. 74 , a zoom lens has a structure in which a first lens group  101 , a second lens group  102 , a third lens group  103 , a fourth lens group  104 , and a fifth lens group  105  are disposed from an object side (left side in  FIG. 74 ) to an image plane side (right side in  FIG. 74 ) in this order. 
   The first lens group  101  has a positive refracting power and is fixed with respect to the image plane in varying power and focusing. The second lens group  102  has a negative refracting power and varies power by moving along an optical axis. The third lens group  103  is composed of three lenses: a positive lens, a positive lens and a negative lens disposed from the object side in this order. The third lens group includes at least one aspherical surface and has a positive refracting power as a whole. The fourth lens group  104  is composed of two lenses as a cemented lens of a negative lens and a positive lens disposed from the object side in this order, and this group has a negative refracting power as a whole, and is fixed with respect to the image plane in varying power and focusing. The fifth lens group  105  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  103  vertically with respect to the optical axis. 
   As mentioned above, the performance when shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the third lens group  103 . 
   Similar to the first embodiment, it is preferable for the zoom lens of this embodiment that the conditional expressions (8)-(16) are satisfied. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 64. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 64 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               35.243 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               18.353 
               5.25 
               1.60311 
               60.7 
             
             
                 
               3 
               −154.339 
               0.15 
             
             
                 
               4 
               17.449 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               53.989 
               Variable 
             
             
               2 
               6 
               53.989 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               5.142 
               2.97 
             
             
                 
               8 
               −7.948 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               5.519 
               2.70 
               1.80518 
               25.4 
             
             
                 
               10 
               1291.253 
               Variable 
             
             
               3 
               11 
               1044.254 
               1.70 
               1.51450 
               63.1 
             
             
                 
               12 
               −16.361 
               0.10 
             
             
                 
               13 
               15.774 
               1.90 
               1.58913 
               61.2 
             
             
                 
               14 
               −45.969 
               0.50 
             
             
                 
               15 
               −46.430 
               1.90 
               1.80518 
               25.4 
             
             
                 
               16 
               42.087 
               2.70 
             
             
               4 
               17 
               −20.461 
               0.80 
               1.58913 
               61.2 
             
             
                 
               18 
               16.458 
               1.60 
               1.80518 
               25.4 
             
             
                 
               19 
               63.911 
               Variable 
             
             
               5 
               20 
               −54.786 
               0.60 
               1.84666 
               23.9 
             
             
                 
               21 
               18.645 
               2.80 
               1.51633 
               64.1 
             
             
                 
               22 
               −12.273 
               0.10 
             
             
                 
               23 
               11.361 
               3.00 
               1.51450 
               63.1 
             
             
                 
               24 
               −19.962 
               Variable 
             
             
               6 
               25 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               26 
               ∞ 
               2.80 
               1.51633 
               64.1 
             
             
                 
               27 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 65 shows aspherical coefficients of the zoom lens in the present example. 
   
     
       
         
             
             
             
           
             
                 
               TABLE 65 
             
           
          
             
                 
                 
             
             
                 
               Surface 
                 
             
          
         
         
             
             
             
             
          
             
                 
               8 
               13 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
          
             
               K 
               −4.89985 
               −4.53315 
               −8.12542 × 10 −1   
             
             
               D 
               −1.08175 × 10 −3   
               −6.30517 × 10 −5   
               −5.78738 × 10 −5   
             
             
               E 
               −1.06040 × 10 −5   
                2.50225 × 10 −7   
               −1.83558 × 10 −7   
             
             
                 
             
          
         
       
     
   
   The following Table 66 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position magnification of the second lens group  102  becomes −1 times in Table 66. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 66 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.685 
               18.123 
               42.738 
             
             
                 
               F/NO 
               1.657 
               1.879 
               2.074 
             
             
                 
               2ω 
               58.363 
               12.121 
               5.093 
             
             
                 
               d5 
               0.600 
               11.675 
               14.927 
             
             
                 
               d10 
               17.902 
               6.827 
               3.575 
             
             
                 
               d14 
               5.200 
               2.329 
               5.200 
             
             
                 
               d19 
               1.000 
               3.871 
               1.000 
             
             
                 
                 
             
          
         
       
     
   
     FIGS. 75-77  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. As clearly shown in the aberrations of  FIGS. 75-77 , a zoom lens according to this embodiment has sufficient performance to correct aberration to realize high resolution. 
   Eighteenth Embodiment 
     FIG. 78  is a view showing the arrangement of a zoom lens in an eighteenth embodiment according to the present invention. As shown in  FIG. 78 , a zoom lens has a structure in which a first lens group  141 , a second lens group  142 , a third lens group  143 , a fourth lens group  144 , and a fifth lens group  145  are disposed from an object side (left side in  FIG. 78 ) to an image plane side (right side in  FIG. 78 ) in this order. 
   The first lens group  141  has a positive refracting power and is fixed with respect to the image plane in varying power and focusing. The second lens group  142  has a negative refracting power and varies power by moving along an optical axis. The third lens group  143  is composed of two lenses: a positive lens and a negative lens disposed from the object side in this order. The lenses of the third group have surfaces equal to each other in the sag amount, and this group has a positive refracting power as a whole. 
   The fourth lens group  144  is composed of two lenses as a cemented lens of a negative lens and a positive lens disposed from the object side in this order, and this group has a negative refracting power as a whole, and is fixed with respect to the image plane in varying power and focusing. The fifth lens group  145  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  143  vertically with respect to the optical axis. 
   As described above, light beams entering the fifth lens group  145  can be lowered by combining the third lens group  143  having a positive refracting power as a whole and the fourth lens group  144  having a negative refracting power as a whole. Namely, since the lens diameter of the fourth group  144  can be decreased, a load on an actuator will be lighter in focusing. 
   The performance at shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the third group  143 . 
   Similar to the fourteenth embodiment, it is preferable for the zoom lens of this embodiment that the conditional expressions (8)-(16) are satisfied. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 67. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 67 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               35.171 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               18.474 
               5.25 
               1.60311 
               60.7 
             
             
                 
               3 
               −153.872 
               0.15 
             
             
                 
               4 
               17.397 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               52.501 
               Variable 
             
             
               2 
               6 
               52.501 
               0.60 
               1.78500 
               43.7 
             
             
                 
               7 
               5.178 
               2.97 
             
             
                 
               8 
               −7.914 
               1.00 
               1.66547 
               55.2 
             
             
                 
               9 
               5.841 
               2.70 
               1.80518 
               25.4 
             
             
                 
               10 
               ∞ 
               Variable 
             
             
               3 
               11 
               13.430 
               3.00 
               1.51450 
               63.1 
             
             
                 
               12 
               −13.430 
               0.60 
             
             
                 
               13 
               −45.224 
               1.20 
               1.80518 
               25.4 
             
             
                 
               14 
               84.188 
               2.60 
             
             
               4 
               15 
               −23.195 
               0.60 
               1.58913 
               61.2 
             
             
                 
               16 
               23.195 
               1.50 
               1.80518 
               25.4 
             
             
                 
               17 
               70.085 
               Variable 
             
             
               5 
               18 
               −56.351 
               0.60 
               1.84666 
               23.9 
             
             
                 
               19 
               18.833 
               2.80 
               1.51633 
               64.1 
             
             
                 
               20 
               −13.089 
               0.10 
             
             
                 
               21 
               11.081 
               2.85 
               1.51450 
               63.1 
             
             
                 
               22 
               −19.280 
               Variable 
             
             
               6 
               23 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               24 
               ∞ 
               2.80 
               1.51633 
               64.1 
             
             
                 
               25 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 68 shows aspherical coefficients of the zoom lens in the present example. 
   
     
       
         
             
             
           
             
                 
               TABLE 68 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               20 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −8.93826 × 10 −1   
               −1.54989 
               −1.54989 
               −5.29341 × 10 −1   
             
             
               D 
               −1.30720 × 10 −4   
               −3.86132 × 10 −5   
                3.86132 × 10 −5   
               −8.85522 × 10 −5   
             
             
               E 
               −2.38410 × 10 −5   
                2.40598 × 10 −7   
               −2.40598 × 10 −7   
               −2.60439 × 10 −7   
             
             
                 
             
          
         
       
     
   
   The following Table 69 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position, magnification of the second lens group  142  becomes −1 times in Table 69. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 69 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.681 
               18.240 
               42.656 
             
             
                 
               F/NO 
               1.655 
               1.874 
               2.067 
             
             
                 
               2ω 
               58.529 
               12.076 
               5.120 
             
             
                 
               d5 
               0.600 
               11.710 
               14.974 
             
             
                 
               d10 
               17.503 
               6.393 
               3.129 
             
             
                 
               d14 
               5.200 
               2.321 
               5.200 
             
             
                 
               d19 
               1.000 
               3.879 
               1.000 
             
             
                 
                 
             
          
         
       
     
   
   The values of the expressions (8) to (14) are as follows.
 
 rS 1/ rS 9=0.79
 
| f 3/ f 34|=0.62
 
 BF/fw= 3.58
 
 f 1/ fw= 7.00
 
|f2|/ fw= 1.26
 
 f 34/ fw= 8.83
 
 f 5/ fw= 3.23
 
     FIGS. 79-81  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. As clearly shown in the aberrations of  FIGS. 79-81 , a zoom lens according to this embodiment has sufficient performance to correct aberration to realize high resolution. 
   Nineteenth Embodiment 
     FIG. 82  is a view showing the arrangement of a zoom lens in a nineteenth embodiment according to the present invention. As shown in  FIG. 82 , a zoom lens has a structure in which a first lens group  181 , a second lens group  182 , a third lens group  183 , a fourth lens group  184 , and a fifth lens group  185  are disposed from an object side (left side in  FIG. 82 ) to an image plane side (right side in  FIG. 82 ) in this order. 
   The first lens group  181  has a positive refracting power and is fixed with respect to the image plane in varying power and focusing. The second lens group  182  has a negative refracting power and varies power by moving along an optical axis. The third lens group  183  is composed of one lens having a positive refracting power. 
   The fourth lens group  184  is composed of two lenses as a cemented lens of a negative lens and a positive lens disposed from the object side in this order and this group has a negative refracting power as a whole, and is fixed with respect to the image plane varying power and focusing. The fifth lens group  185  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  183  vertically with respect to the optical axis. 
   As a result, the tolerance can be eased by forming a shift lens group (the third lens group  183 ) with one lens. 
   The performance when shifting the lens can be improved by applying at least one aspherical surface to the lens of the third group  183 . 
   Similar to the fourteenth embodiment, it is preferable for the zoom lens of this embodiment that the conditional expressions (8)-(16) are satisfied. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 70. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 70 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               35.243 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               18.353 
               5.25 
               1.60311 
               60.7 
             
             
                 
               3 
               −154.339 
               0.15 
             
             
                 
               4 
               17.449 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               53.989 
               Variable 
             
             
               2 
               6 
               53.989 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               5.142 
               2.97 
             
             
                 
               8 
               −7.948 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               5.519 
               2.70 
               1.80518 
               25.4 
             
             
                 
               10 
               1291.253 
               Variable 
             
             
               3 
               11 
               13.124 
               2.40 
               1.43425 
               95.0 
             
             
                 
               12 
               −23.353 
               2.70 
             
             
               4 
               13 
               −45.406 
               0.60 
               1.58913 
               61.2 
             
             
                 
               14 
               24.428 
               1.50 
               1.80528 
               25.4 
             
             
                 
               15 
               36.015 
               Variable 
             
             
               5 
               16 
               −69.769 
               0.60 
               1.84666 
               23.9 
             
             
                 
               17 
               18.397 
               2.70 
               1.51633 
               64.1 
             
             
                 
               18 
               −13.178 
               0.10 
             
             
                 
               19 
               11.587 
               2.95 
               1.51450 
               63.1 
             
             
                 
               20 
               −21.551 
               Variable 
             
             
               6 
               21 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               22 
               ∞ 
               2.80 
               1.51633 
               64.1 
             
             
                 
               23 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 71 shows aspherical coefficients of the zoom lens in the present example. 
   
     
       
         
             
             
           
             
                 
               TABLE 71 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               19 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −4.89985 
               −6.72168 
               −1.37149 × 10 +1   
               −6.00589 × 10 −1   
             
             
               D 
               −1.08175 × 10 −3   
                3.03174 × 10 −4   
                8.68352 × 10 −6   
               −5.27645 × 10 −5   
             
             
               E 
               −1.06040 × 10 −5   
               −9.85138 × 10 −7   
                2.15192 × 10 −6   
               −3.20955 × 10 −7   
             
             
                 
             
          
         
       
     
   
   The following Table 72 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position, magnification of the second lens group  182  becomes −1 times in Table 72. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 72 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.690 
               18.643 
               42.802 
             
             
                 
               F/NO 
               1.661 
               1.872 
               2.077 
             
             
                 
               2ω 
               58.504 
               11.814 
               5.116 
             
             
                 
               d5 
               0.600 
               11.675 
               14.927 
             
             
                 
               d10 
               17.903 
               6.827 
               3.575 
             
             
                 
               d14 
               5.200 
               2.299 
               5.200 
             
             
                 
               d19 
               1.000 
               3.901 
               1.000 
             
             
                 
                 
             
          
         
       
     
   
   The values of the expressions (8) to (14) are as follows.
 
 rS 1/ rS 9=1.02  (eleventh plane)
 
 rS 1/ rS 9=0.26  (twelfth plane)
 
| f 3/ f 34|=0.60
 
 BF/fw= 3.60
 
 f 1/ fw= 6.98
 
| f 2|/ fw= 1.25
 
 f 34/ fw= 8.93
 
 f 5/ fw= 3.36
 
     FIGS. 83-85  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. As clearly shown in the aberrations of  FIGS. 83-85 , a zoom lens according to this embodiment has sufficient performance to correct aberration to obtain high resolution of a zoom lens. 
   Twentieth Embodiment 
     FIG. 86  is a view showing the arrangement of a zoom lens in a twentieth embodiment according to the present invention. As shown in  FIG. 86 , a zoom lens has a structure in which a first lens group  221 , a second lens group  222 , a third lens group  223 , a fourth lens group  224 , and a fifth lens group  225  are disposed from an object side (left side in  FIG. 86 ) to an image plane side (right side in  FIG. 86 ) in this order. 
   The first lens group  221  has a positive refracting power and is fixed with respect to the image plane in varying power and at focusing. The second lens group  222  has a negative refracting power and varies power by moving along the optical axis. The third lens group  223  is composed of two lenses: a positive lens and a negative lens disposed from the object side in this order, and this group has a positive refracting power as a whole. 
   The fourth lens group  224  is composed of two lenses: a positive lens and a negative lens disposed from the object side in this order and this group has a negative refracting power as a whole, and is fixed with respect to the image plane in varying power and focusing. 
   The fifth lens group  225  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  223  vertically with respect to the optical axis. 
   The performance when shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the third group  223 . 
   Similar to the fourteenth embodiment, it is preferable for the zoom lens of this embodiment that the conditional expressions (8)-(16) are satisfied. Specific examples of zoom lenses according to this embodiment are shown in the following Table 73. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 73 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               35.243 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               18.353 
               5.25 
               1.60311 
               60.7 
             
             
                 
               3 
               −154.339 
               0.15 
             
             
                 
               4 
               17.449 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               53.989 
               Variable 
             
             
               2 
               6 
               53.989 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               5.142 
               2.97 
             
             
                 
               8 
               −7.948 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               5.519 
               2.70 
               1.80518 
               25.4 
             
             
                 
               10 
               1291.253 
               Variable 
             
             
               3 
               11 
               13.385 
               2.45 
               1.51450 
               63.1 
             
             
                 
               12 
               −17.352 
               0.60 
             
             
                 
               13 
               −120.265 
               1.00 
               1.84666 
               25.4 
             
             
                 
               14 
               68.318 
               2.70 
             
             
               4 
               15 
               −18.144 
               1.50 
               1.58913 
               61.2 
             
             
                 
               16 
               −15.906 
               1.00 
               1.80518 
               25.4 
             
             
                 
               17 
               −22.792 
               1.00 
             
             
                 
               19 
               39.750 
               Variable 
             
             
               5 
               20 
               −47.899 
               0.60 
               1.84666 
               23.9 
             
             
                 
               21 
               23.192 
               2.70 
               1.51633 
               64.1 
             
             
                 
               22 
               −12.941 
               0.10 
             
             
                 
               23 
               10.762 
               2.95 
               1.51450 
               63.1 
             
             
                 
               24 
               −21.804 
               Variable 
             
             
               6 
               25 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               26 
               ∞ 
               2.80 
               1.51633 
               64.1 
             
             
                 
               27 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 74 shows aspherical coefficients of the zoom lens in the present example. 
   
     
       
         
             
             
           
             
                 
               TABLE 74 
             
           
          
             
                 
                 
             
             
                 
               Surface 
             
          
         
         
             
             
             
             
             
          
             
                 
               8 
               11 
               12 
               23 
             
             
                 
                 
             
          
         
         
             
             
             
             
             
          
             
               K 
               −4.89985 
               −5.91060 
               −5.50770 
               −7.58012 × 10 −1   
             
             
               D 
               −1.08175 × 10 −3   
                1.96402 × 10 −4   
               −2.82483 × 10 −5   
               −5.38373 × 10 −5   
             
             
               E 
               −1.06040 × 10 −5   
               −1.63114 × 10 −6   
                3.84825 × 10 −6   
               −2.44675 × 10 −7   
             
             
                 
             
          
         
       
     
   
   The following Table 75 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position, magnification of the second lens group  222  becomes −1 times in Table 75. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 75 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.685 
               17.981 
               42.743 
             
             
                 
               F/NO 
               1.728 
               1.936 
               2.074 
             
             
                 
               2ω 
               58.590 
               12.248 
               5.113 
             
             
                 
               d5 
               0.600 
               11.675 
               14.927 
             
             
                 
               d10 
               17.903 
               6.827 
               3.575 
             
             
                 
               d14 
               5.200 
               2.360 
               5.200 
             
             
                 
               d19 
               1.000 
               3.840 
               1.000 
             
             
                 
                 
             
          
         
       
     
   
   The values of the expressions (8) to (14) are as follows.
 
 rS 1/ rS 9=1.05
 
 rS 1/ rS 9=0.46
 
| f 3/ f 34|=0.62
 
 BF/fw= 3.58
 
 f 1/ fw= 6.99
 
| f 2|/ fw= 1.25
 
 f 34/ fw= 8.79
 
 f 5/ fw= 3.25
 
     FIGS. 87-89  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. As clearly shown in the aberrations of  FIGS. 87-89 , a zoom lens according to this embodiment has sufficient performance to correct aberration to realize high resolution. 
   Twenty-First Embodiment 
     FIG. 90  is a view showing the arrangement of a zoom lens in a twenty-first embodiment according to the present invention. As shown in  FIG. 90 , a zoom lens has a structure in which a first lens group  261 , a second lens group  262 , a third lens group  263 , a fourth lens group  264 , and a fifth lens group  265  are disposed from an object side deft side in  FIG. 90 ) to an image plane side (right side in  FIG. 90 ) in this order. 
   The first lens group  261  has a positive refracting power and is fixed with respect to the image plane in varying power and focusing. The second lens group  262  has a negative refracting power and varies power by moving along an optical axis. The third lens group  263  is composed of two lenses: a positive lens and a negative lens disposed from the object side in this order, and this group has a positive refracting power as a whole. 
   The fourth lens group  264  is composed of two lenses: a negative lens and a positive lens disposed from the object side in this order and this group has a negative refracting power as a whole, and is fixed with respect to the image plane in varying power and focusing. The fifth lens group  265  has a positive refracting power and moves along an optical axis so as to move an image and adjust the focus thereof at the same time in accordance with variable power. When camera shake occurs, shake of an image is corrected by moving the third lens group  263  vertically with respect to the optical axis. 
   The performance when shifting the lenses can be improved by applying at least one aspherical surface to any of the lenses of the third group  263 . 
   Similar to the fourteenth embodiment, it is preferable for the zoom lens of this embodiment that the conditional expressions (8)-(16) are satisfied. 
   Specific examples of zoom lenses according to this embodiment are shown in the following Table 76. 
   
     
       
         
             
             
             
             
             
             
           
             
               TABLE 76 
             
             
                 
             
             
               Group 
               Surface 
               r 
               d 
               n 
               ν 
             
             
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
             
          
             
               1 
               1 
               35.243 
               0.90 
               1.80518 
               25.4 
             
             
                 
               2 
               18.353 
               5.25 
               1.60311 
               60.7 
             
             
                 
               3 
               −154.339 
               0.15 
             
             
                 
               4 
               17.449 
               3.00 
               1.60311 
               60.7 
             
             
                 
               5 
               53.989 
               Variable 
             
             
               2 
               6 
               53.989 
               0.70 
               1.78500 
               43.7 
             
             
                 
               7 
               5.142 
               2.97 
             
             
                 
               8 
               −7.948 
               0.80 
               1.66547 
               55.2 
             
             
                 
               9 
               5.519 
               2.70 
               1.80518 
               25.4 
             
             
                 
               10 
               1291.253 
               Variable 
             
             
               3 
               11 
               13.379 
               2.45 
               1.51450 
               63.1 
             
             
                 
               12 
               −14.156 
               0.60 
             
             
                 
               13 
               −61.508 
               1.00 
               1.80518 
               25.4 
             
             
                 
               14 
               64.122 
               2.70 
             
             
               4 
               17 
               −28.305 
               1.00 
               1.51633 
               61.2 
             
             
                 
               18 
               24.977 
               1.60 
             
             
                 
               19 
               19.641 
               1.50 
               1.80518 
               25.4 
             
             
                 
               20 
               25.463 
               Variable 
             
             
               5 
               21 
               −54.314 
               0.60 
               1.84666 
               23.9 
             
             
                 
               22 
               24.366 
               2.70 
               1.51633 
               64.1 
             
             
                 
               23 
               −13.009 
               0.10 
             
             
                 
               24 
               11.183 
               2.95 
               1.51450 
               63.1 
             
             
                 
               25 
               −21.825 
               Variable 
             
             
               6 
               26 
               ∞ 
               14.00 
               1.58913 
               61.2 
             
             
                 
               27 
               ∞ 
               2.80 
               1.51633 
               64.1 
             
             
                 
               28 
               ∞ 
               — 
             
             
                 
             
          
         
       
     
   
   The following Table 77 shows aspherical coefficients of the zoom lens in the present embodiment. 
   
     
       
         
             
             
             
           
             
                 
               TABLE 77 
             
           
          
             
                 
                 
             
             
                 
               Surface 
                 
             
          
         
         
             
             
             
             
          
             
                 
               8 
               13 
               22 
             
             
                 
                 
             
          
         
         
             
             
             
             
          
             
               K 
               −4.89985 
               −8.46317 
               −1.14637 
             
             
               D 
               −1.08175 × 10 −3   
                1.00945 × 10 −4   
               −6.03706 × 10 −5   
             
             
               E 
               −1.06040 × 10 −5   
               −1.63114 × 10 −6   
               −8.33884 × 10 −8   
             
             
                 
             
          
         
       
     
   
   The following Table 78 shows an air distance (mm) that is varied by zooming in the case where an object is positioned 2 m away from the tip end of the lens. At the standard position, magnification of the second lens group  262  becomes −1 times in Table 78. 
   
     
       
         
             
             
             
             
           
             
                 
               TABLE 78 
             
             
                 
                 
             
             
                 
               Wide-angle end 
               Standard position 
               Telephoto end 
             
             
                 
                 
             
           
          
             
                 
             
          
         
         
             
             
             
             
             
          
             
                 
               f 
               3.684 
               18.016 
               42.724 
             
             
                 
               F/NO 
               1.676 
               1.898 
               2.073 
             
             
                 
               2ω 
               58.536 
               12.215 
               5.106 
             
             
                 
               d5 
               0.600 
               11.675 
               14.927 
             
             
                 
               d10 
               17.903 
               6.827 
               3.575 
             
             
                 
               d14 
               5.200 
               2.343 
               5.200 
             
             
                 
               d19 
               1.000 
               3.857 
               1.000 
             
             
                 
                 
             
          
         
       
     
   
   The values of the Expressions (8) to (14) are as follows.
 
 rS 1/ rS 9=0.93
 
 rS 1/ rS 9=0.63
 
| f 3/ f 34|=0.61
 
 BF/fw= 3.59
 
 f 1/ fw= 6.99
 
| f 2|/ fw 1.25
 
 f 34/ fw= 8.94
 
 f 5/ f= 3.26
 
     FIGS. 91-93  illustrate various aberrations at a wide-angle end, at a standard position and at a telephoto end of the zoom lens. As clearly shown in the aberrations of  FIGS. 91-93 , a zoom lens according to this embodiment has sufficient performance to correct aberration to realize high resolution. 
   Twenty-Second Embodiment 
     FIG. 94  is a view showing the arrangement of a video camera (three-plate-type video camera) in a twenty-second embodiment according to the present invention. As shown in  FIG. 94 , a video camera according to this embodiment comprises a zoom lens  301 , a low-pass filter  302 , prisms  303   a - 303   c  for color separation, imagers  304   a - 304   c , a signal processing circuit  305 , a view finder  306 , a sensor  307  for detecting camera shake, and an actuator  308  for driving the lens. The zoom lens of the fifteenth embodiment (see  FIG. 66 ) is used for the zoom lens  301 , and thus, a small and highly-qualified video camera having a function for correcting camera shake is realized. 
   In this embodiment, the zoom lens of  FIG. 66  in the fifteenth embodiment is used. This zoom lens can be replaced by any of the zoom lenses shown in the sixteenth to twenty-first embodiments. 
   Although camera shake is corrected by shifting a lens group having a positive refracting power, similar effects can be obtained by shifting a lens group having a negative refracting power. 
   INDUSTRIAL APPLICABILITY 
   As mentioned above, the present invention provides a zoom lens having a function to correct camera shake, i.e., a function to optically correct shake of an image caused by camera shake, vibration etc. The zoom lens can be made small and compact with less deterioration in the aberration performance. Such a zoom lens can be used as a zoom lens for a video camera or for an electronic still camera.