Abstract:
A zoom lens system including: a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group and a fourth lens group having positive refractive power, wherein an interval between the first and second lens groups, an interval between the second and third lens groups, and an interval between the third and fourth lens groups change during zooming from a wide-mode to a tele-mode, wherein the first lens group comprises one negative lens and three positive lenses sequentially from the object to the image, wherein the zoom lens system satisfies an condition below: 
       0.8&lt; f   13   /f   14 &lt;1, and 
     wherein f 13  denotes a focal length of a positive lens of the first lens group disposed second from the image to the object, and f 14  denotes a focal distance of a positive lens of the first lens group disposed closest to the image.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application claims priority from Korean Patent Application No. 10-2012-0085395, filed on Aug. 3, 2012, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in by reference its entirety. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    Apparatuses consistent with exemplary embodiments relate to a zoom lens and a photographing apparatus including the same. 
         [0004]    2. Description of the Related Art 
         [0005]    As a solid image capturing device such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) becomes smaller and still realizes a high pixel resolution, a lens system included in an image forming device such as a digital camera, a video camera, and a surveillance camera including the image capturing device is also required to have improved optical performance and become smaller. 
         [0006]    Also, the number of digital camera and surveillance camera users have increased and become more sophisticated with such devices, demand for photographing apparatuses that implement a high magnification and excellent optical performance is increasing. Accordingly, zoom lenses employed in digital cameras and surveillance cameras are required to have high performance and magnification, and be small and lightweight at the same time. 
         [0007]    In the related art, since four group type zoom lenses are suitable for achieving 5x or higher magnifications and are relatively small, the constructions of the four group type zoom lenses are suitable to satisfy the above demand, and thus, the four group type zoom lenses are being employed in photographing apparatuses. 
         [0008]    Accordingly, various four group type zoom lens designs have been proposed. However, aberration accompanying zooming still increases in the proposed designs when trying to achieve high magnification, and the aberration makes it difficult to realize high optical performance throughout the overall region while switching from a wide-mode to a tele-mode. 
       SUMMARY 
       [0009]    One or more exemplary embodiments provide a zoom lens system that achieves high magnification and has high optical performance, and a photographing apparatus including the zoom lens system 
         [0010]    One or more exemplary embodiments also provide a zoom lens system that achieves miniaturization and obtains a sufficient back focal distance, and a photographing apparatus including the zoom lens system. 
         [0011]    According to an aspect of an exemplary embodiment, there is provided a zoom lens system including, sequentially from an object to an image: a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having positive refractive power, wherein an interval between the first lens group and the second lens group, an interval between the second lens group and the third lens group, and an interval between the third lens group and the fourth lens group change during zooming from a wide-mode to a tele-mode, wherein the first lens group includes one negative lens and three positive lenses sequentially from the object to the image, wherein the zoom lens system satisfies an condition below: 
         [0000]      0.8&lt; f   13   /f   14 &lt;1, and 
         [0012]    wherein f 13  denotes a focal length of a positive lens of the first lens group disposed second from the image to the object, and f 14  denotes a focal distance of a positive lens of the first lens group disposed closest to the image. 
         [0013]    The zoom lens system may satisfy a condition below: 
         [0000]      4.8&lt; f   G3   /f   t &lt;6.5 
         [0014]    wherein f G3  denotes a focal length of the third lens group and f t  denotes an overall focal length at the tele-mode. 
         [0015]    The zoom lens system may satisfy a condition below: 
         [0000]      41.5 &lt;f   t   /f   w &lt;44.5 
         [0016]    wherein f t  denotes an overall focal length at the tele-mode, and f w  denotes an overall focal length at the wide-mode. 
         [0017]    The zoom lens system may satisfy a condition below: 
         [0000]      Fno w &lt;1.5 
         [0000]    wherein Fno w  denotes an F number at the wide-mode. 
         [0018]    The third lens group may include a positive lens and a negative lens, wherein the positive lens includes at least one aspheric surface. 
         [0019]    During the zooming from the wide-mode to the tele-mode, the second and fourth lens groups may move along an optical axis and the first and third lens groups may be fixed. 
         [0020]    The zoom lens system may further include an aperture disposed between the second lens group and the third lens group. 
         [0021]    The second lens group may include two negative lenses and one positive lens sequentially from the object to the image. 
         [0022]    At least one of the two negative lenses included in the second lens group may include an aspheric surface. 
         [0023]    The second lens group may include three negative lenses and one positive lens sequentially from the object to the image. 
         [0024]    A negative lens and the positive lens that are included in the second lens group and disposed closest to the image may form a cemented lens. 
         [0025]    The fourth lens group may include a positive lens and a negative lens sequentially from the object to the image. 
         [0026]    The positive lens included in the fourth lens group may satisfy a condition below: 
         [0000]      Nd 41 &lt;1.56 
         [0000]    wherein Nd 41  denotes a refractive index of the positive lens included in the fourth lens group. 
         [0027]    The positive lens included in the fourth lens group may include at least one aspheric surface. 
         [0028]    The fourth lens group may include one negative lens and two positive lenses sequentially from the object to the image. 
         [0029]    The negative lens included in the fourth lens group may include at least one aspheric surface. 
         [0030]    The interval between the first lens group and the second lens group increases, the interval between the second lens group and the third lens group decreases, and the interval between the third lens group and the fourth lens group changes during the zooming from the wide-mode to the tele-mode, 
         [0031]    The interval between the third lens group and the fourth lens group increases and decreases during the zooming from the wide-mode to the tele-mode. 
         [0032]    According to another aspect of the present invention, there is provided a photographing apparatus including: the zoom lens system; and an image sensor which receives light from the zoom lens system. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0033]    The above and/or other features and advantages will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
           [0034]      FIG. 1  is a diagram of an optical arrangement of a zoom lens system according to a first exemplary embodiment; 
           [0035]      FIG. 2  illustrates longitudinal spherical aberration, astigmatic field curves, and distortion of the zoom lens system of  FIG. 1 ; 
           [0036]      FIG. 3  illustrates lateral aberration of the zoom lens system of  FIG. 1 ; 
           [0037]      FIG. 4  is a diagram of an optical arrangement of a zoom lens system according to a second exemplary embodiment; 
           [0038]      FIG. 5  illustrates longitudinal spherical aberration, astigmatic field curves, and distortion of the zoom lens system of  FIG. 4 ; 
           [0039]      FIG. 6  illustrates lateral aberration of the zoom lens system of  FIG. 4 ; 
           [0040]      FIG. 7  is a diagram of an optical arrangement of a zoom lens system according to a third exemplary embodiment; 
           [0041]      FIG. 8  illustrates longitudinal spherical aberration, astigmatic field curves, and distortion of the zoom lens system of  FIG. 7 ; 
           [0042]      FIG. 9  illustrates lateral aberration of the zoom lens system of  FIG. 7 ; and 
           [0043]      FIG. 10  is a schematic perspective view of a photographing apparatus including the zoom lens system of  FIG. 1  according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0044]    Hereinafter, exemplary embodiments will be described in detail with reference to the attached drawings. In the drawings, like reference numerals in the drawings denote like elements, and the size of each component may be exaggerated for clarity. 
         [0045]      FIGS. 1 ,  4 , and  7  are diagrams of an optical arrangement of zoom lens systems  100 ,  200 , and  300 , respectively, according to first, second and third exemplary embodiments. 
         [0046]    The zoom lens systems  100 ,  200 , and  300  according to the first, second and third exemplary embodiments of  FIGS. 1 ,  4 , and  7 , respectively, include a first lens group G 1  having positive refractive power, a second lens group G 2  having negative refractive power, a third lens group G 3  having positive refractive power, and a fourth lens group G 4  having positive refractive power in an order from an object O side to an image I side. Also, an aperture ST is disposed between the second lens group G 2  and the third lens group G 3 , and an optical block G is disposed between the fourth lens group G 4  and an image plane IP. 
         [0047]    In the zoom lens systems  100 ,  200 , and  300 , an interval between the first lens group G 1  and the second lens group G 2  increases, an interval between the second lens group G 2  and the third lens group G 3  decreases, and an interval between the third lens group G 3  and the fourth lens group G 4  both decreases and increases during zooming from a wide-mode to a tele-mode. The first lens group G 1  and the third lens group G 3  may maintain a fixing state, and perform zooming when the second lens group G 2  and the fourth lens group G 4  move along an optical axis. During zooming from the wide-mode to the tele-mode, the second lens group G 2  may move from the object O toward the image I, and the fourth lens group G 4  may move from the image I toward the object O and back again toward the image I. 
         [0048]    The first lens groups G 1  in the zoom lens systems  100 ,  200 , and  300  may include four lenses including one negative lens L 11 , L 11 ′, and L 11 ″, respectively, and three positive lenses L 12 , L 13 , L 14 , L 12 ′, L 13 ′, L 14 ′, L 12 ″, L 13 ″ L 14 ″, respectively, in an order from the object O to the image I. The negative lenses L 11 , L 11 ′, and L 11 ″ included in the first lens group G 1  may have a convex meniscus shape on a side toward the object O near the optical axis. The positive lenses L 12 , L 12 ′, and L 12 ″ disposed on a side toward the object O may have bi-convex shapes. The two positive lenses L 13 , L 13 ′, L 13 ″, L 14 , L 14 ′, and L 14 ″ disposed on a side toward the image I may have convex shapes on a side toward the object O. The negative lens L 11 , L 11 ′, and L 11 ″ and the positive lenses L 12 , L 12 ′, and L 12 ″ disposed closest to the object O side may form cemented lenses. 
         [0049]    According to the above embodiments, the first lens group G 1  may appropriately disperse positive refractive power, thereby easily compensating for spherical aberration. Also, the positive lenses L 12 , L 12 ′, L 12 ″, L 13 , L 13 ′, L 13 ″, L 14 , L 14 ′, and L 14 ″ included in the first lens group G 1  may include materials having large dispersion values, thereby minimizing lateral chromatic aberration. 
         [0050]    The first lens group G 1  included in each of the zoom lens systems  100 ,  200 , and  300  according to the embodiments of the present invention may satisfy condition 1 below. 
         [0000]      0.8 &lt;f   13   /f   14 &lt;  [Condition 1]
 
         [0051]    In Condition 1, f 13  denotes a focal length of the positive lenses L 13 , L 13 ′, and L 13 ″ disposed second among the three positive lenses included in the first lens group G 1  from the image I side to the object O side, and f 14  denotes a focal distance of the positive lenses L 14 , L 14 ′, and L 14 ″ disposed closest to the image I side. 
         [0052]    Condition 1 above represents a ratio of an appropriate focal distance between the two positive lenses (i.e L 13  and L 14 , L 13 ′ and L 14 ′, and L 13 ″ and L 14 ″) included in the first lens group G 1  and disposed in the image I. In Condition 1, if the ratio exceeds an upper limit, it is difficult to effectively compensate for chromatic aberration in the tele-mode, and if the ratio is below a lower limit, an overall size of the first lens group G 1  increases, which makes it difficult to miniaturize the first lens group G 1 . 
         [0053]    From the object O side toward the image I side, the second lens group G 2  includes two negative lenses L 21 , L 21 ″, L 22 , and L 22 ″ and one positive lens L 23  and L 23 ″. At least one of the negative lenses L 21 , L 21 ″, L 22 , and L 22 ″ included in the second lens group G 2  may include one aspheric surface. 
         [0054]    In another embodiment as shown in  FIG. 4 , the second lens group G 2  may include three negative lenses L 21 ′, L 22 ′, and L 231 ′ and one positive lens L 232 ′. The negative lens L 231 ′ and the positive lens L 232 ′ of the second lens group G 2  may form a cemented lens L 23 ′, thereby easily compensating for chromatic aberration. 
         [0055]    The negative lenses L 21 , L 21 ′, and L 21 ″ included in the second lens group G 2  and disposed closest to the object O side may have meniscus shapes having convex surfaces on a side toward the object O side. The negative lenses L 22 , L 22 ′, and L 22 ″ disposed second from the object O side to the image I side may have bi-concave shapes. 
         [0056]    The second lens group G 2  may have negative refractive power as a whole, plays a greatest role in achieving high magnification of the zoom lens systems  100 ,  200 , and  300 , and moves from the object O side toward the image I side during zooming from the wide-mode to the tele-mode. 
         [0057]    In an order from the object O side to the image I side, the third lens group G 3  may include positive lenses L 31 , L 31 ′, and L 31 ″ having aspheric surfaces and negative lenses L 32 , L 32 ′, and L 32 ″ having meniscus shapes with convex surfaces on a side toward the object O. 
         [0058]    One surface or both surfaces of the positive lenses L 31 , L 31 ′, and L 31 ″ may be aspheric surfaces, thereby easily controlling aberration occurring on off-axis. 
         [0059]    In an order from the object O side to the image I side, the fourth lens group G 4  may include positive lenses L 41  and L 41 ″ having at least one aspheric surface and negative lenses L 41  and L 42 ″ having meniscus shapes with convex surfaces on a side toward the image I. The positive lenses L 41  and L 41 ″ and the negative lenses L 41  and L 42 ″ may form cemented lenses, thereby easily compensating for lateral chromatic aberration that may occur during zooming. 
         [0060]    The positive lenses L 41  and L 41 ″ included in the fourth lens group G 4  may satisfy Condition 2 below. 
         [0000]        Nd   41 &lt;1.56   [Condition 2]
 
         [0061]    In Condition 2, Nd 41  denotes a refractive index of the positive lenses L 41  and L 41 ″ included in the fourth lens group G 4 . In Condition 2, if the ratio exceeds an upper limit, it may be difficult to control comatic aberration. 
         [0062]    In another embodiment as shown in  FIG. 4 , the fourth lens group G 4  may include one negative lens L 41 ′ having at least one aspheric surface and two positive lenses L 42 ′ and L 43 ′. The negative lens L 41 ′ and the positive lens L 42 ′ disposed on a side toward the object O may form a cemented lens. 
         [0063]    The aperture ST may be disposed between the second lens group G 2  and the third lens group G 3 . The optical block G is disposed between the fourth lens group G 4  and the image plane IP. The optical block G may be an optical filter such as a low pass filter (LPF) or an infrared ray (IR) cut filter or cover glass (CG) for protecting image capturing surface of an image capturing device. 
         [0064]    Also, the zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments may satisfy Condition 3 below. 
         [0000]      4.8&lt; f   G3   /f   t &lt;6.5   [Condition 3]
 
         [0065]    In Condition 3, f G3  denotes a focal distance of the third lens group G 3 , and f t  denotes an overall focal distance in the tele-mode. 
         [0066]    Condition 3 above represents an appropriate range of a ratio of the focal distance of the third lens group G 3  with respect to the overall focal length in the tele-mode. In Condition 3, if the ratio is below 4.8, it may be difficult to control astigmatic aberration, and, if the ratio exceeds 6.5, it may be difficult to control comatic aberration. 
         [0067]    Also, the zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments may satisfy Conditions 4 and 5 below. 
         [0000]      41.5&lt; f   t   /f   w &lt;44.5   [Condition 4]
 
         [0000]      Fno w &lt;1.5   [Condition 5]
 
         [0068]    In Conditions 4 and 5, f t  denotes the overall focal distance in the telemode, f w  denotes an overall focal distance in the wide-mode, and Fno w  denotes an F number in the wide-mode. 
         [0069]    Condition 4 above represents a ratio of the overall focal distance in the tele-mode with respect to the overall focal distance in the wide-mode, i.e., an appropriate magnification range of the zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments. In Condition 4 above, if the ratio is below a lower limit, it may be difficult to achieve high magnification, and, if the ratio exceeds an upper limit, it may be difficult to control aberration, which deteriorates optical performance, and it may be difficult to achieve overall miniaturization of the zoom lens systems. 
         [0070]    Furthermore, Condition 5 above represents an appropriate range of the F number of the zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments. If the ratio exceeds an upper limit, it may be difficult to achieve a lens system achieving high optical performance. 
         [0071]    The zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments satisfy the above-described constructions and conditions, thereby achieving high magnification and high optical performance. Also, a miniaturized zoom lens system may be achieved, and a sufficient back focal length may be obtained. 
         [0072]    The construction of the zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments will be described in more detail with reference to specific lens data below. 
         [0073]    An aspheric surface ASP described throughout the embodiments of the present invention is defined below according to Equation 1. 
         [0000]    
       
         
           
             
               
                 
                   z 
                   = 
                   
                     
                       
                         ch 
                         2 
                       
                       
                         1 
                         + 
                         
                           
                             1 
                             - 
                             
                               
                                 ( 
                                 
                                   1 
                                   + 
                                   K 
                                 
                                 ) 
                               
                                
                               
                                 c 
                                 2 
                               
                                
                               
                                 h 
                                 2 
                               
                             
                           
                         
                       
                     
                     + 
                     
                       Ah 
                       4 
                     
                     + 
                     
                       Bh 
                       6 
                     
                     + 
                     
                       Ch 
                       8 
                     
                     + 
                     
                       Dh 
                       10 
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                      
                     
                         
                     
                      
                     1 
                   
                   ] 
                 
               
             
           
         
       
     
         [0074]    In Equation 1 above, z denotes a distance from a peak of a lens in the optical axis direction, h denotes a distance from the optical axis in the direction perpendicular to the optical axis direction, K denotes a conic constant, A, B, C, and D each denotes an aspheric coefficient, and c denotes an inverse number (1/R) of a radius of curvature at the peak of the lens. 
         [0075]    In the lens data of Tables 1, 4, and 7 below, Fno denotes an F-number, an effective focal length (EFL) denotes an overall EFL [mm] of the zoom lens system, and D 1 , D 2 , D 3 , and D 4  denote variable distances [mm] between lenses. 
         [0076]    Also, in design data of Tables 2, 5, and 8 below, R denotes a radius [mm] of curvature of each lens surface (however, a surface having ∞ as a value of R indicates a planar surface), D denotes an interval between lens surfaces in the optical axis direction, Nd denotes a refractive index of each lens, and Vd denotes an Abbe number of each lens. 
       First Embodiment  
       [0077]      FIG. 1  is a diagram of an optical arrangement of the zoom lens system  100  according to a first exemplary embodiment. In an order from the object O to the image I, the zoom lens system  100  of the present embodiment includes the first lens group G 1  having positive refractive power, the second lens group G 2  having negative refractive power, the third lens group G 3  having positive refractive power, and the fourth lens group G 4  having positive refractive power in an order from the object O to the image I. Also, the aperture ST is disposed between the second lens group G 2  and the third lens group G 3 , and the optical block G is disposed between the fourth lens group G 4  and the image plane IP. 
         [0078]    A reference numeral S i  of Table 2 indicates an ith surface when a surface of a lens disposed closest to the object O is a first surface S 1  and a surface number increases in a direction towards the image plane IP. This applies to the zoom lens systems  200  and  300  according to the other exemplary embodiments. 
         [0079]    Table 1 below shows the F number Fno, the focal distance f, and D 1 , D 2 , D 3 , and D 4  denote variable distances between lenses during zooming in the first embodiment. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 wide-mode 
                 middle-mode (1) 
                 middle-mode (2) 
                 tele-mode 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Fno 
                 1.42 
                 — 
                 — 
                 4.88 
               
               
                 f 
                 3.5 
                 — 
                 — 
                 150.6 
               
               
                 D1 
                 0.63 
                 12.346 
                 24.15 
                 26.573 
               
               
                 D2 
                 28.043 
                 16.327 
                 4.523 
                 2.1 
               
               
                 D3 
                 10.297 
                 6.939 
                 4.735 
                 16.836 
               
               
                 D4 
                 7.91 
                 11.268 
                 13.472 
                 1.371 
               
               
                   
               
             
          
         
       
     
         [0080]    Table 2 below shows design data of the first exemplary embodiment. 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                 TABLE 2 
               
               
                   
                   
               
               
                   
                 Surface No. 
                 R 
                 D 
                 Nd 
                 Vd 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 S1 
                 86.727 
                 1.20 
                 1.9108 
                 35.25 
               
               
                   
                 S2 
                 27.684 
                 7.69 
                 1.4970 
                 81.61 
               
               
                   
                 S3 
                 −226.838 
                 0.15 
               
               
                   
                 S4 
                 32.225 
                 5.23 
                 1.4970 
                 81.61 
               
               
                   
                 S5 
                 331.981 
                 0.15 
               
               
                   
                 S6 
                 26.894 
                 3.84 
                 1.4970 
                 81.61 
               
               
                   
                 S7 
                 71.833 
                 D1 
               
               
                   
                 S8* 
                 63.800 
                 0.64 
                 1.8513 
                 40.10 
               
               
                   
                 S9* 
                 5.378 
                 2.84 
               
               
                   
                 S10 
                 −11.258 
                 0.60 
                 1.8042 
                 46.50 
               
               
                   
                 S11 
                 12.156 
                 0.13 
               
               
                   
                 S12 
                 13.382 
                 1.86 
                 2.0027 
                 19.32 
               
               
                   
                 S13 
                 −119.000 
                 D2 
               
               
                   
                 ST 
                 Infinity 
                 0.40 
               
               
                   
                 S15* 
                 11.967 
                 3.26 
                 1.8014 
                 45.45 
               
               
                   
                 S16* 
                 −80.684 
                 2.16 
               
               
                   
                 S17 
                 18.485 
                 0.60 
                 2.0027 
                 19.32 
               
               
                   
                 S18 
                 9.288 
                 D3 
               
               
                   
                 S19* 
                 11.117 
                 3.83 
                 1.4971 
                 81.56 
               
               
                   
                 S20 
                 −7.624 
                 1.27 
                 1.8061 
                 40.73 
               
               
                   
                 S21 
                 −12.993 
                 D4 
               
               
                   
                 S22 
                 Infinity 
                 1.50 
                 1.5168 
                 64.20 
               
               
                   
                 S23 
                 Infinity 
                 2.02 
               
               
                   
                 IP 
                 Infinity 
                 0   
               
               
                   
                   
               
             
          
         
       
     
         [0081]    In Table 2 above, * denotes an aspheric surface. Table 3 below shows an aspheric surface coefficient of the first embodiment. E-m (where m is an integer) in a value of the aspheric surface coefficient denotes×10 −m . 
         [0000]    
       
         
               
               
             
               
               
               
               
               
               
             
           
               
                 TABLE 3 
               
             
             
               
                   
               
               
                 aspheric 
                   
               
               
                 surface 
                 Surface No. 
               
             
          
           
               
                 coefficient 
                 S8 
                 S9 
                 S15 
                 S16 
                 S19 
               
               
                   
               
               
                 K 
                   0.00E+00 
                   0.00E+00 
                   0.00E+00 
                   0.00E+00 
                 0.00E+00 
               
               
                 A 
                 0.184317E−03 
                 0.894468E−04 
                 −0.527935E−04  
                 0.443072E−04 
                 −0.156903E−03  
               
               
                 B 
                 −0.368864E−05  
                 0.214077E−04 
                 −0.231830E−06  
                 −0.211906E−08  
                 0.589350E−05 
               
               
                 C 
                 0.293634E−07 
                 −0.119346E−05  
                 0.419596E−08 
                 0.603431E−08 
                 −0.330602E−06  
               
               
                 D 
                 −0.258564E−09  
                 0.347176E−07 
                 0.745130E−10 
                 0.426997E−10 
                 0.764482E−08 
               
               
                   
               
             
          
         
       
     
         [0082]      FIG. 2  illustrates longitudinal spherical aberration, astigmatic field curves, and distortion of the zoom lens system  100  according to a first exemplary embodiment. 
         [0083]    A spherical aberration graph shows spherical aberration of light having wavelengths of 656.28 nm, 587.56 nm, 546.07 nm, 486.13 nm, and 435.84 nm. In an astigmatic field curve graph, a horizontal axis indicates a height of an image plane, and T and S indicate curves of light having a wavelength of 546.07 nm in a tangential surface and a sagittal surface, respectively. A distortion graph shows distortion of light having a wavelength of 546.07 nm. 
         [0084]      FIG. 3  illustrates lateral aberration, i.e., comatic aberration with respect to a height of an image plane, of the zoom lens system  100  according to the first exemplary embodiment, which shows aberration of light having wavelengths of 656.28 nm, 587.56 nm, 546.07 nm, 486.13 nm, and 435.84 nm in a tangential surface and a sagittal surface. 
       Second Embodiment  
       [0085]      FIG. 4  is a diagram of an optical arrangement of the zoom lens system  200  according to a second exemplary embodiment. The zoom lens system  200  of the present embodiment includes the first lens group G 1  having positive refractive power, the second lens group G 2  having negative refractive power, the third lens group G 3  having positive refractive power, and the fourth lens group G 4  having positive refractive power in an order from the object O to the image I. Also, the aperture ST is disposed between the second lens group G 2  and the third lens group G 3 , and the optical block G is disposed between the fourth lens group G 4  and the image plane IP. 
         [0086]    Table 4 below shows the F number Fno, the focal distance f, and D 1 , D 2 , D 3 , and D 4  denote variable distances between lenses during zooming in the second embodiment. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 4 
               
               
                   
                   
               
               
                   
                 wide-mode 
                 middle-mode (1) 
                 middle-mode (2) 
                 tele-mode 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Fno 
                 1.44 
                 — 
                 — 
                 4.89 
               
               
                 f 
                 3.5 
                 — 
                 — 
                 150.5 
               
               
                 D1 
                 0.6490 
                 12.6203 
                 25.2373 
                 27.9647 
               
               
                 D2 
                 29.1147 
                 17.1443 
                 4.5274 
                 1.7999 
               
               
                 D3 
                 7.7455 
                 4.7640 
                 2.8850 
                 15.3365 
               
               
                 D4 
                 7.7909 
                 10.7724 
                 12.6515 
                 0.2 
               
               
                   
               
             
          
         
       
     
         [0087]    Table 5 below shows design data of the second embodiment. 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                 TABLE 5 
               
               
                   
                   
               
               
                   
                 Surface No. 
                 R 
                 D 
                 Nd 
                 Vd 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 S1 
                 85.181 
                 0.80 
                 1.9108 
                 35.25 
               
               
                   
                 S2 
                 38.153 
                 6.24 
                 1.4970 
                 81.61 
               
               
                   
                 S3 
                 −237.553 
                 0.20 
               
               
                   
                 S4 
                 31.752 
                 4.11 
                 1.4970 
                 81.61 
               
               
                   
                 S5 
                 303.613 
                 0.20 
               
               
                   
                 S6 
                 25.841 
                 3.34 
                 1.4970 
                 81.61 
               
               
                   
                 S7 
                 81.591 
                 D1 
               
               
                   
                 S8* 
                 62.636 
                 0.50 
                 1.9108 
                 35.25 
               
               
                   
                 S9* 
                 6.918 
                 3.09 
               
               
                   
                 S10 
                 −22.553 
                 0.50 
                 1.9037 
                 31.32 
               
               
                   
                 S11 
                 71.328 
                 0.32 
               
               
                   
                 S12 
                 407.830 
                 0.50 
                 1.5298 
                 71.41 
               
               
                   
                 S13 
                 7.381 
                 2.38 
                 2.0027 
                 19.32 
               
               
                   
                 S14 
                 26.314 
                 D2 
               
               
                   
                 ST 
                 Infinity 
               
               
                   
                 S16* 
                 10.120 
                 3.08 
                 1.7323 
                 42.72 
               
               
                   
                 S17 
                 −140.955 
                 2.98 
               
               
                   
                 S18 
                 25.147 
                 0.50 
                 1.9229 
                 20.88 
               
               
                   
                 S19* 
                 9.705 
                 D3 
               
               
                   
                 S20 
                 12.211 
                 0.50 
                 1.8055 
                 32.36 
               
               
                   
                 S21 
                 8.821 
                 1.77 
                 1.5547 
                 70.30 
               
               
                   
                 S22 
                 19.957 
                 0.65 
               
               
                   
                 S23 
                 11.959 
                 2.62 
                 1.5311 
                 74.24 
               
               
                   
                 S24 
                 −14.948 
                 D4 
               
               
                   
                 S25 
                 Infinity 
                 2.54 
                 1.5168 
                 64.20 
               
               
                   
                 S26 
                 Infinity 
                 2.46 
               
               
                   
                 IP 
                 Infinity 
                 0   
               
               
                   
                   
               
             
          
         
       
     
         [0088]    In Table 5 above, * denotes an aspheric surface. Table 6 below shows an aspheric surface coefficient of the second embodiment. E-m (where m is an integer) in a value of the aspheric surface coefficient denotes×10 −m . 
         [0000]    
       
         
               
               
               
             
               
               
               
             
               
               
               
             
           
               
                 TABLE 6 
               
             
             
               
                   
               
               
                 aspheric 
                   
                   
               
               
                 surface 
                 Surface No. 
               
             
          
           
               
                 coefficient 
                 S16 
                 S20 
               
               
                   
               
             
          
           
               
                 K 
                 −0.841683 
                 −1.699651 
               
               
                 A 
                 −0.767072E−05 
                 −0.443275E−04 
               
               
                 B 
                 −0.109830E−06 
                 −0.450345E−06 
               
               
                 C 
                 0.442904E−09 
                 −0.656991E−08 
               
               
                 D 
                 0.000000E+00 
                 0.202662E−09 
               
               
                   
               
             
          
         
       
     
         [0089]      FIG. 5  illustrates longitudinal spherical aberration, astigmatic field curves, and distortion of the zoom lens system  200  according to the second exemplary embodiment. 
         [0090]    A spherical aberration graph shows spherical aberration of light having wavelengths of 656.28 nm, 587.56 nm, 546.07 nm, 486.13 nm, and 435.84 nm. In an astigmatic field curve graph, a horizontal axis indicates a height of an image plane, and T and S indicate curves of light having a wavelength of 546.07 nm in a tangential surface and a sagittal surface, respectively. A distortion graph shows distortion of light having a wavelength of 546.07 nm. 
         [0091]      FIG. 6  illustrates lateral aberration, i.e., comatic aberration with respect to a height of an image plane, of the zoom lens system  200  according to the second embodiment of the present invention, which shows aberration of light having wavelengths of 656.28 nm, 587.56 nm, 546.07 nm, 486.13 nm, and 435.84 nm in a tangential surface and a sagittal surface. 
       Third Embodiment  
       [0092]      FIG. 7  is a diagram of an optical arrangement of the zoom lens system  300  according to a third exemplary embodiment. The zoom lens system  300  of the present exemplary embodiment includes the first lens group G 1  having positive refractive power, the second lens group G 2  having negative refractive power, the third lens group G 3  having positive refractive power, and the fourth lens group G 4  having positive refractive power in an order from the object O to the image I. Also, the aperture ST is disposed between the second lens group G 2  and the third lens group G 3 , and the optical block G is disposed between the fourth lens group G 4  and the image plane IP. 
         [0093]    Table 7 below shows the F number Fno, the focal distance f, and the D 1 , D 2 , D 3 , and D 4  denote variable distances between lenses during zooming in the third exemplary embodiment. 
         [0000]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                 TABLE 7 
               
               
                   
               
               
                   
                 wide-mode 
                 middle-mode (1) 
                 middle-mode (2) 
                 tele-mode 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Fno 
                 1.4 
                 — 
                 — 
                 4.9 
               
               
                 f 
                 3.5 
                 — 
                 — 
                 150.5 
               
               
                 D1 
                 0.55 
                 12.7902 
                 25.5561 
                 27.8316 
               
               
                 D2 
                 28.8816 
                 16.6414 
                 3.8755 
                 1.6000 
               
               
                 D3 
                 9.5603 
                 6.8057 
                 6.3021 
                 16.9760 
               
               
                 D4 
                 7.5657 
                 10.3203 
                 10.8239 
                 0.15000 
               
               
                   
               
             
          
         
       
     
         [0094]    Table 8 below shows design data of the third embodiment. 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
               
             
           
               
                   
                 TABLE 8 
               
               
                   
                   
               
               
                   
                 Surface No. 
                 R 
                 D 
                 Nd 
                 Vd 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 S1 
                 84.535 
                 1.00 
                 1.9108 
                 35.25 
               
               
                   
                 S2 
                 35.017 
                 7.08 
                 1.4970 
                 81.61 
               
               
                   
                 S3 
                 −275.299 
                 0.15 
               
               
                   
                 S4 
                 34.096 
                 4.88 
                 1.4970 
                 81.61 
               
               
                   
                 S5 
                 285.75 
                 0.15 
               
               
                   
                 S6 
                 27.414 
                 3.61 
                 1.4970 
                 81.61 
               
               
                   
                 S7 
                 75.347 
                 D1 
               
               
                   
                 S8* 
                 38.655 
                 0.70 
                 1.8820 
                 37.22 
               
               
                   
                 S9* 
                 5.230 
                 3.27 
               
               
                   
                 S10 
                 −14.233 
                 0.50 
                 1.8042 
                 46.50 
               
               
                   
                 S11 
                 18.371 
                 0.15 
               
               
                   
                 S12 
                 12.804 
                 2.06 
                 2.0027 
                 19.32 
               
               
                   
                 S13 
                 −647.074 
                 D2 
               
               
                   
                 ST 
                 Infinity 
                 0.40 
               
               
                   
                 S15* 
                 13.294 
                 2.86 
                 1.8820 
                 37.22 
               
               
                   
                 S16* 
                 −71.961 
                 2.90 
               
               
                   
                 S17 
                 35.771 
                 0.50 
                 2.0027 
                 19.32 
               
               
                   
                 S18 
                 10.271 
                 D3 
               
               
                   
                 S19* 
                 11.856 
                 3.37 
                 1.5547 
                 60.71 
               
               
                   
                 S20 
                 −9.835 
                 1.00 
                 1.9459 
                 17.98 
               
               
                   
                 S21 
                 −12.984 
                 D4 
               
               
                   
                 S22 
                 Infinity 
                 2.54 
                 1.5168 
                 64.20 
               
               
                   
                 S23 
                 Infinity 
                 2.31 
               
               
                   
                 IP 
                 Infinity 
                 0   
               
               
                   
                   
               
             
          
         
       
     
         [0095]    In Table 8 above, * denotes an aspheric surface. Table 9 below shows an aspheric surface coefficient of the third embodiment. E-m (m is an integer) in a value of the aspheric surface coefficient denotes×10 −m . 
         [0000]    
       
         
               
               
             
               
               
               
               
             
           
               
                 TABLE 9 
               
             
             
               
                   
               
               
                 Aspheric 
                   
               
               
                 surface 
                 Surface No. 
               
             
          
           
               
                 coefficient 
                 S9 
                 S15 
                 S19 
               
               
                   
               
               
                 K 
                   0.00E+00 
                   0.00E+00 
                   0.00E+00 
               
               
                 A 
                 −0.970631E−04  
                 −0.677600E−04  
                 −0.194834E−03  
               
               
                 B 
                 0.710417E−05 
                 −0.334416E−06  
                 0.637960E−06 
               
               
                 C 
                 −0.365670E−06  
                 0.627489E−10 
                 −0.269615E−07  
               
               
                 D 
                   0.00E+00 
                   0.00E+00 
                   0.00E+00 
               
               
                   
               
             
          
         
       
     
         [0096]      FIG. 8  illustrates longitudinal spherical aberration, astigmatic field curves, and distortion of the zoom lens system  300  according to the third exemplary embodiment. 
         [0097]    A spherical aberration graph shows spherical aberration of light having wavelengths of 656.28 nm, 587.56 nm, 546.07 nm, 486.13 nm, and 435.84 nm. In an astigmatic field curve graph, a horizontal axis indicates a height of an image plane, and T and S indicate curves of light having a wavelength of 546.07 nm in a tangential surface and a sagittal surface, respectively. A distortion graph shows distortion of light having a wavelength of 546.07 nm. 
         [0098]      FIG. 9  illustrates lateral aberration, i.e., comatic aberration with respect to a height of an image plane, of the zoom lens system  300  according to the third exemplary embodiment, which shows aberration of light having wavelengths of 656.28 nm, 587.56 nm, 546.07 nm, 486.13 nm, and 435.84 nm in a tangential surface and a sagittal surface. 
         [0099]    Table 10 below shows that the above-described first, second and third exemplary embodiments satisfy the above-described conditions. 
         [0000]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
                 TABLE 10 
               
               
                   
                   
               
               
                   
                 First 
                 Second 
                 Third 
               
               
                   
                 Embodiment 
                 Embodiment 
                 Embodiment 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 0.8 &lt; f 13 /f 14  &lt; 1 
                 0.84 
                 0.96 
                 0.91 
               
               
                 4.8 &lt; f 3G /f t  &lt; 6.5 
                 6.11 
                 4.90 
                 4.94 
               
               
                 41.5 &lt; f t /f w  &lt; 44.5 
                 43.03 
                 43.00 
                 43.00 
               
               
                 Fno w  &lt; 1.5 
                 1.42 
                 1.44 
                 1.40 
               
               
                   
               
             
          
         
       
     
         [0100]    The zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments may have high optical performance while achieving high magnification. Also, bright and miniaturized zoom lens systems may be achieved, and a sufficient back focal distance may be obtained. 
         [0101]    The zoom lens systems  100 ,  200 , and  300  according to the exemplary embodiments may be applied as photographing optical systems of a photographing apparatus such as a surveillance camera including an image sensor, a digital camera, or a video camera. 
         [0102]      FIG. 10  is a schematic perspective view of a photographing apparatus  1  including the zoom lens system  100  according to an exemplary embodiment. 
         [0103]    The photographing apparatus  1  includes the zoom lens system  100  according to the first exemplary embodiment and an image sensor  20  that receives light formed by the zoom lens system  100 . 
         [0104]    The image sensor  20  may be a solid image capturing device such as a charge-coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) that receives light via the zoom lens system  100  and converts the light into an electrical signal. An image capturing surface of the image sensor  20  corresponds to the image plane IP of a zoom lens, 
         [0105]    The photographing apparatus  1  generates a digital image from the electrical signal, and records the digital image in a recording medium, for example, a hard disk drive (HDD), a memory card, an optical disk, a magnetic tape, etc. Meanwhile, in a case where the photographing apparatus  1  is a film camera, the image plane IP corresponds to a film surface. 
         [0106]    According to the exemplary embodiments, a zoom lens system that achieves high magnification and has high optical performance and a photographing apparatus including the zoom lens system may be provided. 
         [0107]    Also, a zoom lens system that achieves miniaturization and obtains a sufficient back focal distance and a photographing apparatus including the zoom lens system may be provided. 
         [0108]    While exemplary embodiments have been particularly shown and described above, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present inventive concept as defined by the following claims.