| 摘要 |
A superwide-angle lens system includes a negative first lens group, an aperture diaphragm, and a positive second lens group. The first lens group includes two negative meniscus lens elements, and a positive lens element. The second lens group includes a cemented lens having negative and positive lens elements; and a positive lens element. The following conditions (1) and (2) are satisfied: −1.45<f12/f<−1.15  (1) 1.4<SF2<2.4  (2) f12: the combined focal length of the two the negative meniscus lens elements in the first lens group, f: the focal length of the lens system, SF2: the shaping factor of the negative meniscus lens element on the image side in the first lens group. |
