| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which offers high optical performance over an entire zoom range and an entire object distance range.SOLUTION: A zoom lens comprises a front group having one or more lens groups, a lens group Lp having positive refractive power, and a lens group Ln having negative refractive power arranged in order from the object side to the image side such that a distance between each pair of adjacent lens groups changes while zooming. The front group has a negative composite focal length at the wide-angle end. The lens group Lp moves toward the object side when zooming from the wide-angle end to the telephoto end. The lens group Ln moves toward the image side when shifting focus from infinity to a close distance at a first zoom position. When shifting focus from infinity to a close distance at a second zoom position located further on the telephoto end from the first zoom point, the lens group Lp moves toward the image side and the lens group Ln moves toward the object side. |
