| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a compact zoom lens having a high zoom ratio and high optical performance over the entire zoom range. <P>SOLUTION: The zoom lens comprises, in order from an object side to an image side: a first lens group having a positive refractive power; a second lens group having a negative refractive power; a third lens group having a positive refractive power; a fourth lens group having a negative refractive power; and a fifth lens group having a positive refractive power, in which each of the lens groups moves when zooming from a wide angle end to a telephoto end, the third lens group and the fifth lens group move as a unit when zooming, and an aperture stop is provided on the optical path of the fifth lens group. In the zoom lens, the third lens group or the fourth lens group moves when focusing. When the focal length of the second lens group is defined as f2, and the back focus at the wide angle end is defined as skw, the zoom lens satisfies the following conditional expression: 0.5<¾f2¾/skw<3.0. <P>COPYRIGHT: (C)2013,JPO&INPIT |
