Patent ID: 9726865
Date: 2017-08-08
CPC Classifications: G02B

Claim:
1. A zoom lens system comprising a positive first lens group, a negative second lens group, a positive third lens group, a negative fourth lens group, and a positive fifth lens group, in that order from the object side, wherein, during zooming from the short focal length extremity to the long focal length extremity, at least said first lens group, said third lens group and said fifth lens group move in an optical axis direction thereof, wherein said fifth lens group includes a plurality of lens elements, wherein a surface closest to the image side of said zoom lens system is a concave surface facing the image side, and wherein the following condition (1) is satisfied: m345w designates the combined lateral magnification of said third lens group, said fourth lens group and said fifth lens group at the short focal length extremity when focused on an object at infinity, m345t designates the combined lateral magnification of said third lens group, said fourth lens group and said fifth lens group at the long focal length extremity when focused on an object at infinity, fw designates the focal length of said zoom lens system at the short focal length extremity, and ft designates the focal length of said zoom lens system at the long focal length extremity.