Patent ID: 7190529

Claim:
A zoom lens, comprising, in order from an object side thereof, a first lens group of positive refracting power, a second lens group of negative refracting power, a third lens group of positive refracting power, and a fourth lens group of positive refracting power, wherein: when a zoom lens system moves from a wide-angle end to a telephoto end thereof for zooming, a space between adjacent lens groups varies and the first lens group moves nearer to the object side at the telephoto end than at the wide-angle end, and the zoom lens system satisfies the following conditions: 5.7 <f 1 /f w <20 (1) 4.1 <M 2t /M 2w <15 (2) where f 1 is a focal length of the first lens group, f w is a focal length of the zoom lens system at the wide-angle end, M 2t is a transverse magnification of the second lens group at the telephoto end, and M 2w is a transverse magnification of the second lens group at the wide-angle end.