Patent ID: 7773312

Claim:
A zoom lens, comprising: a first lens group of negative refracting power; a second lens group of positive refracting power; and a third lens group of positive refracting power, wherein the first lens group, the second lens group and the third lens group are disposed in the following order from an object side of the zoom lens to an image side of the zoom lens: the first lens group, the second lens group and the third lens group, wherein the first lens group and the second lens group are configured to move during a zooming operation, and wherein, when a focal length of a system comprising the first lens group, the second lens group and the third lens group at a wide-angle end is denoted by fw, a focal length of the system at a telephoto end is denoted by fT, a focal length of the first lens group is denoted by f1, a focal length of the second lens group is denoted by f2, a focal length of the third lens group is denoted by f3, a lateral magnification of the second lens group at the wide-angle end is denoted by β2w, and a lateral magnification of the second lens group at the telephoto end is denoted by β2T, the following conditions: 0.00 <|f 1 /f 3|<0.45 1.0<|β2 w |/(1/√{square root over ((β2 T /β2 w )))}<1.5 0.00< f 2/√{square root over (( fw×fT ))}≦1.05 are satisfied.