Patent ID: 7589910

Claim:
A zoom lens, comprising: a first lens group having a negative refracting power; a second lens group having a positive refracting power; a third lens group having a positive refracting power, the first lens group, the second lens group and the third lens group disposed in order from an object side; and an aperture stop disposed on the object side of the second lens group, moving with the second lens group, wherein along with changing magnification from a wide-angle end toward a telephoto end, at least the first lens group and the second lens group move, in a manner that a spacing between the first lens group and the second lens group decreases and a spacing between the second lens group and the third lens group increases, and the second lens group, comprising: a first cemented lens having at least three pieces of lenses united; and a second cemented lens having at least two pieces of lenses united.