Patent ID: 7199941

Claim:
A zoom lens comprising: a first lens group having positive refraction, a second lens group having negative refraction, a third lens group having positive refraction, and a fourth lens group having positive fraction, being arrayed in this order from an object side, wherein, when a lens positional state changes from a wide-angle end condition to a telescopic end condition the first lens group and the third lens group are fixed in a predetermined position in an optical axis direction, as the second lens group moves towards an image side, fluctuation in an image position that is generated following a movement of the second lens group is compensated by a movement of the fourth lens group; wherein when the lens positional state changes, an aperture stop set in the optical axis direction is provided on an object side of the third lens group; and wherein the third lens group is constituted by a cemented lens including a positive lens wherein a convex surface thereof faces the object side and a negative lens in which a concave surface thereof faces the image side, and a positive lens, each being arrayed in this order from the object side.