Patent ID: 7800835

Claim:
A zoom lens comprising: a first lens group having a negative refractive power; and a second lens group having a positive refractive power, wherein the first lens group and the second lens group are disposed in that order from an object side to an image side, wherein, when magnification is changed between a wide-angle end and a telephoto end, the first lens group and the second lens group are moved in a direction of an optical axis, wherein the first lens group and the second lens group each include at least one plastic aspherical lens, and wherein the zoom lens satisfies the following Conditional Expressions (1) and (2), 0.40< fw/bkw< 0.60 (1) 0.01<|( X 1− X 0)/ h 0|<0.022 (2) where fw represents a focal length of the entire zoom lens which is in focus at infinity in a wide-angle end state; bkw represents back focus when the entire zoom lens is in focus at infinity in the wide-angle end state; X 1 represents a thickness at an image-side effective diameter position of the plastic aspherical lens of the first lens group; X 0 represents a thickness at the center of the plastic aspherical lens of the first lens group; and h 0 represents an image-side effective radius of the plastic aspherical lens of the first lens group.