Patent ID: 8320053

Claim:
A zoom lens comprising, in a sequence from an object side: a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a succeeding lens group having an overall positive refractive power, wherein: during zooming from a wide angle position to a telephoto position, an interval between the first lens group and the second lens group increases, and an interval between the second lens group and the succeeding lens group decreases; the first lens group comprises at least one negative lens and at least three positive lenses, and the second lens group comprises, in a sequence from the object side, a front group having a negative refractive power and a rear group having a positive refractive power; and the zoom lens satisfies at least one of the following expressions: 0 <R 2 al/R 2 bf< 1; and 0.01 <R 2 al/ft< 0.25, where R 2 al denotes a radius of curvature of a lens closest to an image side in the front group of the second lens group, R 2 bf denotes a radius of curvature of a lens closest to the object side in the rear group of the second lens group, and ft denotes an overall focal length of the zoom lens at the telephoto position.