Patent ID: 7911707

Claim:
A zoom lens comprising, in order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; a third lens unit having a negative refractive power; and a fourth lens unit having a positive refractive power, wherein an interval between every adjacent ones of the first through fourth lens units varies during zooming, wherein the second lens unit includes at least one negative lens, wherein the third lens unit includes at least one positive lens, and wherein an Abbe number and a relative partial dispersion of a material of the at least one negative lens (νd2N, θgF2N) and an Abbe number and a relative partial dispersion of a material of the at least one positive lens (νd3P, θgF3P) satisfy the following conditions: 0.79<θ gF 2 N −(1.0×10 −4 ×νd 2 N 2 −9.1×10 −3 ×νd 2 N )<0.86 10<νd2N<30 0.79<θ gF 3 P −(1.0×10 −4 ×νd 3 P 2 −9.1×10 −3 ×νd 3 P )<0.86 10<νd3P<30.