Patent ID: 7522350

Claim:
A zoom lens system comprising: a first lens unit having a negative optical power, the first lens unit including a single negative lens element and a single positive lens element; and a second lens unit having a positive optical power, wherein the first lens unit and the second lens unit are arranged in that order from an object side to an image side, wherein a distance between the first lens unit and the second lens unit at a telephoto end is smaller than that at a wide angle end, and wherein, when v 1 p is an Abbe number of a material of the positive lens element, f 1 is a focal length of the first lens unit, fw is a focal length of the entire zoom lens system at the wide angle end, and N 1 n and v 1 n are a refractive index and an Abbe number, respectively, of the material of the negative lens element, the following conditions are satisfied: v1p<18.5 2.0 <|f 1|/ fw< 2.8 1.83<N1n, and 27<v1n.