Patent ID: 7515353
Filing Date: 2009-04-07
Classification: G02B

Abstract:
1. A zoom lens system comprising, in order from an object side to an image side: a first lens unit having a positive optical power; a second lens unit having a negative optical power, the second lens unit being movable so that a distance between the first lens unit and the second lens unit at a telephoto end is greater than that at a wide-angle end; and a rear lens component including at least one lens unit, wherein the second lens unit includes a negative lens element made of a material satisfying the first conditions: where Nd is an index of refraction of the material for the d-line, and νd is the Abbe number expressed by: where NF is an index of refraction of the material for the F-line, and NC is an index of refraction of the material for the C-line.