Patent ID: 8125712
Filing Date: 2012-02-28
Classification: G02B

Abstract:
1. A zoom lens system consisting of, in order from an object side: a first lens group having negative refractive power; a second lens group having positive refractive power; upon varying a state of lens group positions from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group decreases, the first lens group consisting of, in order from the object side, a first lens having negative refractive power and a second lens having positive refractive power, the second lens group consisting of, in order from the object side, a third lens having positive refractive power, a fourth lens having negative refractive power, and a fifth lens having positive refractive power, at least a portion of the second lens group being movable in a direction substantially perpendicular to an optical axis, and the following conditional expression being satisfied: where fw denotes a focal length of the zoom lens system in the wide-angle end state, f1 denotes a focal length of the first lens group, and f2 denotes a focal length of the second lens group.