Patent ID: 8693106

Claim:
A zoom lens comprises sequentially from an object side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a negative refractive power, wherein the first lens group, the third lens group, and the fifth lens group remain stationary, the second lens group is moved along an optical axis, from the object side toward an image side, whereby zooming from a wide angle edge to a telephoto edge is performed, the fourth lens group is moved along the optical axis, whereby image plane variation accompanying zooming is corrected and focusing is performed, the fifth lens group includes sequentially from the object side, a negative first lens having at least one aspheric surface and a positive second lens, and the zoom lens satisfies: a conditional expression (1) 1.5<|f51|/Y<3, and a conditional expression (2) 0.2<|F5/Ft|<0.8, where, f51 is a focal length of the first lens in the fifth lens group, Y is an image height for the entire optical system, F5 is a focal length of the fifth lens group, and Ft is a focal length of the entire optical system at the telephoto edge.