Patent ID: 8760773

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 second lens group includes sequentially from the object side, a first lens that is a negative meniscus lens having a convex surface on the object side and having at least one aspheric surface, a negative second lens, a positive third lens, and a negative fourth lens, and the zoom lens satisfies: a conditional expression (1) 1.5<|f21/FW|<2.5, and a conditional expression (2) 0.5<|rp/f21|<0.8, where, f21 is a focal length of the first lens in the second lens group, FW is a focal length of the entire optical system at the wide angle edge, and rp is a radius of curvature of a surface on the image side of the first lens of the second lens group.