Patent ID: 7573649

Claim:
A high variable power zoom lens comprising four groups of component lens pieces, namely, a first lens group L 1 of positive refractivity closest to the subject, a second lens group L 2 of negative refractivity second closest to the subject, a third lens group L 3 of positive refractivity, and a fourth lens group L 4 of positive refractivity farthest from the subject, wherein the fourth lens group L 4 is fourth closest to the subject, and the fourth lens group L 4 includes a composite lens that has a convex lens piece and a concave meniscus lens piece bonded together, wherein the concave meniscus lens piece has a concave surface facing the subject, and the zoom lens satisfying requirements expressed in the following formula: 0.6≦| f 2|/ fW≦ 0.73 (1) 2.2≦ f 3 /fW≦ 3.7 (2) where f 2 is a focal length of the second lens group, f 3 is a focal length of the third lens group, and fW is a focal length of the entire optics in the wide-angle end position.