The high varying magnification ratio zoom lens system null which includes the super compact wide angular

摘要

PURPOSE:To obtain a considerably compact zoom lens system of high performance by satisfying prescribed conditions in the lens system consisting of three groups which are arranged in order from the object side and have positive, negative, and positive refractive indexes respectively. CONSTITUTION:A first group I, a second group II, and a third group III are provided in order from the object side, and the third group III is divided into a front group III-F and a rear group III-B. In case of zooming from the short focal length end to the long focal length end, the first group I and front group III-F and the rear group III-B of the third group III are moved to the object side from the image surface side to change air intervals between the first and the second groups, between the second and the third groups, and between the front group III-F and the rear group III-B of the third group. The second group II consists of a first negative lens II-1 having a high curvature in the image side, a second negative lens II-2, a third positive lens II-3, and a fourth negative lens II-4 in order from the object side, and either lens in the third group III has an aspherical face, and conditions of inequalities I and II are satisfied.