Fast aspherical zoom lens system

摘要

A fast aspherical zoom lens system includes a positive first lens group, a negative second lens group, a negative third lens group, and a positive fourth lens group, arranged in this order from the object side. The lens system includes at least one aspherical surface. When the zooming operation is carried out, the second and third lens groups are moved. The aspherical surface is located at a position in which the following condition is satisfied: HASP/HMAX<0.35, wherein HMAX represents the height of the paraxial ray furthest from the optical axis at the long focal length extremity for all the lens surfaces, and HASP represents the height of the paraxial ray to the aspherical surface at the long focal length extremity.