Zoom taking lens for photographic or video camera - has two lens groups with positive and negative focal lengths movable relative to one another

摘要

The lens comprises a lens group with a positive focal length on the subject side and a lens group with a negative focal length on the image side. The zoom characteristic is obtained by varying the spacing between the groups. The first group has a positive meniscus with a convex surface on the subject side, a biconcave lens, a converging lens and a biconvex lens. The second lens group has a converging meniscus lens, a negative meniscus lens and a divergent meniscus lens, each having a convex surface on the image side. The optical characteristics of the lenses are defined by given equations. ADVANTAGE - Compact zoom lens with only 7 lens elements and wide field of view.