Improved wide angle zoom objective lens system

Abstract

Abstract A wide angle zoom objective for all purposes comprising four lens components, of which first three components constitute a variable magnification system and the fourth constitutes a relay system. The second lens component which is movable is chosen negative, while other components are positive. Each of the first to third components includes a cemented lens of same sign as the lens component to which it belongs, and such cemented lens has a cemented surface of refractive power which is of the opposite sign to that of the lens component in which it is included. The focal lengths of the first to third lens components must be within specified range. The first and third components each comprises more than one positive lens group, and the second component includes more than one negative lens group and one positive lens group disposed rearmost from the front of the objective with a relatively large spacing from the negative lens groups thereof. The cemented surfaces in the first and second components are convex and concave, respectively, to the front of the objective. The cemented surfaces in the first to third lens components must have refractive power within specified limits. As to the second component, the spacing between the negative and positive groups, the focal length of the positive lens group and the radius of curvature of foremost surface in the positive group are within specified limits.

Inventors

• 👤 Tadashi Kojima

Bibliographic Details