Cushman, Darby & Cushman
Finder optical system for cameras
 A finder optical system for single-lens reflex cameras comprising a screen on which an image by a photographing lens is to be formed through a half-mirror and a relay lens for forming the image formed on the screen in a focal position in front of a magnifying lens so that, when the focal distance of the magnifying lens is represented by f.sub.oc and the distance from the screen to the front principal point position of the magnifying lens is represented by L, the relation of 0.2.ltoreq.f.sub.oc /L.ltoreq.0.8 will satisfied, in order to make it easy to replace the photographing lens and to make the magnification high while keeping the eye point in a position sufficiently separated from the screen. 
Olympus Optical Co., Ltd.
G
G03B
inventional
Kazuo Toru
Ikari Fujii