GB454064A - Improvements in or relating to photographic cameras - Google Patents

Abstract

454,064. View-finders and telemeters for photographic cameras. LEITZ GES., E., Optical Works, Wetzlar, Germany. Dec. 24, 1935, Nos. 35696 and 35697. Convention dates, Jan. 31 and Nov. 11. Addition to 454,063. [Class 98 (i)] In a photographic camera, a short-homebase telemeter is combined with a view-finder comprising a concave reflector in the form of an opaque or nearly opaque frame surrounding a transparent area through which the telemeter rays can pass to the viewing opening, the reflecting frame being such as to reproduce substantially at infinity a frame-like mark surrounding the image field adjacent to the viewing opening. As shown, the camera J has a casing K containing the telemeter and a casing H containing the view-finder. The telemeter comprises a movable reflecting prism A operated through the lever A<1> by the objective focusing mechanism. The other reflecting surface B is formed by cementing two glass plates G, G<1> together, with semi-transparent silvering extending over a small central rectangular portion of the dividing surface. The two parts G, G<1> may, instead of being cemented together, be separated by a small air gap. The view finder comprises a spherically curved glass plate E<1> having a rectangular silvered portion E surrounding a transparent area E<2> and reproducing substantially at infinity an opaque rectangular mark C<2> on a glass plate C, the central portion C<1> of which constitutes the viewing opening. The mark C<2> is illuminated by windows H<1>. The casing H or a combined casing for the telemeter and view-finder, may be detachable from the camera. The plate C may bear a number of rectangular marks C<2> corresponding to different camera objectives. In a modification, the concave reflector may be located across the telemeter base, and the view -finder provided with an eyepiece and objective.