A Positive Vari-Focal View-Finder for Motion Picture Cameras

Vari-focal view-finders now in use change the field which corresponds to the field covered by the camera lens either mechanically or optically. Mechanical systems change the area of the image seen through the view-finder and therefore produce small images when used with telephoto lenses. The optical view-finders now in use are either negative systems, which do not allow the image produced by them to be framed properly, or they also change the area of the image. — The new view-finder consists of a vario-focal system with movable lenses producing real images corresponding to the different fields of the motion picture lenses at infinity, which are viewed through a stationary erector system. They therefore can be framed and the frame being inside the erector system always appears the same size regardless of the focal length of the view-finder.

Print ISSN

0097-5834

Published

1945-12

Content type

Original Research

DOI

10.5594/J11877