Viewing system for reflex camera
AssigneeOptigon Research & Development Corporation
InventorsRichard M. Altman, Thomas D. McLaughlin
Life of this patent
Estimating the term…
Abstract
A viewfinder system for a single lens reflex camera where the field lens of the system is positionable in accordance with the distance of the objective lens exit pupil from the focal plane and eyepiece lenses are positionable in accordance with the field lens to maintain uniform viewfinder brightness without any essential change in image magnification.
Claims20
In a viewing system for a single lens reflex camera having a focal plane comprising a viewing screen, a field lens, a prism and an eyepiece, said camera having the ability to accept lenses having exit pupils of varying location with respect to the focal plane of said camera, the improvement comprising a movable field lens between said screen and said prism, and means for positioning said movable field lens between said prism and said screen as a function of the location of the exit pupil of a lens mounted to said camera.
In a single lens reflex camera having a demountable objective lens, a pivotal mirror behind the objective lens in front of the focal plane arranged to reflect an image to a viewing system comprising a focusing screen, a field lens, a prism having entrance and exit windows with reflecting surfaces therebetween, and an eyepiece lens in that order, the improvement comprising said field lens being movable between said screen and said entrance window, said eyepiece being positionable with respect to said exit window as a function of the position of said field lens and means for positioning said field lens between said screen and said entrance window as a function of the location of the exit pupil of said lens with respect to the focal plane.
Dependencies are inferred from the claim text.