Polaroid Corporation

Other

William A Shelton

Joseph M Canter

William R Pope

A control circuit for timing the duration of a flash of artificial illumination from an electronic flash maintains a substantially uniform amount of artificial illumination regardless of the ambient scene light intensity by detecting the ambient scene light intensity up to the instant that the flash is fired and thereafter subtracting the ambient scene light intensity so detected immediately prior to the flash being fired from the ambient and artificial scene light intensity detected during the flash of artificial illumination.

Control circuit for electronic flash

Photographic apparatus, e.g., a camera, having a synchronized flash. The camera includes a ranging system, an objective lens assembly movable between first and second positions for focusing an object at the camera's focal plane, a source of artificial illumination for illuminating the object, and a flash fire control in the form of an electronic flash initiation timer. The flash fire control receives an input from the ranging system which is representative of the camera-to-subject distance, and an input from the objective lens assembly upon its release for movement toward the second position. The flash fire control correlates these inputs so as to fire the source of artificial illumination while the lens assembly is still moving toward the second position and the object is in focus. In one embodiment, the intensity and/or the duration of the light from the artificial source of illumination is changed as a function of an exposure parameter, e.g., camera-to-subject distance.

Photographic apparatus having synchronized flash

Contact lenses, particularly for aphakic eyes, are characterized by a rear conicoid optical surface that is fitted to the cornea and a front prolate ellipsoidal optical surface of particular power, these surfaces having functionally related configurations.

Contact lens with reduced spherical aberration for aphakic eyes

A photographic camera apparatus is provided with an automatic illumination and exposure control system for controlling a pair of scanning type shutter blade elements as well as a flash fire and quench signal directed to a quench strobe operatively associated therewith. The camera apparatus may be operated in either a 'fill-in' flash mode of operation or an ordinary flash mode. During the 'fill-in' flash mode of operation, the time delay in quenching the strobe is progressively decreased as a function of increasing ambient scene light intensity so that the shutter blade elements admit progressively less reflected strobe light from the subject during the finite time required for the shutter blade elements to close.

Growing community of inventors

Cambridge, MA, United States of America

William A Shelton