Abstract: A camera having an automatic exposure system for providing decreasing aperture-interval values with increasing ambient light levels including an ambient light level sensor element for detecting an ambient light level equal to a predetermined high ambient light level and a control system for overriding the automatic exposure system in response to detecting of said predetermined level for providing a fixed effective aperture and fixed exposure time interval corresponding to the aperture-interval value defined by the automatic exposure system at the predetermined level whereby increased exposure is provided at light levels greater than the predetermined level to thereby provide a scene overexposure increasing with the amount of ambient light exceeding the predetermined level so as to provide acceptable exposure of a subject within that high light level scene.

Abstract: Method and apparatus for automatically controlling exposure of a photographic film by evaluating non-visible spectral scene light frequencies. Particularly for artificially lit scenes, an evaluation of predominantly infrared frequencies is preferred. In one embodiment, the IR scene lighting is evaluated under control of the shutter aperture system while in another embodiment, the strobe itself is controlled by its own photodetector responsive to IR scene light.

Abstract: Method and apparatus for automatically controlling exposure of a photographic film by evaluating selected spectral scene light frequencies during certain ambient light portions of an exposure interval and evaluating scene light frequencies exclusive of visible frequencies during other portions of the interval.

Abstract: Unwanted localized image effects in diffusion transfer photographs are minimized by partially removing portions of the two transverse cassette walls which constrain retained film units against lateral movement.