Abstract: An automatic exposure system for an electronic flash camera incorporates an arrangement for measuring the reflectivity of a scene illuminated by the electronic flash prior to exposure in order to determine certain photographic scene characteristics for use in controlling a subsequent photographic exposure, an arrangement that substantially reduces the complexity and energy consumption of the electronic flash system while improving the ability of the exposure control system to accurately determine these characteristics. The arrangement includes the pre-exposure firing of the electronic flash to illuminate a scene with a pulse of light for a short, fixed period of time. A reflection of this light pulse is integrated for a portion of this fixed period of time. The final integrated value of the reflected light is a measure of subject reflectivity. This integrated value is then employed to derive the desired photographic scene characteristics.

Abstract: An exposure control system in a self-developing camera having a user trim adjustment for manually varying the exposure time of a picture over a limited range of exposure times is provided with a photocell for measuring the level of ambient light in a scene to be photographed and a memory for temporarily storing this scene light information. If after taking a picture of a particular scene the camera operator determines that the resulting photograph was either too light or too dark and chooses to take another picture of the particular scene, the trim control is manually adjusted to obtain the desired picture brightness level.