Abstract: An ultrasonic rangefinder system for use in either an ultrasonic rangefinder camera or a general purpose ultrasonic rangefinder designer's kit provides a plurality of automatic sonic rangefinder functions when embodied in the photographic rangefinder camera while at the same time accommodating independently established control functions overriding the automatic functions when the rangefinder is utilized as part of the general purpose sonar rangefinder designer's kit.

Abstract: A photographic exposure control system of the type for controlling both the duration of a photographic exposure interval and the amount of artificial illumination provided during the exposure interval includes the capability of increasing the amount of artificial illumination in direct corresponding relation with increases in the camera-to-subject distance and the ambient scene light intensity in order to maintain the same proportional contribution to the film exposure from the ambient artificial light during a fill flash exposure.

Abstract: A photographic exposure and flash fire control system initially measures ambient scene light and subsequently utilizes the results of that measurement to control the amount of artificial illumination provided during the exposure interval. The initial measurement of ambient scene light below a first select level provides for a maximum flash output while conversely the initial measurement of ambient scene light above a second select level greater than the first select level provides for minimum flash output. The initial measurement of ambient scene light between the aforementioned first and second levels provides for a flash output which progressively varies between the aforementioned minimum and maximum outputs in inverse corresponding relation with respect to the progressive variation of measured ambient scene light between its first and second select levels.

Abstract: A dual mode range responsive exposure and flash fire control system operates as a function of the photographic subject being located in either a near distance or a far distance range from the camera. For photographic subjects located within a near camera-to-subject distance range, a flash fire signal is normally provided during the exposure interval at the instant when the blade mechanism defines an aperture size generally corresponding to the camera-to-subject distance to ignite the flash and provide a determinate amount of illumination. For photographic subjects located within a far camera-to-subject distance range, a flash fire signal is normally provided subsequent to the shutter blades reaching a maximum aperture defining position with the flash output being subsequently quenched as a function of scene light detection and integration.