Photographic control system for varying both flash fire aperture and exposure termination in correspondence with film speed
First Claim
1. In a photographic exposure control system for use with a source of artificial illumination and for controlling the exposure of a photosensitive recording medium, the system having a shutter arrangement for at least initially providing progressively increasing aperture values at a predetermined rate during an exposure interval within which scene light is transmitted to the photosensitive medium following actuation of the shutter arrangement, and means for providing a flash fire signal to ignite the source of artificial illumination during the exposure interval at an appropriate follow focus aperture value corresponding to the subject distance, the improvement comprising selectively actuatable means for varying the follow focus aperture at which the flash fire signal is provided in correspondence with different ones of a select plurality of film speeds.
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Accused Products
Abstract
In a photographic exposure control system of the type which provides a flash fire signal at an appropriate follow focus aperture value corresponding to the camera-to-subject distance range and which terminates the exposure interval as a function of scene light detection and integration to a select level, there is provided an arrangement by which the exposure control system may be selectively adjusted to accommodate any one of a variety of different film speeds.
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Citations
9 Claims
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1. In a photographic exposure control system for use with a source of artificial illumination and for controlling the exposure of a photosensitive recording medium, the system having a shutter arrangement for at least initially providing progressively increasing aperture values at a predetermined rate during an exposure interval within which scene light is transmitted to the photosensitive medium following actuation of the shutter arrangement, and means for providing a flash fire signal to ignite the source of artificial illumination during the exposure interval at an appropriate follow focus aperture value corresponding to the subject distance, the improvement comprising selectively actuatable means for varying the follow focus aperture at which the flash fire signal is provided in correspondence with different ones of a select plurality of film speeds.
- 2. In a photographic exposure control system for use with a source of artificial illumination and for controlling the exposure of a photosensitive recording medium, the system having a shutter arrangement for at least initially providing progressively aperture values at a predetermined rate during an exposure interval within which scene light is transmitted to the photosensitive medium following actuation of the shutter arrangement, means for providing a flash fire signal to ignite the source of artificial illumination during the exposure interval, and means for determining the distance of a photographic subject from the system to define a range related time interval corresponding to the subject distance and for producing the flash fire signal responsive to a lapse of a time period commencing at the initiation of the exposure interval and corresponding to the range related time interval to thereby produce the flash fire signal at an aperture value corresponding to the subject distance, the improvement comprising selectively actuatable means for varying the lapsed time period at which the flash fire signal is provided in correspondence with different ones of a select plurality of film speeds.
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5. In a photographic exposure control system for use with a source of artificial illumination and for controlling the exposure of a photosensitive recording medium, the system having a shutter arrangement for at least initially providing progressively increasing aperture values at a predetermined rate during an exposure interval within which scene light is transmitted to the photosensitive medium following actuation of the shutter arrangement, means for detecting scene light and for responding to the detection of a select amount of scene light to terminate the exposure interval and means for providing a flash fire signal to ignite the source of artificial illumination during the exposure interval at an appropriate follow focus aperture value corresponding to the subject distance, the improvement comprising selectively actuatable means for varying both the follow focus aperture at which the flash fire signal is provided and the select amount of ambient light to be detected to terminate the exposure interval in correspondence with different ones of a select plurality of film speeds.
- 6. In a photographic exposure control system for use with a source of artificial illumination and for controlling the exposure of a photosensitive recording medium, the system having a shutter arrangement for at least initially providing progressively increasing aperture values at a predetermined rate during an exposure interval within which scene light is transmitted to the photosensitive medium following actuation of the shutter arrangement, means for detecting scene light and for responding to the detection of a select amount of scene light to terminate the exposure interval and means for determining the distance of a photographic subject from the system to define a range related time interval corresponding to the subject distance and for producing the flash fire signal responsive to a lapse of a time period commencing at the initiation of the exposure interval and corresponding to the range related time interval to thereby produce the flash fire signal at an aperture value corresponding to the subject distance, the improvement comprising selectively actuatable means for varying both the lapsed time period at which the flash fire signal is provided and the select amount of scene light to be detected to terminate the exposure interval in correspondence with different ones of a select plurality of film speeds.
Specification