Abstract: Aperture correction for a moving aperture shutter comprising a first aperture, a second larger aperture, and a mechanism for causing relative movement between the first and second apertures between an initial position where the first and second apertures are out of registry, through an intermediate position where the first aperture is partially within the second aperture and an exposure position where the first aperture is within the second aperture, and wherein the aperture correction is provided by altering a physical relationship between the first and second apertures so as to minimize the amount of exposure of the second aperture during movement through the intermediate position. The shape and/or size of the second aperture can be altered, the location of the first aperture within the second aperture in the exposure position can be altered, or there can be a combined alteration of aperture shape, size and location.

Abstract: In a photographic camera having a built-in electronic flash, a flash charging indicator, such as an LED, is illuminated whenever the flash capacitor is being charged. If the capacitor is charged for a relatively long time, e.g. 30 seconds, the photographer is alerted by the illuminated indicator of a weak battery condition. According to the invention, the flash charging indicator is additionally used to indicate that the battery source voltage is too low to adequately power a particular camera operation, such as autofocusing. This indication of a weak battery condition is provided at least as long as the particular camera operation is attempted, and it is not dependent on the flash capacitor being charged as in the prior art.

Abstract: An artificial illumination control system for controlling the energization of an electronic flash device during a photographic exposure interval in a camera has three flash related modes of operation, full flash, no flash, and fill flash, one of which is automatically selected in accordance with the level of ambient light intensity each time the exposure interval is commenced.

Abstract: An artificial illumination control system for controlling the energization of an electronic flash device during a photographic exposure interval in a camera has three flash related modes of operation, full flash, no flash, and fill flash, one of which is automatically selected in accordance with the level of ambient light intensity. If, however, the level of ambient light intensity warrants the fill flash mode, but the camera-to-subject distance exceeds a predetermined distance beyond which the flash output may be ineffectual for a fill flash exposure, the fill flash mode is prevented and the control system reverts to its no flash mode.