| 摘要 |
PURPOSE:To improve the continuous lighting performance of a strobe and to prevent an out-of-focus image from being formed by adjusting the stop of a camera to the minimum aperture or controlling it to a light bit larger than the minimum value when the calculated minimum aperture with which strobe dimming is possible is smaller or larger than a specific value. CONSTITUTION:The X contact of a camera side is connected to the X terminal of a strobe circuit, a signal which indicates that lighting is possible by L and that lighting is stopped by H is applied to the S terminal, and a constant voltage VC is applied to a terminal C. Further, a xenon lamp 1 is turned on with a power switched to make a display on a light emitting diode 9, and a transistor TR 19 is put in operation at the same time. Then, a current is supplied from the terminal C through the operation of the TR and a discharge tube 27 for preliminary lighting illuminates in response to the output of a one-shot multivibrator circuit 25. Reflected light of this lighting is photodetected by a silicon phototransistor TR 35, whose output is processed by an operational amplifier 42 having an operational amplifying circuit 37, an HPF 38, and a switch 41 to output analog distance information VEF from a terminal a to the camera side. Then, this information VEF is processed on the camera side to control the stop.
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