| 摘要 |
PURPOSE:To control automatically a stroboscope that deos not cause an error in exposure due to difference in reflection factor without measuring reflection factor of a film by calculating the quantity of light emission at the time of main light emission basing on photometric data by preliminary light emission at a required time. CONSTITUTION:When the shutter button of a single lens reflex camera is operated, a preset aperture 202 is stopped down to a set value, a movable mirror 203 goes up, and the front curtain of a focal plane shutter 205 starts running by a control signal from the camera 100 side, and at the same time, a flash emission tube 209 makes preliminary light emission. Reflected light from the object due to this light emission is reflected by the face of front curtain of running shutter 205 through a photographing lens 201 and the aperture 202, and measured by a photo-electric element 207. The quantity of light emission of main light emission is calculated basing on the quantity of received light and quantity of preliminary light emission, and flash photographing is made by main light emission when the shutter 205 is fully opened. By control of the quantity of light based on photometry of reflected light of the object right before exposure, accurate automatic control of a stroboscope can be made without influenced by refrection factor of the film. |
