EXPOSURE CONTROL DEVICE FOR STROBOSCOPIC PHOTOGRAPHING

摘要

PURPOSE:To prevent the titled device from the generation of a miss due to day photographing using a stroboscope as auxiliary light by delaying the output time of a close control signal based on exposure data when the aperture of a lens is so small as to photograph at the emitting of the stroboscope. CONSTITUTION:When the maximum aperture of the lens is Fm and the aperture of the lens is Fs, the step difference Fs-Fm of the lens aperture which is calculated by a step difference arithmetic circuit 13a based on exposure data and opening data is inputted to a correcting value determining circuit 13b and converted into a time signal proportional to the stop difference Fs-Fm and the time signal is inputted to the 1st time constant circuit 4. The circuit 4 delays an output time T3 of an aperture close control signal determined by exposure data obtained from an exposure arithmetic circuit 2 by a correction value DELTAT determined by the step difference Fs-Fm. A sector is transferred to a closing process at a time T4 delayed from the time T3 determined from the guide number of the stroboscope found out by an aperture value arithmetic circuit 7 only by a correcting value DELTAT. Consequently, the aperture of a shutter is increased and the aperture appropriate for stroboscopic photographing is formed to obtain exposure proper to a main object.