To expose optical data on photographic film with sufficient exposure.

A PAR(print aspect ratio) mark exposure circuit 50 to expose a PAR mark for discriminating a print mode is incorporated in a stroboscopic circuit. When a shutter mechanism is actuated and a trigger switch 29 is turned on, a timer circuit 60 is actuated only for a specified time so as to turn on a transistor for latching 24. Thus, an oscillation transistor 22 and an oscillation transformer 23 are started to be actuated and a main capacitor 26 is charged to specified charge voltage. Meanwhile, a transistor for an LED 51 is turned on only for the specified time by the timer circuit 60, and a light emitting diode 14 being a light source to expose the PAR mark emits the light at pulse voltage obtained when counter elecromotive force is generated in the transformer 23 which is actuated. Since the counter electromotive force is repeatedly generated for the specified fine, the diode 14 emits the light repeatedly.