arbitrary position the selector switch sw may be connected to the power focus terminal pf and the enlarging lens l may be shifted upwards or downwards to adjust the focusing with the lens up key k3 and lens down key k4 being appropriately operated at this time the up down counter ud1 is set in accordance with the amount and direction of the shifting of the light source head h and up down counter ud2 is set in accordance with the amount and direction of the rotation of the motor m when the key k1 is depressed the latch circuit lt1 holds the output data d of the up down counter ud1 at the time of the key depression and produces the held data as the data d o the latch circuit lt2 holds the output data a of the up down counter ud2 at the time of the key depression and produces the held data as the data a o then when the light source head h is shifted the up down counter ud1 is set in accordance with the amount and direction of the shifting of the head the subtractor circuit st1 calculates the difference between the output d o of the latch circuit lt1 and the output d of the up down counter ud1 and outputs the data of u03b4d do d accordingly the data u03b4d represents the amount of shifting of the light source head h from the time when the key k1 was depressed then the light source head h is shifted by an.