Abstract: An arrangement for controlling the flash duration in photographic cameras. A light-sensitive element within the apparatus responds to light originating from the source for flash bulbs and reflected by the object or scene to be photographed. The flash bulb is ignited by an ignition circuit which also generates the operating voltage for the light-sensitive device. Through the application of a discharge tube which has a considerably lower internal resistance, when ignited, than the flash bulb, the latter becomes extinguished when the .Iadd.quantity of .Iaddend.light reflected by the object or scene and impinging upon the light-sensitive device, is .[.of.]. a predetermined .[.magnitude.]. .Iadd.quantity..Iaddend.