An adaptor for a camera for operating multiple flash units with a single camera device in which all of the flash units simultaneously emit light. Output signals from each of the flash units indicating that the corresponding individual flash unit is ready to emit light are coupled to corresponding inputs of a logical product circuit such as an AND gate. The single output of the AND gate is coupled to a single corresponding input of the camera device. The X contact of the camera device is coupled in common to the actuation terminals of each of the flash units.
