A still camera wherein the release element stresses a spring during a first stage of its movement from the starting position and disengages a blocking lever from a pivotable impeller during the second stage of its movement whereby the spring propels a pin of the impeller against a cartridge which fires a flash lamp or against a piezoelectric block which produces a high-voltage pulse for the firing of an electronic flash unit. At the same time, the impeller opens the shutter so that the subject or scene is illuminated by artificial light while the shutter is open. A second spring urges the release element back to its starting position. During such return movement, the release element returns the blocking lever into engagement with the impeller. The extent to which the release element moves during stressing of the spring which bears against the impeller is adjustable.