An indicating system for indicating a diaphragm aperture suitable for scene brightness and set exposure factors, includes a pair of out-of-range indicating means for making an indication when the suitable diaphragm aperture is outside an available diaphragm range on either side of a full open and minimum aperture. The system further includes an interruption means for disabling indication of the diaphragm aperture when either of the pair of out-of-range indicating means is in operation or when the diaphragm aperture setting member is not set to the minimum diaphragm position. When an interchangeable lens, which is not adapted for the diaphragm aperture indication, is associated with the indicating system, the interruption means may also disable the diaphragm aperture indication.