PURPOSE: To automatically select a program diagram fitted to a photographing state out of plural program diagrams by selecting the program diagrams by using distance information in the case of a lens which can be changed and has the distance information and selecting the program diagram based on the information of other lens in the case of a lens which has no distance information.

CONSTITUTION: Whether a lens 52 is the lens having the distance information or not is confirmed by transmitting a command of requesting the information on the kind of a lens. When it is the lens having the distance information, a command of requesting the information on an object distance is transmitted to the lens 52 to read the distance information. When a microcomputer 1 reads the presence or absence of the distance information, in the case of the lens having no distance information, it reads a full open aperture value from a lens 20 and sets a value obtained by stopping one step from the full open aperture value. By controlling exposure based on the detected distance information, photographing appropriate for the position(distance) of the object is performed. then, a different exposure control system can be selected after discriminating that an interchageable lens in a type having no distance information is mounted.