Method and apparatus for transmission of information in a photographic camera

In a photographic camera having a camera body, an interchangeable lens assembly mounted on the camera body, and an automatic exposure control mechanism located in the camera body, the mechanism responding to a first binary signal representative of a maximum lens aperture value in binary code and a second binary signal representative of a minimum lens aperture value in binary code, the first signal having a given number of binary bits, a method comprising the steps of:

• generating in the lens assembly a second signal representative of the minimum aperture value for the lens assembly;
• generating in the lens assembly a third signal representative of the arithmetic difference between the first and second signals for the lens assembly, the third signal having a number of binary bits fewer than the given number;
• transmitting the second and third signals generated in the lens assembly to the camera body;
• applying the second signal to the mechanism;
• arithmetically adding the transmitted second and third signals to derive the first signal for the lens assembly;
• and
• applying the derived first signal to the mechanism.