ABSTRACT
Automatic, autofocus cameras such as the Canon EOS 620 and 650 provide the user with a powerful, simple and flexible system capable of operating under a wide range of conditions. Their design encompasses the whole of mecha-tronics, requiring as it does the integration of sensor and drive technologies with the internal distributed processing power and the user interface. Sensors monitor not only the main functions of exposure control and focusing but also the internal operation of the camera, including checking the correct attachment of the lens and the correct closure of the camera back. The main microprocessor is responsible for the control of all automatic exposure and autofocus functions and provides sequence control for the complete camera, including the film transport motors. If the camera is operated with the shutter speed preselected by the user, then only the aperture value will be obtained from the metering system and this will be transferred to the lens microprocessor as before.
