Automatic through lens exposure measuring camera - has manual override for selected area exposure control and fail-safe interlock for low battery

摘要

The automatic TTL exposure camera operates in the automatic mode with the exposure reading taken as an average value over the frame. When the mode is set for manual the exposure meter is set for manual override, with the light monitored over a selected part of the image, if required. This enables the user to accurately compensate for any part of the view, while still retaining some of the automatic control. The supply voltage is monitored, and if it falls below a set value then the automatic control is inhibited and the camera switched to manual control. In this mode all the camera functions are set to mechanical adjustment, i.e. shutter setting and operation.