In 1979, Canon began production of the AV-1, an aperture-priority 35mm SLR with a focal plane shutter and TTL metering. It has center-weighted averaging light metering with a back-light compensation possibility. When shooting your subject under backlighting condition, you just push an extra switch to compensate the exposure +1.5 stops. It does not have a manual exposure mode except for a single 1/60s manual shutter speed selection for flash synchronization. It takes the full range of Canon manual focus FD lenses. A dedicated film winder that advances the film at 2 frames per second can be attached to the bottom of the camera.