Canon A-1 35mm SLR Film Camera with Canon 28mm f2.8 Lens

The A-1 is a 35mm SLR camera from Canon that, like its predecessor the AE-1, was innovative when released in 1978.

It was notable for its programmed automatic exposure setting, whereby both aperture and shutter speed are automated. While not labelled as such, it was a pioneer in offering the full "PASM" set of exposure options, standard in many later cameras through the present day. Canon's competitors were considerably slower in introducing programmed SLRs: Minolta in 1982 with the X-700, Nikon with the FA and Pentax with the Super A in 1983 and Olympus with the OM-2S Program in 1984.

The A-1 has the Canon FD bayonet lens mount and was normally sold with the Canon FD 50mm f/1.8 or 50mm f/1.4 lens. The A-1 accepts any lens with the Canon FD (1971) or FDn (1979) bayonet mount. The more recent EF mount autofocus lenses (1987) cannot be fitted, nor can the FD mount lenses be fitted to autofocus Canon SLRs without an adapter.

The A-1 has the choice of aperture- or shutter-priority automatic exposure, the first[1] "programmed" fully-automatic exposure mode, as well as automatic dedicated flash, and a fully manual setting. There is a numerical display in the viewfinder of shutter and aperture, using red LED seven-segment displays. To avoid fogging from the viewfinder on long exposures, the LED display can be switched off, and the eyepiece closed off with a shutter.

The settings dial is shown (right) set to shutter-priority auto ("Tv"). The programmed setting (marked [P] in a green square) is just past the 1/1000 mark. Rotating the collar around the shutter-release to "Av" sets aperture-priority and changes the scale from speed (black background) to aperture settings (on a yellow background). Speeds (manual or auto), or apertures (in auto mode) are adjusted by a wheel in front of the dial; the photographer's right index finger naturally falls on this. There is a sliding cover for the wheel, preventing accidental changes to settings. The A-1 does not have a mirror lock.