Canon FD

The Canon FD is a standard developed by Canon for mounting a photographic lens to a single-lens reflex camera (SLR) body. Introduced with the Canon F-1 camera in March 1971, the FD standard was meant to replace Canon's earlier FL mount system. The FD-mount cameras were made to be compatible with FL lenses that can operate in stop-down metering mode. This new mounting system became very popular during the 1970s and 1980s. However, the system is now obsolete and the FD cameras and mount are now available at low prices on the second-hand market. It is mostly used by 35mm film enthusiasts who seek high optical quality, but do not need autofocus capability.

The Canon FD lens mount was a breechlock mount, which ensured that the contact surface between the camera body and lens did not rotate against each other, preventing any potential scratch that could decrease the very precise lens-to-film distance. However, this mechanism meant slower changing of lenses and resulted in incorporating a bayonet-style FD mount. These new changes allowed the photographer to change lenses by twisting the lens, even though the actual mount surfaces remained fixed. This bayonet-style mount has since been adopted in Canon’s new EOS system's EF lenses. Some of the standard FD lenses comprise 24mm Canon FD lenses, 28mm Canon FD lenses and 35mm Canon FD lenses.