Lens mount
Canon FD mount
Canon FD is a breech-lock bayonet with a 42.0mm register, introduced in 1971 and replaced by the electronic EF mount in 1987.
- Type
- breech-lock bayonet
- Flange distance
- 42 mm
- Introduced
- 1971, Canon F-1 and FTb
- Status
- Replaced by Canon EF in 1987. Last FD body, the T60, shipped in 1990.
About the Canon FD mount
Canon FD is the manual-focus SLR mount Canon used from 1971 to 1987. It has a 42.0mm flange distance and a breech-lock design: the original FD lenses (chrome nose, S.C. and S.S.C. coatings) mount by seating the lens and rotating a knurled locking ring, while the New FD lenses from 1979 rotate the whole barrel but keep the same breech-lock mechanism inside. FD superseded the FL mount of 1964 and kept backward compatibility with it, which is why FL lenses fit FD bodies but meter stopped down. S.S.C. stands for Super Spectra Coating, Canon's multi-coating from 1973.
FD's short 42.0mm register was an advantage for lens design and is the reason the mount died: when Canon moved to autofocus it chose a clean break with the 44.0mm electronic EF mount in 1987 rather than retrofit FD. The same short register makes FD glass awkward on DSLRs (no infinity without a corrective element) but ideal on mirrorless, where any adapter has more than 20mm of room. The one mechanical detail that matters is the stop-down lever: an FD adapter must include a locking ring that actuates it, or the lens stays wide open regardless of the aperture ring.
Aperture control
Automatic diaphragm driven by a stop-down lever on the rear of the lens. Off the camera, the lens sits wide open until that lever is moved.
Adapting it
The adapter needs a control ring (usually marked Open and Lock) that engages the stop-down lever. Mount the lens in the Open position, turn the ring to Lock, and the aperture ring then stops the lens down normally. FD lenses cannot reach infinity on any DSLR without corrective optics because 42mm is shorter than every DSLR register.
Canon FD lenses in the catalog
| Lens | Focal length | Aperture | Years | Used value |
|---|---|---|---|---|
| Canon FD 35mm f/2 (concave) | 35mm | f/2 | 1971-1979 | $150 to $500 |
| Canon FD 50mm f/1.4 S.S.C. | 50mm | f/1.4 | 1971-1990s | $55 to $200 |
| Canon FD 55mm f/1.2 S.S.C. | 55mm | f/1.2 | 1973-1979 | $180 to $600 |
| Canon FD 85mm f/1.8 S.S.C. | 85mm | f/1.8 | 1974-1990s | $100 to $340 |
Adapting Canon FD to a modern body
Frequently asked
Can Canon FD lenses be adapted to mirrorless cameras?
Yes. Canon FD has a 42mm register, longer than any mirrorless mount, so a plain mechanical adapter reaches infinity on Sony E, Fuji X, MFT, Canon RF, Nikon Z, and L-mount. The adapter needs a control ring (usually marked Open and Lock) that engages the stop-down lever. Mount the lens in the Open position, turn the ring to Lock, and the aperture ring then stops the lens down normally. FD lenses cannot reach infinity on any DSLR without corrective optics because 42mm is shorter than every DSLR register.
What is the flange distance of the Canon FD mount?
The Canon FD flange distance is 42mm. It is a breech-lock bayonet introduced in 1971 on the Canon F-1 and FTb. Replaced by Canon EF in 1987. Last FD body, the T60, shipped in 1990.
How much do Canon FD lenses cost used?
The 4 Canon FD lenses in the LensVault catalog range from $55 to $600 used. The least expensive is the Canon FD 50mm f/1.4 S.S.C. at a typical $100. Values are estimates from recent sold listings and dealer pricing, not appraisals.