# Canon R/FL/FD — Camera mount flange focal distance and adapter feasibility

For Canon R/FL/FD, flange focal distance (mm) is 42; mount type is breech or bayonet; throat diameter (mm) is 48, verified against its source on 2026-08-13.

- **Mount name:** Canon R/FL/FD _(verified: appears in the quote below)_
- **Flange focal distance (mm):** 42 _(verified: appears in the quote below)_
- **Mount type:** breech or bayonet _(verified: appears in the quote below)_
- **Throat diameter (mm):** 48 _(verified: appears in the quote below)_

## What the source says

> Canon R/FL/FD | breech or bayonet | 42 | 48 |

## Source

- https://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html

Last verified: 2026-08-13. Review by: 2028-08-12.
Part of [Camera mount flange focal distance and adapter feasibility](https://referencesource.org/camera-lens-body-adapter-compatibility/).