# Leica M — Camera mount flange focal distance and adapter feasibility

For Leica M, flange focal distance (mm) is 27.95; mount type is bayonet; throat diameter (mm) is 44, verified against its source on 2026-08-13.

- **Mount name:** Leica M _(verified: appears in the quote below)_
- **Flange focal distance (mm):** 27.95 _(verified: appears in the quote below)_
- **Mount type:** bayonet _(verified: appears in the quote below)_
- **Throat diameter (mm):** 44 _(verified: appears in the quote below)_

## What the source says

> Leica M | bayonet | 27.95 | 44 |

## Sources disagree

More than one authority states this, and they do not state the same
thing. Both are reproduced with the source each came from.

### Flange focal distance (mm)

graphics.cornell.edu says flange focal distance (mm) is **27.95**, as of 2026-08-13.

> Leica M | bayonet | 27.95 | 44 |

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

allphotolenses.com says flange focal distance (mm) is **27.8**, as of 2026-08-13.

> Leica M | 27.8 | Rangefinder 35mm camera

Source: https://allphotolenses.com/articles/item/c_6.html


### Mount type

graphics.cornell.edu says mount type is **bayonet**, as of 2026-08-13.

> Leica M | bayonet | 27.95 | 44 |

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

allphotolenses.com says mount type is **Rangefinder 35mm camera**, as of 2026-08-13.

> Leica M | 27.8 | Rangefinder 35mm camera

Source: https://allphotolenses.com/articles/item/c_6.html


## Source

- https://www.graphics.cornell.edu/~westin/misc/mounts-by-register.html
- https://allphotolenses.com/articles/item/c_6.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/).