Fujifilm · Mirrorless mount

Fujifilm X — flange distance, protocol, and adapter compatibility

Fujifilm's APS-C mirrorless mount. Shallow 17.7 mm flange makes it one of the easiest targets for legacy-lens adaptation; mechanical adapters exist for almost every SLR and rangefinder mount. AF-preserving adapters from Canon EF (Fringer EF-FX) cover much of the EF lineup.

Mount specifications

Flange focal distance: 17.7 mm
Throat diameter: 44 mm
Electronic protocol: Fujifilm X
Supported formats: APS-C
Manufacturer: Fujifilm
Introduced: 2012
Status: Active production

Adapting Fujifilm X lenses onto other bodies

You own Fujifilm X glass and want to mount it on a body with a different lens mount. Rows are sorted by feasibility.

Body mount	Result	Adapter examples	Caveats
Canon RF flange 20 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only -2.3 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Canon EF-M flange 18 mm	Speed booster MFIS lens-onlyAp. wheel	Speed Booster / focal-reducer family	Flange clearance is only -0.3 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Nikon Z flange 16 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only 1.7 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Sony E (incl. FE) flange 18 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only -0.3 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Fujifilm GFX (G-mount) flange 26.7 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only -9.0 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Micro Four Thirds flange 19.25 mm	Speed booster MFIS lens-onlyAp. wheel1.33× crop	Speed Booster / focal-reducer family	Flange clearance is only -1.6 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
L-Mount flange 20 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only -2.3 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Leica M flange 27.8 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only -10.1 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.

Adapting other lenses onto a Fujifilm X body

You own a Fujifilm X body and want to mount glass from other systems. Mirrorless-lens-onto-DSLR-body combinations are omitted (rear element collides with the mirror box).

Lens mount	Result	Adapter examples	Caveats
Canon EF flange 44 mm	Mechanical AF fullIS fullAp. electronic1.5× crop	Fringer EF-FX Pro II Fringer EF-FX2	Fringer covers most modern Canon EF lenses with phase-detect AF on X-Trans bodies. 1.5× crop applies (X-mount is APS-C).
Canon EF-S flange 44 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon EF-S lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Canon RF flange 20 mm	Mechanical MFIS lens-onlyAp. wheel1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon RF lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Nikon F flange 46.5 mm	Mechanical MFIS lens-onlyAp. wheel1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Nikon F lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Sony A / Minolta A flange 44.5 mm	Mechanical MFIS lens-onlyAp. wheel1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Sony A / Minolta A lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Fujifilm GFX (G-mount) flange 26.7 mm	Mechanical MFIS lens-onlyAp. wheel1.9× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Fujifilm GFX (G-mount) lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
L-Mount flange 20 mm	Mechanical MFIS lens-onlyAp. wheel1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between L-Mount lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
M42 (Pentax / Praktica screw mount) flange 45.46 mm	Mechanical MFIS lens-onlyAp. ring1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between M42 (Pentax / Praktica screw mount) lens and Fujifilm X body.
Leica M flange 27.8 mm	Mechanical ——Ap. ring1.5× crop	Voigtländer VM-X Close Focus Generic M-FX rings	Manual focus only; APS-C crop turns 50 mm M-mount into a ~75 mm equivalent.
Pentax K flange 45.46 mm	Mechanical MFIS lens-onlyAp. wheel1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Pentax K lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
PL (Positive Lock) flange 52 mm	Mechanical ——Ap. ring1.5× crop	Fotodiox Pro PL-FX Kipon PL-FX	1.5× crop on X-Trans means most full-frame PL primes give a ~Super-35-equivalent field of view — close to the original Super-35 framing those lenses were designed for.
Canon EF (cine) flange 44 mm	Mechanical MF—Ap. electronic1.5× crop	Fringer EF-FX Pro II Fringer EF-FX2	1.5× crop applies — a 50 mm EF-cine prime becomes a ~75 mm equivalent on X-Trans. Aperture pass-through works; AF is moot (cine prime has no motor).
Canon RF (cine) flange 20 mm	Mechanical MFIS lens-onlyAp. wheel1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon RF (cine) lens and Fujifilm X body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Exakta flange 44.7 mm	Mechanical MFIS lens-onlyAp. ring1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Exakta lens and Fujifilm X body.
T-mount (T2) flange 55 mm	Mechanical MFIS lens-onlyAp. ring1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between T-mount (T2) lens and Fujifilm X body.
C-mount flange 17.526 mm	Mechanical ——Ap. ringvignettes	Generic C-FX rings (Fotodiox, Kipon)	APS-C sensor (~28 mm diagonal) is more than 2× the C-mount image circle — heavy vignetting on every lens. Image is usable only with a heavy central crop. C-mount flange 17.526 mm vs X-mount 17.7 mm — clearance is fractional and most lenses cannot reach infinity focus on X-mount.
Praktica B flange 44.4 mm	Mechanical MFIS lens-onlyAp. ring1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Praktica B lens and Fujifilm X body.
Konica AR flange 40.5 mm	Mechanical MFIS lens-onlyAp. ring1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Konica AR lens and Fujifilm X body.
Minolta SR / MC / MD flange 43.5 mm	Mechanical MFIS lens-onlyAp. ring1.5× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Minolta SR / MC / MD lens and Fujifilm X body.
Canon EF-M flange 18 mm	Speed booster MFIS lens-onlyAp. wheel	Speed Booster / focal-reducer family	Flange clearance is only 0.3 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Nikon Z flange 16 mm	Speed booster MFIS lens-onlyAp. wheel1.5× crop	Speed Booster / focal-reducer family	Flange clearance is only -1.7 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Sony E (incl. FE) flange 18 mm	Speed booster MFIS lens-onlyAp. wheel1.5× crop	Speed Booster / focal-reducer family	Flange clearance is only 0.3 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.
Micro Four Thirds flange 19.25 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only 1.6 mm — a plain mechanical adapter cannot reach infinity focus; a focal reducer (Speed Booster) with optical glass is required. Speed Boosters typically widen the effective focal length (~0.71×) and add ~1 stop of light, which can be desirable on crop bodies.

Adapter SKU teardown

Curated adapter SKUs that involve the Fujifilm X mount on either side, with the operational specifics — body-side electronic contact count, firmware-update path, weather sealing, and whether optical glass is in the path.

Fringer EF-FX Pro II
released 2020
Canon EF lens → Fujifilm X body
- 9 body-side contacts
- firmware updatable
- not weather sealed
- no glass — pass-through
- Most reliable EF-on-Fuji-X adapter for phase-detect AF; manufacturer publishes a maintained per-lens compatibility list.
- Firmware updates over USB have continued for years post-release.

References

https://en.wikipedia.org/wiki/Fujifilm_X-mount

Mount specifications

Adapting Fujifilm X lenses onto other bodies

Adapting other lenses onto a Fujifilm X body

Adapter SKU teardown

Fringer EF-FX Pro II

References

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