What's the difference between Canon RF (stills) and RF (cine) mount?

None at the body-to-lens interface — same 20 mm flange, 54 mm throat, 12-pin RF protocol. "RF cine" refers to the cine-grade lenses Canon ships in RF mount (the CN-R prime line introduced in 2024: 20 mm T1.5, 24 mm T1.5, 35 mm T1.5, 50 mm T1.3, 85 mm T1.3, 135 mm T2.2). The mount itself is identical; cine-grade lenses ship with 0.8 MOD geared focus / iris / zoom rings and parfocal zoom design.

Will EF cinema primes mount on a Canon RF cinema body?

Yes — the Canon EF-EOS R adapter mounts every CN-E prime onto C70 / R5 C / C400 / R5 C cinema bodies with electronic aperture preserved (CN-E primes are manual-focus by design). The adapter is the same one used for stills EF lenses; cine-grade EF and stills-grade EF are mechanically and electronically identical at the body interface.

Does Canon's RF Speed Booster for cinema exist?

Yes — the Canon EF-EOS R 0.71× speed-booster adapter mounts EF lenses onto the Canon C70 (S35-sensor cinema body) with a 1-stop light gain and field-of-view roughly matching the equivalent full-frame view. It works only on the C70 because the S35 sensor is sized to receive the reduced 0.71× output. Stills RF bodies (R5, R6) reject the adapter because of sensor-size mismatch.

Canon · Cinema mount

Canon RF (cine) — flange distance, protocol, and adapter compatibility

Cinema variant of the Canon RF mount introduced with the EOS C70 in 2020 and adopted by the C400 / R5 C and the RF-mount CN-R prime line. Mechanically and electronically identical to stills RF — same 20 mm flange, same 54 mm throat, same 12-pin RF protocol — but with cine-grade gearing (0.8 MOD focus / iris / zoom rings), reinforced collar, parfocal zoom design, and manual-focus-first ergonomics. RF-cine glass mounts natively on every RF body (stills R5 / R6, cinema C70 / C400 / R5 C) and accepts the same EF-EOS R adapter family for legacy EF cine glass.

Mount specifications

Flange focal distance: 20 mm
Throat diameter: 54 mm
Electronic protocol: Canon RF
Supported formats: full-frame, APS-C
Manufacturer: Canon
Introduced: 2020
Status: Active production

Canon RF (cine) on the flange-distance axis

Canon RF (cine) sits at 20 mm — highlighted in orange below. The flange-distance gap between the mirrorless and SLR clusters is the room a mechanical adapter occupies; that gap is why almost every SLR lens adapts onto every mirrorless body, and why the reverse is mechanically impossible.

Flange focal distance (mm)SLR / DSLRMirrorlessRangefinderMedium-format mirrorlessCinemaLegacy SLR

Adapting Canon RF (cine) lenses onto other bodies

You own Canon RF (cine) 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
Body mount Canon RF flange 20 mm	Native MFno ISAp. electronic	no adapter required — RF-cine glass mounts natively on every RF body	RF-cine lenses are mechanically and electronically stills RF with a cine-geared barrel — they mount native on R5, R6, R3, C70, C400, R5 C, etc. Canon CN-R primes carry electronic aperture but no AF motor; iris is body-controlled, focus is fully manual via 0.8 MOD geared ring.
Body mount Canon EF-M flange 18 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 Canon EF-M body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Body mount Nikon Z flange 16 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon RF (cine) lens and Nikon Z body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Body mount Sony E (incl. FE) flange 18 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon RF (cine) lens and Sony E (incl. FE) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Body mount Fujifilm X flange 17.7 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.
Body mount C-mount flange 17.526 mm	Mechanical MFIS lens-onlyAp. wheel2.7× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon RF (cine) lens and C-mount body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Body mount Fujifilm GFX (G-mount) flange 26.7 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only -6.7 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.	Speed Booster equivalence calculator Plug in any Canon RF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Fujifilm GFX (G-mount) (medium-format), plus the full-frame equivalent angle of view after the body's crop stacks on top. Lens focal length (mm)Max aperture (f/N)Focal-reducer family Effective focal length 35.5 mm 50.0 mm × 0.71 on the reducer. Effective aperture f/1.28 0.99 stops brighter than f/1.80. Full-frame equiv. angle of view 28.0 mm 35.5 mm × 0.79× (medium-format sensor crop). A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = `−2 · log₂(ratio)`). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Body mount Micro Four Thirds flange 19.25 mm	Speed booster MFIS lens-onlyAp. wheel2× crop	Speed Booster / focal-reducer family	Flange clearance is only 0.8 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.	Speed Booster equivalence calculator Plug in any Canon RF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Micro Four Thirds (MFT), plus the full-frame equivalent angle of view after the body's crop stacks on top. Lens focal length (mm)Max aperture (f/N)Focal-reducer family Effective focal length 35.5 mm 50.0 mm × 0.71 on the reducer. Effective aperture f/1.28 0.99 stops brighter than f/1.80. Full-frame equiv. angle of view 71.0 mm 35.5 mm × 2× (MFT sensor crop). A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = `−2 · log₂(ratio)`). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Body mount L-Mount flange 20 mm	Speed booster MFIS lens-onlyAp. wheel	Speed Booster / focal-reducer family	Flange clearance is only 0.0 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.	Speed Booster equivalence calculator Plug in any Canon RF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a L-Mount (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top. Lens focal length (mm)Max aperture (f/N)Focal-reducer family Effective focal length 35.5 mm 50.0 mm × 0.71 on the reducer. Effective aperture f/1.28 0.99 stops brighter than f/1.80. Full-frame equiv. angle of view 53.3 mm 35.5 mm × 1.5× (APS-C sensor crop). A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = `−2 · log₂(ratio)`). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.
Body mount Leica M flange 27.8 mm	Speed booster MFIS lens-onlyAp. wheel	Speed Booster / focal-reducer family	Flange clearance is only -7.8 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.	Speed Booster equivalence calculator Plug in any Canon RF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Leica M (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top. Lens focal length (mm)Max aperture (f/N)Focal-reducer family Effective focal length 35.5 mm 50.0 mm × 0.71 on the reducer. Effective aperture f/1.28 0.99 stops brighter than f/1.80. Full-frame equiv. angle of view 53.3 mm 35.5 mm × 1.5× (APS-C sensor crop). A focal reducer concentrates the lens's image circle, so both focal length and f-number scale by the same ratio (stops gained = `−2 · log₂(ratio)`). The body's crop factor still applies on top — the full-frame-equivalent angle-of-view multiplier is ratio × body crop. Calculator is informational; verify against the adapter vendor's per-lens compatibility chart before purchase.

Adapting other lenses onto a Canon RF (cine) body

You own a Canon RF (cine) 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
Lens mount Canon RF flange 20 mm	Native AF fullIS fullAp. electronic	no adapter required — stills RF glass mounts natively on Canon RF-mount cinema bodies (C70, C400, R5 C)	Cinema RF bodies preserve every stills-RF feature: Dual Pixel CMOS AF II, in-lens IS, electronic aperture and Control Ring. C70 and C400 use the standard RF mount; no special adapter is needed for RF-mount L-series stills lenses.
Lens mount Canon EF flange 44 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon EF lens and Canon RF (cine) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Lens mount Canon EF-S flange 44 mm	Mechanical MFIS lens-onlyAp. wheelvignettes	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon EF-S lens and Canon RF (cine) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Lens mount Canon FD flange 42 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon FD lens and Canon RF (cine) body.
Lens mount Nikon F flange 46.5 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Nikon F lens and Canon RF (cine) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Lens mount Sony A / Minolta A flange 44.5 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Sony A / Minolta A lens and Canon RF (cine) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Lens mount Fujifilm GFX (G-mount) flange 26.7 mm	Mechanical MFIS lens-onlyAp. wheel1.27× crop	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Fujifilm GFX (G-mount) lens and Canon RF (cine) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Lens mount M42 (Pentax / Praktica screw mount) flange 45.46 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between M42 (Pentax / Praktica screw mount) lens and Canon RF (cine) body.
Lens mount Leica M flange 27.8 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Leica M lens and Canon RF (cine) body.
Lens mount Pentax K flange 45.46 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Pentax K lens and Canon RF (cine) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Lens mount PL (Positive Lock) flange 52 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between PL (Positive Lock) lens and Canon RF (cine) body.
Lens mount Canon EF (cine) flange 44 mm	Mechanical MFIS lens-onlyAp. wheel	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Canon EF (cine) lens and Canon RF (cine) body. Lens has no aperture ring; choose an adapter with a built-in aperture-control wheel.
Lens mount Exakta flange 44.7 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Exakta lens and Canon RF (cine) body.
Lens mount T-mount (T2) flange 55 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between T-mount (T2) lens and Canon RF (cine) body.
Lens mount Praktica B flange 44.4 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Praktica B lens and Canon RF (cine) body.
Lens mount Konica AR flange 40.5 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Konica AR lens and Canon RF (cine) body.
Lens mount Minolta SR / MC / MD flange 43.5 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Minolta SR / MC / MD lens and Canon RF (cine) body.
Lens mount Olympus OM flange 46 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Olympus OM lens and Canon RF (cine) body.
Lens mount Contax/Yashica (C/Y) flange 45.5 mm	Mechanical MFno ISAp. ring	generic mechanical adapter ring (multiple vendors)	Mechanical adapter only — no electronic communication between Contax/Yashica (C/Y) lens and Canon RF (cine) body.
Lens mount C-mount flange 17.526 mm	Speed booster MFIS lens-onlyAp. wheelvignettes	Speed Booster / focal-reducer family	Flange clearance is only -2.5 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.

References

Common questions

What's the difference between Canon RF (stills) and RF (cine) mount?: None at the body-to-lens interface — same 20 mm flange, 54 mm throat, 12-pin RF protocol. "RF cine" refers to the cine-grade lenses Canon ships in RF mount (the CN-R prime line introduced in 2024: 20 mm T1.5, 24 mm T1.5, 35 mm T1.5, 50 mm T1.3, 85 mm T1.3, 135 mm T2.2). The mount itself is identical; cine-grade lenses ship with 0.8 MOD geared focus / iris / zoom rings and parfocal zoom design.
Will EF cinema primes mount on a Canon RF cinema body?: Yes — the Canon EF-EOS R adapter mounts every CN-E prime onto C70 / R5 C / C400 / R5 C cinema bodies with electronic aperture preserved (CN-E primes are manual-focus by design). The adapter is the same one used for stills EF lenses; cine-grade EF and stills-grade EF are mechanically and electronically identical at the body interface.
Does Canon's RF Speed Booster for cinema exist?: Yes — the Canon EF-EOS R 0.71× speed-booster adapter mounts EF lenses onto the Canon C70 (S35-sensor cinema body) with a 1-stop light gain and field-of-view roughly matching the equivalent full-frame view. It works only on the C70 because the S35 sensor is sized to receive the reduced 0.71× output. Stills RF bodies (R5, R6) reject the adapter because of sensor-size mismatch.