Canon EF (cine) — flange distance, protocol, and adapter compatibility
Cinema variant of the Canon EF mount used by Canon CN-E primes and zooms and by the C300 / C500 / C70 (in EF mode) cinema bodies. Mechanically and electronically identical to stills EF — same 44 mm flange, same 54 mm throat, same 8-pin EF protocol — but with a reinforced stainless-steel collar, 0.8 MOD cine-gear-cut focus and iris rings, geared follow-focus throws of 300°+, and parfocal zoom design. CN-E primes carry the EF electronic aperture but no AF motor; AF is by design absent because cine workflows pull focus manually via follow-focus or wireless FIZ.
Mount specifications
Flange focal distance
44 mm
Throat diameter
54 mm
Electronic protocol
Canon EF
Supported formats
full-frame, APS-H, APS-C
Manufacturer
Canon
Introduced
2011
Status
Active production
Canon EF (cine) on the flange-distance axis
Canon EF (cine) sits at 44 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.
Canon EF-EOS R (plain) — works for any EF-cine prime or zoom
Canon EF-EOS R 0.71× Cinema Speed Booster (Super 35-to-full-frame relay, designed for Canon EF-cine on C70's S35 sensor — note: the C70 itself is S35, but full-frame R5/R5 C also accept this adapter on the EF-cine glass)
Mechanically identical to mounting any EF lens on an RF body — the 24 mm EF-EOS R adapter preserves electronic aperture and is fully transparent.
AF stays manual-only because the cine lens has no AF motor; iris control is body-driven via the EF pins.
The Fringer EF-NZ II carries the EF 8-pin protocol, so it drives a CN-E cinema prime's electronic iris — set or ramp T-stops from the Z body or an external motor exactly as with a stills EF lens.
No autofocus: a CN-E prime has no AF motor (cinema glass is manual-focus by design), so focus is pulled by hand via a follow-focus or wireless FIZ.
Viltrox EF-M2 II (0.71× focal reducer, electronic)
Smart EF-MFT adapters carry the EF 8-pin protocol and pass a CN-E prime's electronic iris; the Metabones EF-MFT Speed Booster XL and Viltrox EF-M2 II are focal reducers that also widen the field of view back toward Super35 and add roughly a stop.
On a straight (non-reducing) adapter the 2× crop turns a CN-E 50 into a ~100 mm-equivalent and a CN-E 85 into ~170 mm — a tele-leaning kit; the focal reducer is what restores wider framing.
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 EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Canon EF-S (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
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.
Speed Booster equivalence calculator
Plug in any Canon EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Nikon F (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -0.5 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.
Speed Booster equivalence calculator
Plug in any Canon EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Sony A / Minolta A (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -1.5 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.
Speed Booster equivalence calculator
Plug in any Canon EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a M42 (Pentax / Praktica screw mount) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -1.5 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.
Speed Booster equivalence calculator
Plug in any Canon EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Pentax K (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -8.0 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 EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a PL (Positive Lock) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -0.7 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 EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Exakta (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -11.0 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 EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a T-mount (T2) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -0.4 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 EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Praktica B (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only 0.5 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.
Speed Booster equivalence calculator
Plug in any Canon EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Minolta SR / MC / MD (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -2.0 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 EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Olympus OM (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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.
Flange clearance is only -1.5 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.
Speed Booster equivalence calculator
Plug in any Canon EF (cine) lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a Contax/Yashica (C/Y) (APS-C), plus the full-frame equivalent angle of view after the body's crop stacks on top.
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 EF (cine) body
You own a Canon EF (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).
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.
Flange clearance is only -2.0 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.
Flange clearance is only 0.5 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.
Flange clearance is only 1.5 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.
Flange clearance is only 1.5 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.
Flange clearance is only 0.7 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.
Flange clearance is only 0.4 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.
Flange clearance is only -3.5 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.
Flange clearance is only -0.5 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.
Flange clearance is only 1.5 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.
Will Canon CN-E cinema primes work on stills EF bodies?
Yes — Canon CN-E primes (14 mm T3.1, 24 mm T1.5, 35 mm T1.5, 50 mm T1.3, 85 mm T1.3, 135 mm T2.2) mount and meter on every EF stills body (5D Mark IV, 1D X Mark III, Rebel-series). The lens has no AF motor by design, so focus is manual; aperture is electronic and operates from the body's command dial like any other EF lens. EXIF records focal length and T-stop equivalents.
Why does Canon EF (cine) have the same mount as Canon EF (stills)?
Because they are the same physical mount — 44 mm flange, 54 mm throat, 8-pin EF protocol, Canon's standard EF bayonet locking. The "cine" variant is a packaging and gearing distinction: reinforced stainless-steel collar, 0.8 MOD focus / iris / zoom rings, parfocal zoom design. The body interface is unchanged, so CN-E cine lenses interoperate freely with stills EF bodies and stills EF lenses with cine bodies.
Can EF-cine primes mount on a Canon RF cinema body like the C70?
Yes — the Canon EF-EOS R cinema-grade adapter (or the standard EF-EOS R for the C70) mounts CN-E primes onto C70 / R5 C / C400 / C300 Mark III bodies. The mechanical adapter passes the same 8-pin EF protocol that stills EF lenses use, so CN-E primes get electronic aperture control over the adapter without any cine-specific firmware path required.