Metabones · Canon EF → Sony E adapter
Metabones Speed Booster ULTRA 0.71× EF-E — Canon EF → Sony E adapter
Focal reducer for APS-C Sony E bodies (a6xxx series) — multiplies aperture by ~1 stop and reduces focal length by 0.71×, effectively letting EF full-frame lenses cover the APS-C sensor with extra light.
At a glance
- Vendor
- Metabones
- Release year
- 2014
- Body-side contacts
- 11 pins
- Flags
- firmware-updatableweather-sealed —requires glass
What this adapter preserves
Compatibility for Canon EF lens on a Sony E body (computed from the lensmount dataset — open the Canon EF to Sony E adapter page for the full verdict, flange clearance, and adapter caveats).
- Focus: Full AF
- IS: IS / IBIS preserved
- Aperture: Electronic aperture
- Infinity focus: Reaches infinity
What it does
Not for full-frame E-mount bodies (image circle won't cover the sensor).
Same side USB port as the plain EF-E V — firmware track is shared lineage with the non-Booster Mark V.
Firmware history
Firmware history
- v0.51
- Phase-detect AF support on Sony APS-C bodies with on-sensor PDAF (a6300 / a6500)
- v0.69
- Tracking improvements on a6600 with Sigma EF Art / Contemporary lenses
Approximate milestones — verify against the Metabones firmware page for the authoritative changelog.
Try your lens through this focal reducer
Pick a lens focal length, max aperture, target body sensor format, and reducer family below — the calc returns the effective focal length, effective f-number, and full-frame equivalent angle of view on that body. Both focal length and f-number scale by the reducer ratio (so the lens always gets two stops faster, distributed as −2·log₂(ratio) stops).
Speed Booster equivalence calculator
Plug in any Canon EF lens and pick the focal-reducer family. The calc returns the effective focal length and aperture on a APS-C body of your choice, plus the full-frame equivalent angle of view after the body's crop stacks on top.
- Effective focal length
- 35.5 mm
- Effective aperture
- f/1.28
- Full-frame equiv. angle of view
- 53.3 mm
50.0 mm × 0.71 on the reducer.
0.99 stops brighter than f/1.80.
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.
Common questions
- Can I use the Speed Booster ULTRA on a full-frame Sony body?
- No — the focal reducer concentrates the EF image circle to APS-C size, so a full-frame E body shows heavy vignetting or black corners. Use the plain Metabones EF-E V on full-frame bodies.
- How much do I gain in focal length and aperture?
- Focal length × 0.71 (an EF 50 mm acts like ~35 mm on APS-C, close to its native full-frame field of view) and ~1 stop brighter (an f/2.8 zoom behaves like ~f/2.0 effective).
- Does the Speed Booster preserve AF and electronic aperture?
- Yes — the electronics are the same as the plain EF-E V with an added optical group. Firmware shares the EF-E V's lineage and updates push through the same side-mount USB port.
Head-to-head comparisons
Mounts on either side
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More from Metabones
Same lens-side mount (Canon EF)
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- Sigma MC-11 — onto Sony E · 2016
- Sigma MC-21 — onto L-Mount · 2019
- Metabones EF-E Mark V — onto Sony E · 2017
- Viltrox EF-EOS R5 (autofocus EF-to-RF) — onto Canon RF · 2024
- Viltrox EF-NEX IV (EF-E) — onto Sony E · 2018
- Fringer EF-FX Pro II — onto Fujifilm X · 2020
- Fringer EF-GFX Pro — onto Fujifilm GFX · 2019
- Canon EF-EOS M — onto Canon EF-M · 2012
- Fotodiox Pro EF-NEX — onto Sony E · 2018
- Kipon Baveyes EF-FE 0.7x — onto Sony E · 2017
- Kipon Baveyes EF-FX 0.7x — onto Fujifilm X · 2017
- Commlite CM-EF-NEX HS — onto Sony E · 2018
- Commlite CM-EF-EOS R — onto Canon RF · 2019
- Viltrox EF-M2 II — onto Micro Four Thirds · 2018
- Fotodiox Vizelex ND Throttle EF-NEX — onto Sony E · 2014
- Fringer EF-NZ II — onto Nikon Z · 2023
Same body-side mount (Sony E)
- Sony LA-EA5 — from Sony A · 2020
- Sigma MC-11 — from Canon EF · 2016
- Metabones EF-E Mark V — from Canon EF · 2017
- Viltrox EF-NEX IV (EF-E) — from Canon EF · 2018
- Techart LM-EA9 — from Leica M · 2022
- Voigtländer VM-E Close Focus — from Leica M · 2015
- Sony LA-EA4 — from Sony A · 2014
- Sony LA-EA3 — from Sony A · 2013
- Fotodiox Pro EF-NEX — from Canon EF · 2018
- K&F Concept M42-NEX Pro — from M42 · 2018
- K&F Concept Nikon F-NEX Pro — from Nikon F · 2019
- K&F Concept Pentax K-NEX Pro — from Pentax K · 2019
- Urth M42 to Sony E — from M42 · 2019
- Urth Leica M to Sony E — from Leica M · 2020
- Kipon Baveyes EF-FE 0.7x — from Canon EF · 2017
- Novoflex SONY/OM — from Olympus OM · 2016
- 7Artisans M-FE — from Leica M · 2018
- Commlite CM-EF-NEX HS — from Canon EF · 2018
- Commlite CM-ENF-E1 Pro — from Nikon F · 2018
- Fotodiox Vizelex ND Throttle EF-NEX — from Canon EF · 2014
- K&F Concept C/Y-NEX — from Contax · 2018
- Urth Contax/Yashica to Sony E — from Contax · 2020
- K&F Concept MD-NEX — from Minolta SR · 2016
- K&F Concept PK-NEX — from Pentax K · 2016
- Fotodiox FD-NEX — from Canon FD · 2011
- Urth Olympus OM-E — from Olympus OM · 2020
Keep exploring
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