K&F Concept · M42 → Canon RF adapter
K&F Concept M42-EOS R Pro — M42 → Canon RF adapter
Pro-line M42 screw-mount onto Canon RF — Canon's 20 mm flange (vs Canon EF's 44 mm) leaves plenty of clearance for the adapter's body, and infinity calibrates cleanly on every R-line body (R5 / R6 / R6 II / R3 / R8 / R10 / R50 / R100).
At a glance
- Vendor
- K&F Concept
- Release year
- 2020
- Body-side contacts
- None (purely mechanical)
- Flags
- firmware-updatable —weather-sealed —requires glass —
What this adapter preserves
Compatibility for M42 lens on a Canon RF body (computed from the lensmount dataset — open the M42 to Canon RF adapter page for the full verdict, flange clearance, and adapter caveats).
- Focus: Manual focus only
- IS: No IS
- Aperture: Manual aperture ring
- Infinity focus: Reaches infinity
What it does
Mechanical-only — no electronics, no AF. Aperture is controlled by the M42 lens's own ring or stop-down lever. RF body's focus magnification and peaking aids handle manual focus.
Common questions
- Is the K&F M42-EOS R Pro compatible with every Canon RF body?
- Yes — mechanical adapters only care about the body-side bayonet, and every Canon RF body shares the same mount geometry. R5 II / R5 / R6 II / R6 / R3 / R8 / R10 / R50 / R100 all accept the adapter identically. EOS R-line crop bodies (R7, R10, R50, R100) will of course apply their 1.6× APS-C crop factor automatically to the M42 lens's image circle.
- Will infinity focus work on every M42 lens?
- Yes — calibration is designed to clear infinity by a fraction. A few M42 lenses with non-standard rear-element protrusion (Carl Zeiss Jena Pancolar 50 mm f/1.8 in some manufacturing batches, certain Pentacon 135 mm units) may need verification; if a lens focuses noticeably past infinity, that's normal and expected for the adapter's tolerance.
- Does Canon's APS-C crop on R7 / R10 / R50 affect the adapter?
- No, the adapter itself is mechanically format-agnostic. On an R7 / R10 / R50 / R100 (APS-C RF bodies), the body uses the central 22.3 × 14.9 mm crop of the M42 lens's full-frame image circle — a 1.6× effective focal-length multiplier. The adapter doesn't intermediate this; the lens's image circle remains identical regardless of body sensor size.
Mounts on either side
Other adapters worth comparing
More from K&F Concept
Same lens-side mount (M42)
- K&F Concept M42-NEX Pro — onto Sony E · 2018
- Urth M42 to Sony E — onto Sony E · 2019
- Kipon Baveyes M42-MFT 0.7x — onto Micro Four Thirds · 2016
- K&F Concept M42-NZ — onto Nikon Z · 2019
Same body-side mount (Canon RF)
- Canon EF-EOS R — from Canon EF · 2018
- Viltrox EF-EOS R5 (autofocus EF-to-RF) — from Canon EF · 2024
- Novoflex EOSR/LEM — from Leica M · 2019
- Commlite CM-EF-EOS R — from Canon EF · 2019
- Fotodiox FD-RF — from Canon FD · 2019
Keep exploring
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