K&F Concept · M42 → Sony E adapter
K&F Concept M42-NEX Pro — M42 → Sony E adapter
Pro-line M42 (42 mm × 1 mm screw) onto Sony E with a copper-inset bayonet for tighter mechanical fit and an anti-reflective matte-black interior to suppress flare from bright legacy elements.
At a glance
- Vendor
- K&F Concept
- Release year
- 2018
- Body-side contacts
- None (purely mechanical)
- Flags
- firmware-updatable —weather-sealed —requires glass —
What this adapter preserves
Compatibility for M42 lens on a Sony E body (computed from the lensmount dataset — open the M42 to Sony E 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, no aperture coupling. M42 aperture is set on the lens's own ring (or via its stop-down lever, depending on the lens). Infinity-focus calibrated; works with Carl Zeiss Jena Pancolar / Flektogon, Pentacon, Helios-44, Super-Takumar, Industar, Mir, and every other M42 screw-mount lens shipped between 1949 and the early 1980s.
Common questions
- Will the K&F M42-NEX Pro preserve infinity focus on every M42 lens?
- Yes — the adapter is calibrated so that an M42 lens reaches mechanical infinity at its lens-side infinity mark. A handful of M42 lenses with non-standard back-flange specs (a few East German Carl Zeiss Jena Pentacon-prefix lenses, some Russian-made Helios variants) can focus slightly past infinity — that's expected and is preferable to falling short of infinity.
- What's the difference between this and the cheaper non-Pro K&F M42-NEX?
- The Pro version's copper-inset bayonet (Sony E side) reduces rotational play on the mounted lens and resists flange wear better over thousands of remounts. The non-Pro is aluminum throughout and skips the anti-reflective matte-black inner coating that suppresses flare from bright-element vintage lenses. Functionally identical for infinity focus; the Pro is ~50% more expensive and lasts noticeably longer.
- Does it have a built-in aperture-control ring for preset M42 lenses?
- No — the M42 adapter is purely a screw-to-bayonet converter. Most preset / auto M42 lenses (Pentacon Auto, Helios-44, Super-Takumar) handle their own stop-down via the lens's preset ring or stop-down lever; nothing on the adapter needs to intermediate aperture.
Mounts on either side
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Same body-side mount (Sony E)
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- Techart LM-EA9 — from Leica M · 2022
- Voigtländer VM-E Close Focus — from Leica M · 2015
- Sony LA-EA4 — from Sony A · 2014
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- Fotodiox Pro EF-NEX — from Canon EF · 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
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- K&F Concept C/Y-NEX — from Contax · 2018
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Keep exploring
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