Autofocus with adapted lenses: what actually works
Which adapters keep autofocus, which only manage single-shot AF, and why screw-drive lenses stop focusing. A tier-by-tier guide to adapted-lens AF.
Autofocus through an adapter works best when one company made the lens, the adapter and the camera: Canon’s EF-EOS R and Nikon’s FTZ pass autofocus through much as a native body would. Third-party “smart” adapters that translate one maker’s lens protocol into another’s usually manage reliable single-shot AF, but continuous tracking and eye detection vary lens by lens. Older lenses that rely on a focus motor in the camera body often will not autofocus at all.
That is the short version. The detail decides whether a particular lens is worth adapting, so it is worth taking in tiers.
The three tiers
| Tier | Examples | What to expect |
|---|---|---|
| Same maker, same protocol | Canon EF-EOS R, Nikon FTZ / FTZ II, Sony LA-EA5, Olympus MMF-3 | Near-native AF, with specific documented exceptions |
| Translating adapter | Sigma MC-11 and MC-21, Metabones Smart Adapter, Megadap ETZ21, Techart TZE, Fringer EF-NZ | Good single-shot AF; tracking and eye AF depend on the lens |
| No electronics | Any plain ring for M42, Canon FD, Leica M | Manual focus only |
The mechanical tier is simple and covered in using vintage manual lenses on mirrorless. The rest of this post deals with the first two.
Tier one: the maker’s own adapter
When a manufacturer moves from an SLR mount to a mirrorless one, it usually sells an adapter that speaks both languages natively. The camera is not being fooled into anything; it was designed to accept those lenses.
Canon EF to RF. The EF-to-RF pairing is the best-behaved adaptation there is. Canon’s adapter passes autofocus, image stabilisation, aperture control and EXIF data through, and Canon lists EF, EF-S, TS-E and MP-E lenses as compatible. EF-S lenses work too, with the body switching to crop mode automatically.
Nikon F to Z. Nikon says the FTZ II supports around 360 F-mount Nikkor lens types, but autofocus only works with the 94 types that have a motor inside the lens: AF-S, AF-P and AF-I. Everything else, including the older AF and AF-D lenses, mounts and meters but focuses by hand. See Nikon F lenses on Nikon Z for the full picture.
Sony A to E. Sony’s LA-EA5 is the unusual one: it contains its own focus motor, so it can drive old Minolta and Sony screw-drive lenses. How much of that works depends on the camera body, and Sony lists every E-mount body as “compatible, but with restrictions”, so check its compatibility chart for your camera. More on the Sony A lenses on Sony E page.
Four Thirds to Micro Four Thirds. Olympus’s MMF-3 and Panasonic’s DMW-MA1 connect electronically, but Four Thirds lenses were built for phase-detection AF. On bodies with on-sensor phase detection they focus properly; elsewhere they hunt. See Four Thirds on Micro Four Thirds.
Tier two: adapters that translate
A translating adapter sits between two systems that were never meant to meet. It has a chip that receives the camera’s autofocus commands in one protocol and reissues them to the lens in another. Canon’s EF protocol has been reverse-engineered by third parties rather than licensed to them, which is why these adapters depend on firmware and why their makers publish lens-by-lens compatibility lists instead of blanket promises.
Sigma MC-11 and MC-21
Sigma’s converters are first-party in one sense: Sigma made both the adapter and the lenses it officially supports. The MC-11 puts Sigma’s Canon EF-mount (and SA-mount) lenses on Sony E; the MC-21 does the same for L-Mount. Both are officially supported with Sigma lenses only, though the MC-11 is widely used with Canon lenses as well.
The MC-21 is the clearest example of a single-AF-only adapter. Sigma’s own product page states that only AF-S works and AF-C cannot be selected, and lists further limits on some bodies, such as no touch AF on Panasonic cameras and manual focus only during video on Leica cameras. For Canon EF lenses on L-Mount, that rules it out for moving subjects.
Metabones, Viltrox and Fringer
For Canon EF lenses on Sony E, Metabones’ Smart Adapter Mark V lists continuous AF tracking and an assignable button for Eye-AF on supported cameras. Metabones also notes that autofocus accuracy “depends heavily on the design and working condition of the lens”. In practice single-shot AF is close to native; continuous tracking and eye detection are where individual lenses fall down. Fringer’s EF-NZ does a similar job for Canon EF on Nikon Z, with performance that trails the same lens on a Canon RF body.
Mirrorless to mirrorless: Megadap and Techart
A handful of adapters put one mirrorless system’s lenses on another. Sony E’s flange distance is 18.0 mm and Nikon Z’s is 16.0 mm, and that 2 mm is enough for an electronic adapter. Techart’s TZE-01 was the first, with Techart stating AF-S, AF-C and face and eye detection all work. Megadap’s ETZ21 Pro series also advertises AF-S, AF-C and eye AF. On both, which lenses behave well has changed repeatedly with firmware, so treat any lens-level claim as dated. See Sony E lenses on Nikon Z.
Why single AF works and tracking struggles
Single-shot AF is forgiving. The camera asks the lens to move, checks focus, and stops once it is sharp; a slower or slightly imprecise exchange still ends in a sharp frame. Continuous AF and subject tracking send a constant stream of small corrections while the subject moves, and every delay in translation shows up as missed frames. Eye detection builds on tracking, so it inherits the same weakness.
That is why the useful question is rarely “does this adapter autofocus?” It is “does this adapter do continuous AF with my lens, on my body, on the current firmware?”
Firmware and compatibility lists
Translating adapters are updated like cameras:
- Sigma updates the MC-11 over USB with its SIGMA Optimization Pro software, and firmware releases have added support for newer Sigma lenses.
- Megadap’s ETZ21 Pro can be updated through the Nikon Z camera itself.
- Techart shipped the TZE-01 with a lens dock for firmware upgrades that add lens support.
Before buying, find the maker’s compatibility list, look for your exact lens (including version, since “Mark II” often behaves differently), and check the date of the list. If your lens is not on it, assume single AF at best.
Screw-drive lenses
Before lenses carried their own focus motors, many autofocus SLRs used a motor in the body that turned a screw in the lens. No mirrorless body has that motor.
- Nikon AF and AF-D lenses do not autofocus on the FTZ or FTZ II. Nikon’s own figures cover this: AF works with AF-S, AF-P and AF-I lenses only.
- Minolta and Sony A screw-drive lenses can autofocus on Sony E through the LA-EA5, which has its own motor, depending on the body.
- Third-party motors for Nikon. MonsterAdapter announced the LA-FZ1 in February 2025, an F-to-Z adapter with a built-in focus motor for AF and AF-D lenses. At launch its firmware did not support VR, electromagnetic apertures or lenses with their own motors, so it is a specialist tool rather than a replacement for the FTZ.
Manual lenses that autofocus
There is one odd category. Techart’s LM-EA9 puts Leica M lenses on Sony E and autofocuses them by moving the whole lens back and forth rather than turning its focus ring, using the camera’s phase-detection AF. It exists, but it is a different proposition from the purely mechanical adapters on the Leica M lenses on Sony E page.
Where to go next
- The compatibility matrix shows every lens-to-body pair this site covers.
- The adapter index lists each pairing with its autofocus rating.
- For why some mounts can host an electronic adapter at all, see flange focal distance explained.
- For Sigma’s MC-21 on L-Mount: Search Amazon UK.