Updated firmware - that we do not recommend you try until reading our caveats (see 'Update' section below) - allows Sony users to use all their AF modes when shooting Canon EF-mount lenses with Metabones adapters. It does so by emulating a native Sony lens, much like the recent Sigma MC-11 adapter. This update to the Metabones line of Smart Adapters and Speed Boosters enables the use of modes such as continuous Eye-AF and Direct Manual Focus. Updated firmware also brings smoother aperture control to most of Metabones' adapters, which may be compelling to videographers. And though the company doesn't make any claims as to video focusing, if the adapters do truly emulate native E-mount lenses, we'd expect AF functionality during video.

The Metabones is only the second E-mount adapter to offer 'native' lens functionality with adapted lenses, with the Sigma being the first.* However, in practice the Sigma MC-11 has had many issues, too often reverting to contrast-detect AF off-center, and constantly hunting back and forth in minute increments in AF-C.

It's not surprising, then, that Metabones lists a series of caveats and exceptions, most of which reflect the range and diversity of EF lenses that people might use. There are also warnings of increased battery usage and of poor continuous AF performance from lenses that aren't designed to be driven in the pattern required for fast contrast-detection AF. Finally, Metabones mentions potential problems when shooting stopped down, undoubtedly a result of Sony's 'stop-down focusing' that cripples the AF system if you shoot at smaller apertures by depriving the AF system of light, and literally shutting off phase-detection altogether at apertures smaller than F8.

Firmware for the latest adapters can be downloaded from the Metabones website. Owners of Mark I, II or III Smart Adapters and original Speed Boosters will need to return their adapters to the factory, where they will be updated free-of-charge.

UPDATE: We've tried out the new firmware on a Smart Adapter IV paired with a few lenses (Canon 35mm F1.4L II, 70-200 F2.8L II,  all Sigma Art primes) on a Sony a7R II. Phase-detect functionality appears to be limited to a very small central region, which means excessive hunting with off-center points, or Lock-on and Eye AF (both in AF-C) for non-central subjects. While AF in video is possible, it's slow with significant hunting. At this point, a7/R II and a6300 owners may find this update largely useless (or even counter-productive), though you can always revert to 'Green' (previous default) mode by de-attaching and re-attaching the adapter with its one function button held down. a7 Mark I and a6000 owners may benefit from the update enabling phase detection in the central area, but we found even this unreliable.

Press Release:

Metabones® Adds "Native" AF and Smooth Iris to EF Mount Speed Boosters® and Smart Adapters by Firmware Upgrade

Vancouver, Canada, June 23, 2016: Metabones® releases Metabones App 2.3, a major firmware update with the following additional features.

  • Eye-AF (A6300/A7series).
  • Fast contrast detect AF for all E-Mount cameras.
  • DMF (direct manual focus) for E-Mount cameras, where the camera switches to MF as soon as AF completes. This is useful for checking AF accuracy when used with focus peaking.
  • Smooth iris for Sony E-Mount and FZ-Mount cameras and Blackmagic, JVC and Panasonic Micro Four Thirds Mount cameras.

Metabones® has already added fast EF lens autofocus to its Micro Four Thirds Mount Speed Boosters® and Smart Adapters™ last year. With this speedy advantage now extended to E-Mount, EF-Mount lenses are now capable of focusing quickly across the widest variety of mirrorless cameras with trusted Metabones precision and reliability.

The smooth iris feature slows down the movement of the electromagnetic aperture diaphragm so that video footage transitions smoothly when the aperture changes, with reduced tick noise from the lens. The latest Canon and Tamron SP lenses have special support for this feature and Metabones® makes use of it if the lens supports it.


  • E-Mount "native" autofocus features may not work with all lenses.
  • "Native" autofocus may be lesser in performance and/or accuracy compared to the original "Green" mode phase-detect autofocus for A6300, A7 Mark II and A7R Mark II.
  • AF-C and video autofocus may have unsatisfactory AF performance and/or accuracy. This is a limitation inherent in DSLR lenses, which lack the low latency required for making many fine movements in rapid succession during AF-C and video focusing.
  • Excessive hunting may occur if a small aperture is used with AF-C, video or "Liveview Display Setting Effect" turned on.
  • The first few autofocus attempts may result in false positives where the camera gives focus confirmation but the subject is not in focus. This issue goes away on its own after a few trials with most lenses.
  • No support for in-camera correction such as peripheral shading, CA and distortion.
  • Power consumption may increase compared to the original "Green" mode autofocus. We recommend turning off the "Pre-AF" option to conserve battery power. On A7 series cameras and A6300 the option is on page 3 under the "gear" tab.
  • Actuations of the electromagnetic aperture diaphragm and/or the focus motor of the lens result in noises which may be picked up by the camera's internal microphone during video recording. Use of an appropriately placed external microphone is required for video work.
  • The aperture moves in 1/3 stop steps with most Panasonic cameras and 1/8 stop steps with other cameras, which may be noticeable in video recordings. Programmed exposure mode and shutter priority exposure mode should not be used for video. Lenses supporting "smooth iris" smooth out the transition but do not increase iris resolution.

The following lenses have been tested for "native" AF. Refer to Metabones' web site for the most up-to-date list. Lenses equipped with smooth iris support are marked with asterisks. APS-C lenses are not compatible with Speed Booster®.

  • Canon EF 8-15mm f/4L USM Fisheye*
  • Canon EF-S 17-55mm f/2.8 IS USM
  • Canon EF-S 18-55mm f/3.5-5.6 IS II*
  • Canon EF 24-105mm f/4L IS USM
  • Canon EF 28-80mm f/3.5-5.6 II
  • Canon EF 40mm f/2.8 STM*
  • Canon EF 50mm f/1.2L USM
  • Canon EF 50mm f/1.4 USM
  • Canon EF 70-200mm f/2.8L IS II USM*
  • Canon EF 70-200mm f/4L USM (non-IS)
  • Canon EF 70-300mm f/4-5.6L IS USM*
  • Canon EF 85mm f/1.2L II USM
  • Canon EF 100mm f/2.8L IS USM Macro*
  • Canon EF 100-400mm f/4.5-5.6L IS USM (I)
  • Canon EF 100-400mm f/4.5-5.6L IS II USM*
  • Canon EF 200mm f/2.8L II USM
  • Canon EF 300mm f/4L IS USM
  • Sigma 18-35mm f/1.8 DC HSM Art 013
  • Sigma 24-105mm f/4 DG OS HSM Art 013
  • Sigma 50mm f/1.4 EX DG HSM
  • Tamron SP 24-70mm f/2.8 Di VC USD A007
  • Tamron SP 45mm f/1.8 Di VC USD F013*
  • Tamron SP 70-200mm f/2.8 Di VC USD A009*

Incompatible lenses: ("Green" mode PDAF is still supported on A6300, A7 Mark II and A7R Mark II.)

  • Canon EF 50mm f/1.8 II
  • Canon EF 100mm f/2.8 USM Macro
  • Canon EF 135mm f/2L USM
  • Contax N lenses modified to EF mount by Conurus Canada
  • Sigma 18-125mm DC OS HSM
  • Tamron SP 17-50mm f/2.8 Di II VC B005
  • Tamron 28-300mm f/3.5-6.3 (IF) Macro A20

OSX and Windows versions of the firmware updater are available for download from Metabones' web site. The same download updates Speed Booster® ULTRA, Smart Adapter™ Mark IV, EF to FZ Mount Smart Adapter and all EF Mount to Micro Four Third mount products. Updates to earlier Smart Adapters™ (I, II and III) and the original Speed Booster® are by factory only and are free of charge except for shipping.

* A TechArt adapter was technically the first to offer native lens functionality, but it was so highly unreliable that we never considered it a viable option.