Two months ago Sony released a significant firmware update for its a7 III (Mac | Windows) and a7R III (Mac | Windows) cameras that brings new features, updated support and improved performance to the full-frame mirrorless cameras. We've now had a chance to thoroughly test it.

The big deal here is that firmware 2.0 unlocks all autofocus modes for adapted lenses adapted with the Sony LA-EA3 mount adapter. This includes the subject-tracking Lock-on AF modes on the a7 III and a7R III (our favorite and most recommended AF mode on Sony cameras), as well as Zone and Expand Flexible Spot. Sony specifically mentions its Sony Alpha A-mount lenses in its press release, but we've tested it with adapted Canon mount lenses as well and can confirm it works with EF lenses via a Sigma or Metabones adapter. Since Eye AF also works with adapted lenses, we're really starting to see less and less of a downside to using third-party lenses on Sony cameras, save for a significant drop in performance at longer telephoto focal lengths.

Another stand-out feature added in the updated firmware is 'Aperture Drive in AF'.* This offers two options for aperture behavior during focusing in AF-S: ‘Standard’ opens the aperture up (up to F2) for focus acquisition, while ‘Silent Priority’ always forces the camera to focus at your shooting aperture to minimize the sound of the aperture opening during focus acquisition.

Sony warns though that ‘Auto Focus may become slower when Silent Priority is selected’ – precisely the reason why we've been asking Sony to add a mode where the camera always focuses wide open in AF-C, at the very least until shutter actuation. This new setting adds the option to do the exact opposite in AF-S, and doesn’t change behavior in AF-C (where newer Sony cameras always focus at the shooting aperture). We urge Sony to add a 'Focus Priority' mode that always forces the camera to focus wide open in AF-C, as DSLRs do.

Firmware version 2.0 for the Sony a7 III and a7R III also improves the overall performance and stability of the cameras, and offers a few more stand-out improvements:

  • AF Track Sensitivity is available as an option for custom key settings
  • Enables bracket shooting in silent mode
  • Fixes exposure issues when using flash alongside flickering light sources
  • Better handles continuously shot photos as groups when browsing in playback

Note that many of these improvements came to the Sony a9 in previous firmware updates, so it's nice to see similar improvements to the rest of Sony's Mark III lineup.

* For 400/2.8 GM, 24mm/1.4 GM, and future lenses