Metabones, best known for their magical lens adapters that actually make cameras more sensitive to light, has added another adapter to their micro four-thirds lineup. Along with this new adapter, (aimed at users of the Panasonic GH4) autofocus functionality will now be available for certain Canon adapters as well.

As a GH4 video shooter myself, I don't often use the autofocus, but there have been a few times where it would have come in handy. Using Lumix lenses like the 12-35mm f/2.8 IS work well enough, but aren't at the same level as say, a 24-70L II 2.8 from Canon.

A recent press release from Metabones included the following list of adapters that can now use autofocus, after installing the new firmware:

Canon EF to Micro Four Thirds Speed Booster Adapter (model number MB_SPEF-M43-BM1)

Canon EF to Micro Four Thirds Speed Booster S Adapter (model number MB_SPEF-M43-BM2)

Canon EF to Micro Four Thirds T Speed Booster XL 0.64x Adapter (model number MB_SPEF-M43-BT3)

Canon EF to Micro Four Thirds T Speed Booster ULTRA 0.71x Adapter (model number MB_SPEF-M43-BT4)

Here is a link to the firmware on Mac and Windows.

My buddy Jaron over at ResourceMagOnline told me that he has tested the firmware update on his S Adapter with his GH4, and autofocus worked for both video and photo, but the speed of the autofocus in video mode was rather slow (like on most compact DSLRS with native lenses).

The previous version of the M43 Speed Booster.

As for the latest adapter being offered, it is being called the "Canon EF Lens to Micro Four Thirds T Speed Booster ULTRA 0.71x," or just Ultra for short. It provides a 1 stop increase in light sensitivity, and a change in focal length by 0.71x. Besides coming with the autofocus support mentioned above, I don't see too much difference between this new model and the original Speed Booster (the model I own personally, which is now listed as discontinued) so as far as I can tell, this new Ultra version might be more of an update, rather than a brand new product that will stand beside the original and offer something markedly different. This is all the Metabones product page will tell me:

the new ULTRA design makes very effective use of exotic materials at the furthest limit of glassmaking technology, and as a result is almost perfectly corrected for use with all fullframe SLR lenses regardless of aperture.

In any case, as a user of these products, I can tell you that they are well worth checking out if you own Canon glass and want to get into video production with a Panasonic GH4. It's become a mainstay in my own kit, and I've written about how the Speed Booster affects different lenses, from the standpoint of focal length and maximum apertures, in this article here.