Roy P writes:
The latest firmware from Sigma for the MC-11 adapter (1.4) finally lets the Sony A9 to be used with Canon EF lenses. The A9 now works flawlessly with the Canon 70-200mm f/2.8, 100-400mm f/4.5-5.6L II, and 200-400mm f/4, even with the internal 1.4x extender. It likely works with shorter focal length lenses very well, too.
The focus accuracy with the A9 is excellent and tracking also seems to be working well at the high frame rates, but I have not tested the tracking for a subject that moves across the entire frame, or fast moving small subjects like birds in flight. The initial acquisition of focus is on par with a Canon 5DSR, may be just a hair slower. Definitely not in the league of the Canon 1DX II, which I am familiar with. The 5DSR rarely has to hunt; the A9 occasionally hunts. Both are way ahead of the A7R II, however.
So far, I have tested only with center AF. I don’t know if the other AF modes in the A9 can work with Canon lenses. Eye AF definitely does not – the camera gives a message saying it is not possible with the lens used.
Net-net, for anyone considering switching from Canon 5D models to Sony A9, the A9 will work with all their Canon glass just about as well as their existing Canon cameras, with the added benefit of higher frame rates, superior tracking, and most importantly, no blackouts. And the A9 is also better in some other ways – manual focus aids (focus peaking, live view), 4K video capabilities, ability to work with a much wider range of third party glass, etc. But some of the goodies the A9 provides, like Eye AF, flexible spot AF, and perhaps all of the 693 AF points, may not be available.
But for anyone who shoots with a 1DX / 1DX II, the speed of the initial focus acquisition is not quite there, and that means buying new and expensive Sony glass, and having to live with a very limited set of long focal length lenses for now. So it probably makes no sense for now.
DIGLLOYD: I have the about $249 Sigma MC-11, but I suppose I need to buy the Sigma USB Dock to get my MC-11 updated. I really dislike this trend to needing firmware updates for everything (cameras, cars, computers, etc), but I suppose it is inevitable and clearly it has an upside.
Roy P responds:
You don’t need the Sigma USB Dock (I don’t have one).
Just download and run the Sigma Optimization Pro app, connect the MC-11 directly to your computer when asked, and it upgrades the firmware. For whatever reason, Sigma doesn’t clarify this!
The Windows and Mac versions have different sub-version numbers (1.4.1 and 1.4.0). Only minor nuisance, you need a USB 2.0/3.0 cable with the smallest connector.
DIGLLOYD: excellent tip! I was not aware of this.