Sigma has done well to provide a native solution for using its Canon/SA mount lenses on e-mount cameras. I'm sure owners of a7Rii and a7ii, and future owners of the a6300 will be thrilled.
As an owner of an NEX-6, I am quite eager, as many owners of a6000 would probably also be, to know if the new adapter will help Sigma lenses achieve AF-C as well quick AF-S on these older OSPDAF-equipped cameras.
The following quote from Sigma USA (emphasis mine) doesn't give me much hope:
“There are many challenges to designing high-quality mount converter and topping the list is aptly handling phase detection AF in newer cameras and this is where the Sigma MC-11 is groundbreaking in its support for the Sony E-mount systems,” states Mark Amir-Hamzeh, president of Sigma Corporation of America.
Will the older cameras be able to achieve reliable AF-S? Will it be quick? I don't think we should hope for AF-C support, but even single-shot AF would go a great distance.
I'd surely like to hear Entropy512's views about it. I'm sure he's happy that Sigma have not gone down the path of emulating the LA-EA1/3 adapters, but have decided to emulate a native e-mount lens.
Unfortunately, there's too little information, worse, it seems inconsistent.
I'm fairly certain that I've never seen DMF support from an EA1/3 emulating adapter. I need to double check this.
I'm also fairly certain that EA1/3 emulation doesn't support lens profile reporting.
So that's two claimed features I am fairly certain are hallmarks of native lens emulation.
Then they put up that compatibility chart that says no AF-C - another typical hallmark.
I know I've seen at least one person comment that, way back in the day, the order of things was something like:
- Sony and Sigma released a bunch of native lenses
- Sony added OSPDAF to some of their bodies
- These bodies needed lens firmware updates to gain OSPDAF. The DN trio never saw such an update
- Sony eventually added a firmware update to some bodies that permitted limited OSPDAF with "old" native lenses. - This is why the Sigma trio has center PDAF only on A6300
Problem is - I don't have any old lenses, so a lot of it is hearsay. I also can't find any claimed information from Sigma as to the performance of the existing DN trio - do they claim AF-C capability for those, or do they say no AF-C? If Sigma considers these lenses as not supporting AF-C, then that's some evidence that the MC-11 may have similar capabilities to the current DN trio (19/30/60) in terms of native lens emulation.
I'm right now debating whether I want to spend the money on the adapter to poke at it, or wait to see what happens when someone plugs an "unsupported" lens onto it. Sigma's compatibility page at
http://www.sigma-global.com/en/lenses/cas/product/accessories/mount-converter/ has a telling remark: "Note *2: Accurate operation is not guaranteed with lenses not listed as compatible" - which implies that with an unrecognized lens, it will attempt to go into some sort of fallback mode. My guess is that the best chance of success here will be primes with slower focus motors (like the 50 STM). If anyone reports OK success with that, I'll be buying one of these to throw on the logic analyzer.
Another thing I can't figure out:
They talk about using the USB Dock to update the converter. But they didn't announce an E-mount USB dock...
Oh, another piece of info of note - the lenses listed as DMF-compatible are the ones that also are listed in
http://www.sigma-global.com/en/lenses/cas/product/accessories/usb-dock/ as having configurable Full-Time MF settings. (Except for the 50-100, but I suspect that's just due to the USB dock page not being updated...) (Edit: My guess this is a focus-by-wire vs. traditional focus thing. I need to spend some time this weekend re-verifying, but I recall that when the focus ring is turned on a focus-by-wire lens, all of my adapters report a changing motor position. When I turn the ring of my EF85/1.8 USM - I don't see the motor position change in a logic analyzer trace.)
