Hi,
Why I was in the Dolomites with Hans Kruse's workshop we have tried out some of his Canon lenses on my A7RII with the Metabones. We did not check focus tracking just the ability to lock on. Focusing was pretty OK with the 16-35/4L and the 24-70/2.8LII, with the 100-400 LII it worked well up to 200 mm. Longer than 200 mm it did not find focus but went into slow hunting. Prefocusing manually it still snapped into focus.
My take is that a Canon shooter probably does better with a Canon 5Ds/5DsR unless he needs an EVF or the additional DR the Sony offers.
As a long time Minolta/Sony user I am not offended by the user interface, but I still feel some things don't make sense. I would like the user interface to be more "orthogonal" many limitations it sets don't make any sense.
I have essentially been very pleased with the camera and it is a great picture taking device and it works for me.
Best regards
Erik
I tried Erik's A7R II for a short while on both the Canon 24-70 f/2.8 L II and the Canon 100-400 f/4.5-5.6L IS II. My observation was that AF was considerably slower on the A7R II compared to the 5Ds R. The 5Ds R focussed instantly on both lenses. Especially from really out of focus it snaps in immediately. The A7R II was ok on the 24-70 for landscapes, but I'm not sure it would be ok for my way of shooting portraits. The 100-400 was an entirely different matter. The AF did not work well on longer distances for longer focal lengths like over 200mm. It would focus for shorter distances all the way to 400mm. As far as I know there is a newer firmware release for the Metabones adapter that should focus better.
The EVF on the A7R II was not my taste and would much prefer the OVF on the Canon. I prefer an uncluttered VF that is bright and clear and the 5Ds R has that.
Regarding weight of lenses, I sold my f/2.8 70-200 lenses and now only use the Nikon 70-200 f/4 VR lens which is excellent and is light at about 800 grams. On the Canon I use the Canon 16-35 f/4L IS which is excellent, but not quite the biting sharpness of the Canon 24-70 f/2.8L II lens. This lens weighs 800 grams and the f/4 is 600 grams so not much of a difference.
Regarding the Canon 24-70 f/2.8L II lens my observation is that my copy is in for repair at the moment since it had an unsharpness in the right hand side. The lens I have on loan via CPS also has a slight softness in the right hand side, so I'm waiting to see if the repaired lens has the weakness still of if it is a general thing with this lens.
Regarding the A7R II versus the 5Ds R, I would say that the Canon is a very fine example of DSLR design and has few defects in design and use. The well known lesser DR is for my landscape shooting only an issue in very early mornings with strong light from the sky and a very dark landscape and where the desire is to tone map it such that the deep shadows in the landscape will contain detail. The same applies for sunsets. For any other type of landscape shooting I have not found an issue with DR. So for the cases where DR is less than desired (which again depends on taste for post processing) I bracket and blend two (or perhaps 3) exposures using the HDR function in Lightroom. This works well and basically removes the DR issue for this camera (in my opinion) for landscape shooting.
So for choosing between the two cameras, if the use case is predominantly Canon lenses with auto focus, I my choice would be the Canon. If flexibility is needed to use many different lenses with adapters and a lot of manual focus needed and no fast focus is needed, then the A7R II seems like the obvious choice. If the EVF is highly favoured with lots of information in the VF then I guess the choice is easy too. Many more considerations could be added....