Advice needed: Sony body working on canon lenses?


Aug 19, 2012
Tyrol, Austria
Hi Guys!

Can you give me some advice please. Out of guaranteetime, the sensor of my 7D Mk II has been broken and needs an expensive repair.
I saved some money and I am looking for an replacement for my second body. I am happy with my 5D MK IV, but for birding, the higher fps of the 7DII have been fine. More MP for cropping is wanted.
In an near nature reserve, I met an photographer who shot with Nikon and Sony. He used an A9 on an 100-400mm lens for fast passing birds, and I was surprised how fast it worked without any noise. He also told me, the new 7R will be fast and accurate in focussing too.
So, I am considering to give Sony a chance. Later, maybe an 100-400mm Sony or the rumored 200-600 Sony will be following. But definitively no 400 2.8 as it will burst my wallet (rumored price between 15-20000$)

My question: I know, there are a lot adapters out there, but which works best on my 500mm&1.4x extender? I know, the fps will be lower, but what is about the AF?

Thank you a lot.


Sep 22, 2013
Wautoma, WI USA.
i have have the a7rii and have used canon, tamron, and sigma lenses along with the metabones IV and sigma mc-11 adaptors. in general: longer fl = poorer af. the new sony bodies are supposed to be better and work great with native lenses but i would stick with a canon body for canon supertele lenses.

a7rii/a7riii cropped to aps-c is about the same pixel density as 7dii. i would get yours fixed or get another one.

5dsr would give you full frame with the same density if you need it.


Mar 28, 2013
Sorry to hear about your 7DII but I have over the last two years shifted my emphasis to Sony now owning a A7II and hoping to upgrade in the future to a A7RIII or theA9 however I have lots of Canon "L" glass and what I have done is to use the Sigma MC-11 which works very effectively on most Canon lenses although it does not work on the 100-400mm f4.0-5.6 but does work on the 70-200mm 2.8 very well. The good thing about the Sigma adapter is that Sigma continues to update the firmware which you can download directly to the adapter. Sony is expanding their lens line but they are very expensive. Recently I bought the F4 24-70mm L lens and it has become my general carry around lens. I shoot mainly landscape. I hope this is helpful. Good luck with your decisions. I have learned to love the product albeit it very complex and has capabilities beyond my level of expertise but learning every day.


EOS M6 Mark II
Feb 4, 2015
I use the a7r2, Metabones IV adapter and a Canon mount Sigma 100-400 and it performs better than I expected.
I just figured out that the Sigma has push/pull as well as a rotating zoom.
I would expect that the a7r3 or a9 would be even better than the a7r2 for AF. I use the metabones adapter with that Sigma and Canon lenses without issue.


Nov 17, 2011
IF you plan to shoot with Sony A9 or A7r III, I would HIGHLY recommend native FE lenses.

I'm currently shooting with A9 and AF tracking is SUPER. I had Canon 1Dx in the past and I can say A9 is a better.


May 8, 2015
1) Sony's own 100-400 works better than any adapted lens, let alone with an additional converter. Especially compared to coming from an APS-C camera, you'll find the 'bare' Sony lens gives you about as much resolving power as the longer Canon lens on the APS-C body. You can skip the adapter and the teleconverter and you'll still have the detail you're used to.
2) Stacking any teleconverter on top of a mount adapter is generally a recipe for failure if you want AF to be any good. With an IS lens like your 509mm it'll also murder the battery double fast. If you shoot for ~400 frames, less than 1 hour or so, and the birds you're chasing are of the larger and slower variety (e.g. herons, geese, some of the more placid eagles), it'll be fi e. If you shoot more/for longer, or simply faster or smaller/twitchier birds, you're going to want to either give up the teleconverter, turn off IS, or keep to native lenses. (See #1.)
3) The 7D mk III is due out within the next three or four months. It will undoubtedly have more resolution, a deeper buffer, more effective AF tracking, and a faster burst rate than the 7D2 you've been using, and in most cases the 5D4 too. (Good chance it won't quite match the 5D4 for total pixel count, but it'll still beat it for pixel density, which is what really matters.) Best of all, all your current gear will work with it perfectly.
4) If you really want to switch from Canon, and you're not sold on the Sony's 100-400, the Nikon D500 and their lenses will serve you better. I really love the a9, but if 500mm+ is what you want, Nikon is currently the #1 and Canon is #2; Sonys have gotten much better with adapters, but anything of that kind of length—and again, let alone with a teleconverter on top—and the tracking and battery life go right down the toilet.

What I suggest you do as your first move is think about whether you can wait for the new Canon or not, and if not, just rent an a9 and 100-400 for a weekend and see how you get on with that. That native combination is great and easily produces the results of your existing 7D2 and 500mm, but with even better focus and faster burst rate. If that image quality isn't enough for you, rent the Nikon native combo next. You're talking about some serious gear, so it's worth actually trying all the options out before going through the hassle of switching systems. It's not fun spending the time and money switching only to find out you still don't get the results you want/have a whole new batch of problems to deal with that you weren't expecting. As a user of Canon, Sony, Nikon, Fuji, Phase, and Mamiya myself, I could never advise someone gambles on switching systems without spending a good few days testing that system first.
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