BD

You have likely made your choice by now, but FWIW, I have used several Canon bodies, and now own a a7s2 with metabones adapter. The autofocus is near useless on the Sony. That said, it's MUCH easier to do manual focus on the Sony. My biggest challenge on the Sony/metabones, however, is the metering. But, that's another discussion. Also, stills on a7s2? Insane. Amazing. Is a7r2 better, apparently, and that is astonishing. But, if you are shooting raw and understand LIGHTROOM post, any new DSLR, even a Rebel with good glass, will get you professional still images.

I'm shooting a variety of Canon lenses on my Sony A7s2 via a Metabones adapter (with latest firmware on both). The metering is all over the place in camera. I am aware that hooting in 4k may cause the LCD to darken to avoid overheating. But, this is not the issue. Has anyone heard of this? Are there discussions on the topic. Thanks for any help or direction on this issue.