I'm shortly off on a month long trip round South America. I have a 70D and 80D and predominantly enjoy photography but will also do some video work. In particular, when in the Galapagos Islands, I will have my telephoto lens on one camera and something wider on the other so I can be reactive without having to spend time swapping lenses.
I will normally have a 10-18mm on one for wide shots and video (with Video Mic attached), and a 17-55 or 150-600mm on the other. Obviously a lot of the time it will be ONLY the 80D.
Question is... when I have both of them with me which do I use for the 10-18mm (video and photo) and which do I use for the 150-600 (photo only)? The 70D is new to me and I have never used it (not delivered yet); I got it predominantly as a backup, so have no experience to go off. I would place quality of photo as a higher priority than quality of video but I imagine the photo quality difference is far less than the video quality difference so don't see it as simple as using the 80D for my "primary" telephoto camera.
Which would you use for which, and any reason why?