I am going on holiday soon and my sister and I will be making a film og our trip. She will be using a canon 80d and will be filming in 1080/60 which is fine, since we will be slow-mo'ing most of our footage in the film. I am using a canon 5d mark iii which can only film i 1080/25 or 720/60. But my question is, would it be a problem to mix 720 with 1080 footage? And what would the end result look like, if i fx uploaded it to youtube? I will be editing in FCP X.
Another question if anyone knows, what FOV would be best to use on a Gopro hero 5 black, so that it looks good with the dslr footage?