is a photo and video supplier out of California that specializes in underwater gear. They gave the Canon 1DX a spin to see what the 4K video can do. Let me just say, it looks amazing. In their words: "With excellent low light abilities and 4K 60p video, you can be sure this is the camera the pros will be shooting for a while."
This video will give you a pretty good idea of what the 1DX is capable of. Unfortunately, they don't mention which lenses they used. Anyway the video is really beautiful and you can check it out below.
Canon 1DX Mark II Camera First Dives Underwater from Backscatter on Vimeo.