How to Shoot 4K on the Canon 5D Mark IV
On the new Canon 5D Mark IV, it is remarkably easy to shoot 4K video.
Press the menu button, then toggle over to Camera Menu 4. There you will see Movie Rec Quality, which you should select. Choose MOV instead of MP4 to access the full range of resolutions, and then choose the resolution and frame rate pairing that best suits your needs.
The Canon 5D mark IV records 4K in a large, relatively uncompressed codec. Make sure that you have a large, fast CF card to capture all of this data.
All-I is a shooting mode that preserves as much data as possible within each frame of video, while IPB is a much more efficient, compressed mode that will take up less space at a small quality loss.