Yes, the Canon EOS 5D Mark III does video. It offers three different video resolutions: Full HD (1920 x 1080) at 30 fps or 24 fps, HD (1280 x 720) at 60 fps, and SD (640 x 480) at 30 fps.
The Mark IV offers DCI-4K video. The two middle models can capture video in FullHD, though. We have video footage captured with the Canon EOS 5D Mark III and Canon EOS 5D Mark IV below.Dual Pixel CMOS AF III; New and more advanced AF system (compared to EOS 5D3) 4k video; Anti-flickr technology (seen first on the 7D Mark II) Improved video features; Crop mode (featured on the upcoming EOS 5Ds) ISO 100-51200 (H1: 102400, H2: 204800; And here are the newest rumored specs from Northlight Images (which Canon Watch has given a 50% Video quality and features. Canon was well aware of how much the 5D Mark III was used as a video recording tool by both amateurs and professionals alike when they were creating the Mark IV, so it’s no wonder we see a lot of improvements in this particular area. The first and the obvious one is the upgrade to 4K resolution at 30 or 24 fps. It I did come across this video with some slow mo shots in it: Here the poster claims they did a 1920 x 1080 full HD 60 fps in the description, using a Canon 5D Mark III with magic lantern. In the comments, he mentions that if your card is fast enough, it can do 10 seconds of slow mo as he was able to. However, I don't see anything online to