I just found this over on Andrew Reid's site. Initially thought it might be an April fool's joke - but apparently not. The images from the camera look amazing (my non-technical evaluation!).

http://www.eoshd.com/2017/04/super-35mm-4k-comes-canon-5d-mark-iii-new-magic-lantern-module-real/

The Canon 5D Mark III will now record 4K, raw thanks to A1ex and his team at ML. The resolutions available are: 1920×960 @ 50p (both 1:1 crop and full-frame – 3×3 pixel binning) 1920×800 @ 60p (same as above) 1920×1080 @ 45p and 48p (3×3 binning) 1920×1920 @ 24p (1:1 square crop) 3072×1920 @ 24p (1:1 crop) 3840×1600 @ 24p (1:1 crop) 4096×2560 @ 12.5p (1:1 crop) 4096×1440 @ 25p (1:1 crop)

Limitations currently exist, of course (no sound is recorded and B/W display) but recording time seems very useful (no limits quoted, if they exist.)

Follow link below....