From Nikon Europe:
In this video pro-photographer, film maker, & director of DEDICATED, Corey Rich highlights why the D4S allows him to focus only on content and not the technology; the three most meaningful improvements made on the D4S; & how its features helped capture scenes that were previously impossible to capture. 'Hollywood crews could do this but not guys like me.' - Corey Rich.
Note from Sean: Oh my goodness! Why didn't I ever think to use Auto ISO when shooting video to compensate for transitioning from very dim environments to very bright ones (or vice-versa)? The EOS 5D Mark III works in the same way; it changes ISO on the fly when set to Auto ISO. The Nikon D4s's algorithm may allow for smoother ISO changes, but otherwise, the 5D III does the exact same thing.
B&H carries the Nikon D4s and the Canon EOS 5D Mark III.