Kai from DigitalRev TV mentioned this in the latest video, when talking about the video of the 1DX Mark II...
"But it doesn't have LOG. C-Log. Whatever they call it. If you want a 4K Canon, I'd probably wait for something else... something ending with... Mark 4. Possibly coming out around Photokina time."
https://youtu.be/qx4BmzWghC4?t=702
I wonder if Kai already knows the 5D Mark IV has C-Log 4K video? Or if it's just his estimate? It certainly sounded like he knew it for a fact though.
"But it doesn't have LOG. C-Log. Whatever they call it. If you want a 4K Canon, I'd probably wait for something else... something ending with... Mark 4. Possibly coming out around Photokina time."
https://youtu.be/qx4BmzWghC4?t=702
I wonder if Kai already knows the 5D Mark IV has C-Log 4K video? Or if it's just his estimate? It certainly sounded like he knew it for a fact though.