BTW, the 5DIII has excellent DR. 14 bit compared to 12 bit on earlier models. For video, wide DR will usually get you into trouble when you start editing your clips and compressing for DVDs. HTP will get you closer to that compressed DR needed for video work.I think 5ds file of any generation would fit nicely into a 12bit file without any loss.
The 5D Mark III has MUCH more highlight headroom and MUCH cleaner shadows than the 5D Mark II. I've extensivly compared both and carefully studied both of these aspects for a review website.
Your camera is deffective or you are mistaken. You also might have the camera set up wrong such as auto lighting optimizer set incorrectly.
I agree... if your dynamic range is worse than the 5D Mark II, something's definitely wrong with either your camera or your processing.
That is if he was shooting above 800. Otherwise there wont be any difference between mk2 & mk3.