Registered: Dec 31, 2001
Total Posts: 22190
Country: United States
FM member, stanj posted some Canon EOS-1D X RAW sample files, video links, and comparisons to the popular Canon 5D Mark III in regards to ISO performance.
Here are the links below:
Canon EOS-1D X Buffer depth videos at 6, 8, 10 and 12 fps
Canon 5D Mark III vs. Canon EOS-1D X amp glow test
High ISO still life Canon EOS-1D X vs. Canon 5D Mark III
Canon EOS-1D X vs Canon 5D Mark III high ISO test
Also, check out this thread from FM member, Stoffer, exploring his Canon EOS-1D X shadow recovery and dynamic range.