Nikon D4 High ISO RAW
Nikon D4 RAW Image Quality
We used to convert RAW files used for comparison crops with dcraw, an excellent freeware raw converter. Unfortunately, dcraw's author has not been providing timely updates lately, so we have switched to using Adobe Camera Raw with its noise reduction and sharpening options set to zero. We've found conversions made with ACR to be almost identical to dcraw, when dcraw's demosaicing option is set to match ACR's method.
Below are crops from Nikon D4 RAW files compared to RAW files from recent pro-grade digital SLRs:
Looking at the crops above, the 12.2-megapixel Nikon D3S is still slightly better than the 16.4-megapixel D4 in terms of high ISO noise at the pixel level, however keep in mind that D4's pixel pitch is smaller at 7.3µm versus 8.5µm. The 16-megapixel Canon 1D Mark IV does not perform as well as the D3S or D4 in terms of noise, which is no surprise with its much smaller 5.7µm pixel pitch. Noise at the pixel level is higher from the 36.6-megapixel Nikon D800 with its even smaller 4.7µm pixel pitch, however its significantly higher pixel density offsets much of the noise when printed at the same print size, making the D800 a surprisingly good high ISO performer.
Note that the Canon 1D Mark IV is not a full-frame model like the others (it has a crop-factor of ~1.3x). We hope to add Canon 5D Mark III and 1D X crops here, once we get production models into the lab.