Comparing Rawdigger to Nikon Capture NX2


I am studying an image I made with a Nikon D600, comparing histograms and under/overexposure between Rawdigger and Nikon Capture NX2.

Rawdigger shows no overexposure and 9.2% underexposure in the blue channel. NX2 shows no underexposure but significant overexposure in the red channel. Can you help me to understand this? I was using auto white balance in the camera.

Some converters apply hidden

Some converters apply hidden exposure compensation to compress shadows and put (underexposed) midtone to the middle of tone range.

Adobe converters are known to do that:

I'm not sure about Capture NX2, because I'm not Nikon user (only Canon, Olympus and Sony), but it is easy to  investigate: just shot gray field, measure it using RawDigger (distance between gray values and saturation). Then process the shot in your converter (with all inputs at zero) and compare.

I have discovered that I had

I have discovered that I had inadvertently left "Active D-Lighting" on in the camera. That tries to lift the shadows in the RAW file and may explain the discrepancy.

There is one more twist.

There is one more twist. Nikon Capture shows the overexposure warning not over the raw data, but after the white balance is applied to raw data. So, if the overexposure is due to white balance, one can just apply negative "exposure compensation" in Nikon Capture until the warning is gone. However if the warning is only on the green channel and it is not gone after applying -0.33 in Nikon Capture it means that you may want to try a different raw converter.

Best regards,
Iliah Borg

Add new comment