Raw histogram calibration for the Nikon D800E
I have good news and bad news.
The good news. The UniWB calibration procedure I’ve been working on went swimmingly with the 800E. The whole thing took five or six minutes (I’ve been doing this a lot, so I’m faster than the average bear). Four exposures, three Rawdigger analyses, and one look at the EXIF data. The RGB values in the final shot were within +/- 1 percent.
The bad news. The Nikon WB coefficients were the same after white balancing to the R=G=B image as before. I thought maybe the camera was silently rejecting the white balance image because it was too dark, but I made a series of white balances with images each with progressively one stop more exposure until clipping, and all had the same coefficients.