So, having nothing better to do after raking leaves, I set out to produce a whitebalancing camera profile. Starting with my target shot raw file from last year’s profiling, I opened it in rawproc using the rawdata property, so I started with the camera data straight out of the NEF, converted to floating point, no assigned camera profile. I demosaiced it with half, then cropped to the target corners and saved it. Absolutely no processing except convert to float, demosaic. Here’s a screenshot of it:
Next, I ran it through the bash script I wrote for last year’s profiling:
PATH=$PATH:/d/Documents/Argyll_V1.9.2/bin
scanin -dipn -v -G1.0 -p $1.tif /d/Documents/Argyll_V1.9.2/ref/ColorChecker.cht /d/Documents/Argyll_V1.9.2/ref/ColorChecker.cie
colprof -v -am -u -C"No copyright, use freely." -O"Nikon_D7000_Sunlight_UniWB.icc" -D"Nikon_D7000_Sunlight_UniWB.icc" $1
That produced an ICC profile that I then assigned to my reference train image upon opening. Same treatment: rawdata, demosaic; to that I added a colorspace conversion to Rec2020 g1.8, and a scaling to put black and white at the data container limits (a poor man’s display transform). Here’s a screenshot:
I used to have to tweak white balance to get this. It’s still a tad blue, but based on what we’ve been discussing, I think it’s due to the shooting of the target in good, bright sunlight, and the train was shot on a cloudy day, n’est ce pas? On second thought…
I’d shot multiple exposures of my target, and using the one I’d used for my original camera profile produced a bit of garishness (NOT GREEN!!!). On inspection, the white patch was a bit blown out, so i moved to the next lower exposure, re-produced the profile, and 'ere y’go.
You can read and read and read all the prose out there on color management, but there’s nothing like a good example to drive things home. @pixelator, thanks for letting us hijack your thread. @Elle, @gwgill, @anon11264400, thank you for the discourse…