Issue with white balance and color calibration on Darktable 3.5 (master)

[priort (Todd Prior)]

Well discussed here in and around Nov and Dec time frame

Introducing color calibration module (formerly known as channel mixer rgb)

I hope the Channel Mixer will stay. It’s a module that any other software I know uses. Renaming it would be strange and would certainly raise an eyebrow for anybody that uses any other photo editor. A separate color calibration module would be great. I didn’t see any reference to any colorcheckers, hope the most basic ones will be included. Like in DaVinci Resolve (that is the free version). They have a preset matrix for 8 or so different colorcheckers (you can even use a cheap AliExpress one). …

Introducing color calibration module (formerly known as channel mixer rgb)

I just tried that image. The CAT relies on the usual white balance to correct the image to D65, so that the color input profile gets predictable. But for the Sony from that picture, the red white-balance coeff is 2.67, which is massive and probably wrong (most sensors are between 2 and 2.33). If you force a red coeff of 2.0 in white balance module, then retry the color calibration sampling from any grey patch, then it will work. Problem here is we stack the color calibration on top of white ba…

WB Module to D65-then input profile-then color calibration to D50…

Quoted from AP posting in the thread linked above
“Don’t even try to compare temperature readings from both modules. Again, color calibration takes an input that is already pre-corrected by white balance and input profile.”