This one is defeating me currently.
I’ve just gone through scanning 7 films from negatives, which I took with my Pentax MZ-50 during a 1999 trip to the UK. The scanning has gone pretty well with VueScan and now I am using PhotoLab 4 to whip some of them into good enough shape to share.
Where my trouble lies is with the “white balance”. I am able to use the eye dropper to pick a neutral tone and the photo ‘snaps’ to a sensible looking image, but what is actually going on when I do this?
With a RAW file from my DSLR, I can use the dropper in the same way and then choose to ‘juice’ the photo a little by warming or cooling it with the white balance temperature slider. For an “RGB” image like the TIFF scanner files, the blue-yellow slider is still there, but after using the eye dropper, as soon as I touch the slider, the colour goes back to original and I’m not sure the colour I achieved with the eye dropper is reachable just using the slider. It seems to be a whole different set of colours.
Furthermore, without recourse to the white balance slider, what is a technique to “warm a photo” using other PhotoLab blocks?
I realise, having done all the scanning, I could probably profile the films to get better colours in the first place, but I would still like to understand how to do this warming or cooling.