Within a scene-referred workflow is there a preferred module that would allow for lightening or darkening of the “L” channel without affecting color?
I know that I could use the “tone curve”. I’m just not sure that it would be the right one to use.
Tone equalizer will do it.
The brightness adjustment of color eq is not too bad but I guess its a bit tedious maybe… I only tried a couple of times but if you expose the sliders and set them all to the same displacement the a and b channels don’t seem to move too much…
EDIT
No I just got lucky it can move color as well…
So, I guess that the tone equalizer is not the module best suited for holding onto a and b when lightness is tweaked?
Mike, you need to make sure you’re distinguishing between the change in tone vs the change in hue. The example you point to might just be the former, and not the latter.
If you wanted to quantify that, you might try extracting the RGB values of each patch and hand-converting them to LAB, looking for any difference in the A and/or B values. You can use either G’MIC or (I think) Imagemagick to do the LAB converions.
you might use a blend mode to limit the effect on lightness only. But since the module isn’t operating in Lab don’t expect a and b being unchanged in the color picker …
Here is a minimal pipeline (image credit: @Tamas_Papp ). No curves, no tone mappers, just white balance (the ‘legacy’ method, only a linear matrix operation), demosaic, exposure:
at 0 EV
at +1 EV.
‘a’ and ‘b’ went from (1.36, 4.23) to (2.70, 8.47) and then to (3.40, 10.67). I even set white balance to the ‘old’ method (no color calibration, only linear matrix operations).
1 Like