why are some images shown with settings H S L, others with Jz Cz hz in parametric mask setting

Software darktable
#1

If have raw 2 images, taken less than 30 seconds apart in the eraly afternoon of a typical British day, late in the summer (i.e. cold and no shadows!), (ironically in the grounds of the home of calotype photography). One images shows shows options for ‘g R G B H S L’ when defining a parametric mask in the Exposure module; the other shows ‘g R G B Jz Cz hz’.

Why the difference ? Do I need to make allowance for this difference in my settings in this module?

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180827_Lacock_01.CR2 (11.4 MB) 180827_Lacock_01.CR2.xmp (9.6 KB) 180827_Lacock_02.CR2 (11.2 MB) 180827_Lacock_02.CR2.xmp (9.2 KB)

#2

It’s controlled by the blending options menu, the menu button to the right of the mask buttons. When it’s set to RGB (display) the options are “g R G B H S L” and when it’s set to RGB (scene) the options are “g R G B Jz Cz hz”. I’m not sure what determines the default setting.

#3

Its covered in the manual: https://www.darktable.org/usermanual/en/darkroom/masking-and-blending/masks/parametric/

3 Likes
#4

Your first one has the base curve so display referred wf and the second is scene referred so you are offered by default the matching blending channels…

#5

You’re correct- again!. I’ve lost count of how many times you have advised me of this fact; thanks for your patience. I have a brain which can skip whole paragraphs in a manual without realising it.