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I'm not normally on Masto at this time, but just had a question.

In #GIMP3 the Lightness/Contrast tool appears to go *much* darker with one adjustment to contrast, compared to #GIMP 2.

I felt in G2, that the slider made smaller, incremental changes (and is easier for me to replicate than using curves because I don't always have steady hands).

Has anyone else noticed contrast being darker?

Is the only answer to use Curves/Levels?

Thanks,

FJ

@GIMP
Original screenshot before adjusting contrast in GIMP 3.
Adjusted screenshot after changing contrast from zero to one.
#GIMP #gimp3 @GIMP
GIMP
Here, i did see a difference, but when i turned off colour management in the view menu, i could no longer see a difference, and i think i had different colour profiles for the monitor. (i love your image in the screenshot!)

You could try expanding the Blending Options in Brightness/Contrast and reducing the opacity to 50% or so, to give you effectively half steps, maybe?
FibroJedi
I wish I could claim ownership of the image, but it's a screenshot I'm adjusting for a gaming blog.

Different colour profiles, hmm. With colour management turned off I get these images.

I'm going to see if I can reproduce the only-one-contrast on an older version of the GIMP AppImage.

It just feels like G3's contrast has bigger "steps" than G2.
Contrast 0 (the original)
Contrast set to just 1
FibroJedi
Oh I see what's going on.

To get the same level of darkness from "1 Contrast" in Gimp3, I had to set a contrast of 7-8 in Gimp 2.

So, is there something missing in how I've set up #GIMP3 that means it's making larger jumps in G3?

#GIMP #GIMP3

#GIMP #gimp3
GIMP
Not sure. is your image at the same encoding/precision (e.g. RGB 8bits)? Also check with colour management turned off in the view menu to see it's not a profile difference.
FibroJedi
1. I used the same image file in both tests, I just used different layers to display the outputs.But yes, it's RGB-8 set in 2.10 and 3.0.

2. Colour managing off made no difference.

I meant to dig into this while it was GIMP 2.99 but I just never got around to it. And I assumed I'd done something wrong, so "User Error" is not a "Bug" (with the software anyway, just...the user).
GIMP
it might be a bug, or at least a difference - please do feel free to file an issue; there's a link at the foot of gimp.org to file a bug, and we can look in more detail. Thanks!

In the meantime reducing opacity in Blending Options may be a workaround to explore.
FibroJedi
Aye, I will use your workaround for now. I'll leave the bug report as the one I did yesterday turned out not to be one because it was mentioned 1-2 years ago and I hadn't searched that far back before filing. I don't want to waste anyone's time.

Hopefully someone else will spot it and I can support it then.

But thank you so much for your time, I appreciate it.
GIMP
it’s not a waste of time - it helps us know it affects more people.

I did find this though - https://gitlab.gnome.org/GNOME/gimp/-/issues/13174

Brightness-Contrast tool always using linear light (#13174) · Issues · GNOME / GIMP · GitLab

Operating System: Windows 11 Description of the issue The "Brightness-Contrast" tool always operates in linear light, whereas in...
GitLab
FibroJedi
Now I need to research colour theory and how GIMP3 interprets light differently. I've tried using levels, but I was so used to how Brightness/Contrast works it was enough.

I've "thumbed-up" that thread. As it's a known issue, is there any point in filing it now?
GIMP
i don't know for sure it's the same thing, so if you hav more to add feel free, no point making a new report indeed. Thanks!
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