What causes these 'hot' pixels?

I am using RawTherapee Dev 5.8-3049 and on a recent photo I noticed some ‘hot’ pixels in the jpg output. They are not present in the preview. The image color was significantly tweaked so I am not sure if this is an actual bug or just a matter of going too far.

Here is the raw (for trouble shooting purposes only).
DSCF2410.RAF (20.2 MB)

Even if I push the manipulations way too far I’m not able to reproduce this:

Here’s the quick, over-the-top edit for the above image:
DSCF2410-4.jpg.out.pp3 (15.8 KB)

I’m all but sure that we did not use the same modules/settings, though.

If this does happen to be a RawTherapee snafu it might be a certain combination of modules and/or settings. Are you willing to share your sidecar so we can have a look? This might just be, as you mentioned yourself, a case of pushing it too far.

Oops, I meant to post it a well. :roll_eyes:
DSCF2410-3.jpg.out.pp3 (24.9 KB)

The culprit is the second Local Adjustments spot.

If you turn on the preview deltaE for that spot and zoom in to 200+% the wrongness shows up. If I look at a normal, screensize view then I do have to say that the shape/mask is rather harsh…

You use 1 spot to mix 2 tools, each with a different scope. Not a good idea. If I make a duplicate of the second spot, remove tool one from the original and tool 2 from the copy the issue is (all but) solved. The image still shows a few single discoloured (“hot”) pixels, but I’m sure that is due to pushing things. I’ll leave the fine-tuning up to you :wink:

Here’s you adjusted sidecar:
DSCF2410.RAF.pp3 (24.5 KB)

And a screenshot:


Thanks. That was it. I just got rid of the expose adjustment entirely for the second tool.