Backscatter removal in Darktable

Hi all - Darktable newb here running Darktable 3.0.1 on Ubuntu 20.04 LTS, shooting RAW on an Olympus TG-6. I do underwater shots and have been thrilled with Darktable, especially the dehaze, white balance, and local contrast. What I am struggling with is backscatter issues (typically particles/flocculants in the water, which is very common). I know LR addresses backscatter pretty well, so I am compelled to believe Darktable can as well.

For starters I’d suggest you find a more recent version. There have been a lot of changes between 3.0.1 and the latest version (3.8.1).

Ok, up to version 3.8.1 now. Did a search in the help files for backscatter and did not get any hits. Went through the modules and they are working better in this version, although not seeing anything that directly addresses backscatter. Perhaps I am using the wrong term?

Can you post an example image?

Could this be relevant? There, the issue was condensation on the lens, but maybe a similar approach could be used:


P4100065.ORF (12.2 MB)
Here you go. Particles around the subject and between subject and camera

Looking at your raw file reminded me of a Youtube video from Pat David.

Darktable’s retouch module has a wavelet decomposition function. Perhaps a combination of Darktable and Gimp can get you an acceptable result. Make this into a Playraw and see what others here may be able to accomplish. Good luck!

Will check it out. Thank you!