Purple color instead of white/gray after importing Olympus E-PL1 photos

[FeralChild64]

Describe the bug

I'm using an Olympus E-PL1 as a "low cost trip camera" (I use it rarely - only for active trips when I don't want to risk breaking anything more expensive).
Today I have imported several RAW files and I could notice a very intense purple tint in areas which should be white or grayish - see the screenshot:

This is just an example - most of my photos suffers from the same problem. I have already used old versions of Darktable with this camera before, and there were no problems till now.

Steps to reproduce

1. Import photos from Olympus E-PL1
2. Go to darkroom, check the photos

Expected behavior

No response

Logfile | Screenshot | Screencast

No response

Commit

No response

Where did you install darktable from?

distro packaging

darktable version

4.4.2

What OS are you using?

Linux

What is the version of your OS?

Gentoo, AMD64

Describe your system?

No response

Are you using OpenCL GPU in darktable?

No

If yes, what is the GPU card and driver?

No response

Please provide additional context if applicable. You can attach files too, but might need to rename to .txt or .zip

Attached:

• RAW file
• JPG from camera
• Darktable screenshot

Opympus-problem.tar.gz

[pehar1]

Not a bug. You overexposed the sky/cloudes which leads to clipping. Use an appropriate highlight reconstruction method.

[FeralChild64]

Why the overexposed areas are now pink and not white anymore? This does not make sense to me.

BTW, indeed all the photos can be fixed by lowering the „clipping threshold” below 1.0, sometimes just slightly. This is very counter-intuitive, IMHO the defaults should be more sane.

[paolodepetrillo]

There are two different issues here - the magenta areas are overexposed but the purplish gray areas are not.

There is a known issue with Olympus white level that causes it to be set incorrectly, so that it doesn't detect the overexposed areas and highlight reconstruction doesn't work on them. Changing the white point to 4000 in the raw black/white point module would fix that. Fixing the white point has the same effect as lowering the clipping threshold in highlight reconstruction.

I'm not sure what is happening with the purplish color, it might be related to the way darktable tries to read and apply the camera's as shot white balance from the file?

[victoryforce]

Why the overexposed areas are now pink and not white anymore? This does not make sense to me.

This makes sense because this is what the overexposed areas actually look like before we apply some algorithms to them to get rid of the effect. Read this section on the documentation site.

[jenshannoschwalm]

Indeed a duplicate of the mentioned issue.

[Nilvus]

So better to close and if needed continue discussion on #392 issue.