Hi,
I just noticed there are two methods of applying automatic levels in darktable, and they give different results. I am curious about why. The manual does not mention the difference.
First method:
Start with Levels module reset and turned off.
Press Auto button below histogram.
Second method:
Start with Levels module reset and turned off.
Select mode: automatic
In this image, the left half of the image is done with the first method, and the right half is done with the second. No other differences.