Tone Equalizer Question

[gadolf (Gustavo Adolfo)]

Also, it may not satisfy you, but I think it explains the reason:

A tone equalizer in darktable ?

Nothing is going wrong. The guided filter is applied iteratively 2 or 3 times on top of itself, depending on the preset you choose. Depending of the feathering factor used, the guided filter tends to average the luminance piece-wise, thus compress the histogram around the average luminance of your picture. [Screenshot_20190924_110347] To compensate for that, in the masking tab, you can use the mask exposure and contrast compensation. The exposure compensation will slide the histogram to the le…