Continuing the discussion from Tone equalizer vs tone curves:
I use the tone equalizer a lot and find its results to be fantastic much of the time. But something that still baffles me sometimes is the masking, especially when the colour pickers for exposure comp and contrast don’t help.
(tagging @obe who also claims to have this issue frequently)
Based on the manual and Aurélien’s videos, our goal is to stretch the grey bar under mask post-processing to fill the space as much as possible. This should make the mask cover as much of the tonal range as possible. It makes sense and often works as expected. But sometimes we get a very flat histogram in the advanced tab.
Why is this? What is the histogram showing when this happens?
Here are examples of a bad mask and good mask:
Based on the image with mask display turned on, it’s clear that the good mask in the second example is superior, there is more blurring and greater separation of tones. This is reflected in the histogram in the advanced tab. But, the grey bar in the masking tab is very much bunched up towards the highlights, which would make you think your mask was not good.
In the bad mask, the grey bar in the masking tab would seem to indicate you have good spread over the tonal range, which is obviously not the case from the image and from the histogram.
So, my question is not how to get a good mask, but rather trying to understand what is happening between the grey bar and histogram. The bad mask is very contrasty, with large areas of highlights and shadows, so I would expect the histogram (which I know is the mask, not the image) to show two peaks, one at the left for the shadows and one at the right for the highlights. This would still be a bad mask because it ignores midtones, but it would at least make sense with the masked image. But instead, the histogram just shows a slight bump in the highlights region.
And conversely, in the good mask, why is the grey bar under mask post-processing bunched up and not reflecting the decent spread of tones?