Yes, that is clear
I don’t quite agree, but see below.
That is also clear
That is clear as well.
That is also understood
Hence why I proposed a zoomable interface for the advanced tab, so that we are not stuck with nodes that are 1EV apart. That way you could disregard those “long tails”. Contrast compensation is there for that reason, but if used agressively, will create artifacts and mess up with the guided filter. What @kofa suggested is so far the best solution for me, although it’s not perfect, since you can only use the module that way via shortcuts and not through the GUI.
Agreed
Very often. I try to use the module based on what @anon41087856 shows here, and he uses the module on the whole image:
Module usage could be summed up in the following 3 usecases:
- For increasing contrast, as long as you don’t care about also increasing local contrast use no filter.
- For increasing contrast while preserving local contrast, use guided filters (I won’t go into the differences here).
- For compressing dynamic range while preserving local contrast (which I believe is one of the most important usecases, and most of what @anon41087856 demonstrates in the video) use guided filters.
The part of the image where you do any of the 3 is up to you. The problem is that, say you want to focus on a very specific region, like the shadows of the image (leaving noise aside, I mean the actual darker parts of the image that you want to affect). To expand the histogram and have more nodes to control them you need to increase mask contrast and adjust mask exposure accordingly. The problem with that, is that the mask will start to fall apart quickly, creating artifacts. But if you don’t increase contrast you don’t have enough nodes.
Now, let’s look at what happens in each of the three usecases, when boosting the contrast enough to focus on only the shadows, for example:
- Increase global and local contrast, no GF: there is no contrast compensation, so no problem.
- Increase contrast and preserve local contrast, GF: Possible artifacts.
- Compress dynamic range and preserve local contrast, GF: Possible artifacts, and if you compress DR in areas with too similar lightness value, the GF can only do so much, local contrast will decrease (although probably not as much as with no GF).
That’s why, despite what @kofa just showed us, I believe that, and if the technical difficulties are indeed solvable (proportionally scalable nodes), having a zoomable interface in the advanced tab instead of fixed nodes as well as a real histogram in the masking tab could be a good solution. If there is no contrast compensation, in theory, contrast wouldn’t mess with the guided filter, hopefully minimizing/avoiding the artifacts.
If not, the shortcuts he showed us, already make the module much easier to use for me.
Cheers!