What is the reason for doing this? I recall that, at least sometimes, a blend mode is involved, but I don’t know if it always is, but even then, what does it accomplish that is desirable?
The passage you are referring to describes the role of the edges curve and how it handles edges…This is a older video. DT used to call it sharpness. But its a very good demonstration and explanation I think about what you are asking… specifically around 9 min give or take but the whole video is certainly worth a watch…Robert made some excellent videos a few years back https://www.youtube.com/watch?v=zzVXK4eAM5E
I think really what the edges is doing is much like this demonstration in photoshop, with the exception that the edges curve is applied via wavelets and this photoshop demonstration uses combined blending of sharpness with lightness and darken blend modes applied locally with a bush using a mask…This is a good demonstration though of the basic concept of applying sharpness and how it relates to contrast and halos esp along edges…and ways to mitigate it… https://www.youtube.com/watch?v=Slkj-Xz4nHM
Having seen effects vs. the settings in the videos, my conclusion is that with the luma and chroma settings in my example, the gradient reversals are so bad that a fully minimized edges setting is necessary to get rid of them. Possible, I suppose. The difficulty with trying to examine the effects is that when you zoom in to see better, you change the effects. Catch 22.
Edit: Maybe I am misinterpreting what happens when you zoom in. I dunno.
Your example makes it clear. Thanks. I wonder if there is some confusion of how edges works. As I said, I have seen this setting with completely minimized edges and thought do they really need that? The way to answer that would have been to reset edges to default and then looked for the reversed gradient problem. I was lazy and just thought I would ask instead.
I also see edges set to match the luma setting, but there is no relationship between the two, except by coincidence, so I just wonder if how edges works is really understood.
From now on, I will take the time to remove the edges setting and see if I can find a problem. Then put the setting back and see if it really corrects it.
Its really just to manage both and tweak as you like right… depending on the contrast you dial in you may have halos or you may have reverse gradients and the edges curve just gets applied up or down in an effort to reverse the effect of either depending on the situation and on your taste…I suspect very few people use it maybe because they tried it with no luma adjustment and so they would really see not effect of moving the curve even dramatically??
