Le 26/10/2018 à 00:49, Jason Polak a écrit : > Dear Aurelien, > > It's clear that you put a lot of thought into this and I am eager to try > it. It is very helpful to see the GUI screenshots, and based on those I > do have a few comments/questions: > > 1) Don't you think that the equalizer/local contrast module are more > similar to the sharpening module rather than the tone curve/fill light > module? Especially with the equalizer, part of it performs a very > similar effect to sharpening. I understand though that the algorithms > behind them might be different.
There is still a certain amount of arbitrary choices in this order, I won't deny it. Local contrast, at a very local scale, is similar to a sharpening, but it's a perceptual sharpening (you fool the eye), not an optical sharpening (you don't restore blurry edges). Even with a tone curve, if carefully adjusted, you can increase the feeling of sharpness, as a side-effect. But local contrast stays contrast, and as equalizer and local contrast can affect the global contrast dramatically (the same way as shadows-highlights), I put them with tones. Sharpen is a sort of high-pass filter so its effect will always be more selective. Besides, local contrast and equalizer are best used before high-pass and sharpen (retouch from more global to more specific). > 2) In your description of the correction tab, you say that after leaving > this tab, the image should look clean and dull. That makes sense - > though I am wondering how this works considering the automatic > application of the base curve? If the base curve is applied upon image > opening, the tones of the image look already pretty manipulated compared > to the dull-looking image without the base curve. In other words, it > seems as though having the base curve applied can already push the tones > in the image pretty far, leaving little room for colour balance > adjustments later on in the tone-modules tab. I believe the basecurve is a mistake and should be deprecated. First and foremost, it's applied before the input color profile, so you have to disable it if you work with an enhanced/custom matrix, otherwise your profile is useless (never add contrast before the input color profile, do a gamma or log correction but don't darken blacks while you light mid-tones). The basecurve was intended, at first, to emulate in-camera JPEG color-rendition with filmic curves <http://filmicworlds.com/blog/filmic-tonemapping-with-piecewise-power-curves/>. Turns out the quality of the users-provided curves is not equal from brand to brand, it creates out-of-gamut colors and over-saturation (on Nikon, the reds get boosted like crazy - people all look like alcoholics) and the devs have stopped adding new curves a few years ago. The new module for that purpose is the colorchecker/LUT, which can "easily" be used by anyone to create custom LUTs from color charts and in-camera JPGs and occurs later in the pixelpipe, where it is safe. The base curve can still be used to (carefully) tonemap HDRs from a single exposure. But do yourself a favor, buy a colorchart <http://www.colorreference.de/targets/index.html> (30 €), make your own camera profile <https://encrypted.pcode.nl/blog/2010/06/28/darktable-camera-color-profiling/>, and never ever use the default base curves. > I am just wondering how having a default base curve fits in with your > editing paradigm? > > Sincerely, > Jason Thanks for your input, Aurélien. > On 2018-10-25 08:28 PM, Aurélien Pierre wrote: >> Hi everyone ! >> >> To follow up on that matter, I have done a pull request doing what I >> discussed here : https://github.com/darktable-org/darktable/pull/1745 >> >> You will find screenshots showing the changes, a sum-up of the benefits >> and a poll to vote for/against the change and give your feedback. After >> that, I suppose the core devs will decide what they want to do. >> >> I know it's still not the flexible UI some of you asked, the problem is >> we don't have the workforce for it. darktable 2.6 is supposed to be >> released in 2 months, so now is not the time for ground-breaking >> changes. This is intended to make things more logical (or less bad) >> using realistic means. I changed 30 lines of code, so I'm pretty sure it >> won't break anything. >> >> Cheers, >> >> Aurélien. > ___________________________________________________________________________ > darktable developer mailing list > to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org > ___________________________________________________________________________ darktable developer mailing list to unsubscribe send a mail to darktable-dev+unsubscr...@lists.darktable.org
