Wowā¦ as @GMan mentioned a cool new feature hereā¦
ā¦just found that this PR has already been merged into master I played a little with it and it is really stunning to see this additional, subtle punch in sharpness it brings to the photo.
Thank you so much @hannoschwalm and Ingo Weyrich for this work. Awesome - and thanks for pushing darktable one step ahead again. It is so much fun to work with this wonderful piece of software Have a good time
Yes a very nice new feature, thanks to the authors! And a nice example of crossf-ertilization between darktable and RawTherapee, if I followed the story correctly
+1 . Many thanks to all those involved. I have given it a quick test and the results are very good. Probably the most natural looking āfineā sharpening in darktable at the moment.
Just to make it clear, as there has been some confusion: Lars found out in the AgX thread that capture sharpening has been merged into master; however, agx itself is under review.
Thanks to @hannoschwalm for his continued great work!
Yes itās great! Combining the subtleties of capture sharpening with the power of DoS is giving excellent results.
Iāve settled on a preset with 15 iterations, 1px radius, 0 edge sensitivity and 0.6px corner boost. Seems to work best on most images, but that is only tested with one camera / lens combo so far.
How did you land thereā¦I would guess the autocalculated one for the sensor was larger?? Was going smaller betterā¦ just curiousā¦its new and deserves some experimentingā¦
At first I didnāt realise the round button beside the slider was an auto button, so I manually adjusted, and found 1px to be the sweet spot. Much less seemed a bit soft, much more seemed a bit over cooked. Iāve tried on a variety of camera / lens combos now and notice the auto button typically gives between 0.6 and 0.8. The difference between that and 1px on many images is not greatly noticeable.
Ya I have just played a little from the documentation the value is supposed to be calculated when you first add an iteration and I think it suggested zoomed outā¦ I noticed that if I was at different zoom values the auto button gave a different resultā¦ I used some high radius with some restriction using the edge sensitivity which seems pretty much like the details threshold in the masking optionsā¦but as I said I really didnāt do much yet just some playingā¦I tried it on a recent play raw ā¦the coffee shop shot in the downtown thread ā¦you could really enhance the brick and mortar lines and these were good test points to look at as well as the small branches in the tree and leave at the top of the tree against the skyā¦
I would just like to add my thanks to @hannoschwalm for this addition to the demosaic module. Deconvolution sharpening is something I became aware of several years ago through commercial software (which I no longer use) and always hoped it would eventually be introduced into darktable.
I just downloaded the latest dev build today and had a little play with capture sharpening. Itās seriously impressive.
As per the PR:
āCapture sharpening (CS) tries to recover details lost due to in-camera blurring, which can be caused by diffraction, the anti-aliasing filter or other sources of gaussian-type blur.ā
For information to those of us who only run plain 5.2, could someone please post a screenshot of how the UI part of Capture Sharpening appears?
(Iām aware itās just a part of the demosaic module.)
I played a little with it and it is really stunning to see this additional, subtle punch in sharpness it brings to the photo.
Have a good time 
thanks @hannoschwalm for your work;