I have a photo that I’m interested to see what #software:darktable experts can do with…
The three things I wanted to do with this image which I feel I failed at was:
L1083176.DNG (53.6 MB)
This file is licensed CC BY-NC-SA 4.0 and NO-AI! 
For this image depending on the goal I guess but defringe was the worst option
Untouched…
Raw CA + CA modules
Lens Corr + CA
Defringe default…
Maxed out
Drop threshold but you now start to get yellow introduced… and the edge CA is still there just not a blue/purple
These two look great, but in the jpeg I posted I already use lens correction and the CA module. Could you please post your settings for how you achieved this?
The defringe module helped me with the tree trunk in front of the truck.
Sure no real edit even on the image…
Len correction and CA
I think i posted the xmp above… and I may have lost the other one but very similar just add raw CA and then tweak CA module…using the smallest radius necessary and the least amount of effect as you can start to desaturate a bit …though you can also add that back…
Hi Todd, I didn’t find any good settings, so I let the branches at the top retain the purple fringe: any attempt of removal reintroduced the nasty pink tint in the truck.
At the end I figured one may want to crop in a little so, as a fast test, I didn’t care.
Thank you for the tip! I didn’t know about the two TCA sliders but now I see what they do and finally the leaves look acceptable.
It still leaves areas where Defringe helps taking care of the final edges, though, so I still don’t think that module should have been deprecated (perhaps just a warning, like when you try to adjust the temperature in white balance module while also having the color calibration module active):
So now I’m going to investigate how the other people who posted here masked the truck. I’m crossing my fingers that there’s an alternative to manual masking which I haven’t discovered yet…
I think you introduced some problem while tying to tackle CA.
Here is the original image. I used highlight reconstruction in the default inpaint opposed mode, but dropped the clipping threshold to get rid of the purple fringing. lens correction was in the default embedded metadata mode (I’m on the development version, the feature may not be available in 4.2). Other than that, I only have oritentation, exposure (left at default), color calibration and filmic enabled.
Notice that there is no strong blue/purple fringe in the image (unlike in the bottom part of the version you posted in Peek a truck a boo - #13 by eobet):
If I completely disable lens correction (so darktable does not try to fix CA), there is fringing, but still not blue/purple:
It is something introduced later.
There is a huge amount of fringing in the leaves, whether lens correction is on:
But with lens correction on, and chromatic aberrations set, they are both almost completely gone:
Sharpened:
Starting from your image, I used drawn + parametric masks on the blurs module, excluding the darker parts (parametric, on the Jz channel), added 3 shapes to exclude the brightest parts of the car, and refined it all with the details threshold. I then realised that if I wanted to sharpen using diffuse or sharpen, I had to move it above blurs to be able to reuse its mask as a raster mask, used negated, to avoid sharpening the parts we intended to blur.
So, the mask on blurs:
The result and the sidecar:
L1083176.DNG.xmp (50.0 KB)
I know it is, but introducing it via the method @priort used was the only way I could fully get rid of the purple on the leaves… however, now that I’m trying again using your values, you seem to be correct… so that leaves me wondering, my lens correction and chromatic aberration is part of a “style” which I always apply when I start. Now, I usually change the chromatic aberration sliders, but I leave the lens correction untouched. Does that mean that Darktable cached or doesn’t update internal module values for each image a style is applied to, until you start to move sliders? I don’t know what else it could be, because I absolutely did not get this result when I began working on this image.
Thanks again for the tips, I’ll dive into the way you mask next.
EDIT: Turns out I’ll have to wait until the official release of Darktable is updated, because your XMP files did not come in with any masks or lens correction at all (and I’m not adventurous enough to run a nightly build).
This is the parametric part of the mask:
The drawn ones just followed the car’s frame loosely:
And the mask on diffuse or sharpen was the raster mask from blurs, negated:
Thanks! I hadn’t tried the Jz option before.
With the “very large chromatic aberrations” setting, how does the rust on the truck look for you? I think I have to add a mask for it and the window wipers…
Yep. Also, on closer inspection, the masking of the blurs module is pretty bad, too (left: blurs enabled, right: disabled):
I also had changed the white point for this file… these files seem to have an unusual raw wp…its too high for HLR unless you drop the wp or drop the threshold some what… I also use legacy wb which I find less prone to some nuance color casts with some raw files and images… I will have to go back and actually edit the file I never did I just added 2 modules to deal with the branches and never did anything else…
Change the mode in CA to darken only and it will still handle the branches pretty well with Len Corr or Raw CA and the rust is does not lose its character…
