I developed the original DNG-File without any modification other than resizing into the attached jpg. Reducing the heavy purple fringing along the window frames on the left hand side with function “Defringe” was barely successful. I even tried to create a color mask in Local editing and reduced the saturation. But I noticed then there are more purple areas on the wall which were desaturated as well. In this case a color mask seems not to be a good idea.
Anyone with a good idea to tame the purple fringing?
I think this question belongs in the Processing category.
@01McAc The metadata of the image shows this is shot on a Leica M10 with a Voigtlander VM Nokton 35 mm 1.2 ASPH. From what I see by browsing some online lens reviews, this explains the softness I see around the center and in the corners. The fringing also seems to be quite heavy in this lens in general: Review: Voigtlander VM 35mm 1.2 III - phillipreeve.net Additionally you have a difficult shot with blown highlights. I think that expecting a nice defringing seems a bit of a stretch…
If you are able to share a raw file with permissible CC license, others might be able to provide some tips and tricks.
Hi,
a combination of masks and defringe works reasonably well for my taste (you might disagree of course):
The processing parameters are embedded in the image metadata
It is not only reasonably well. It is excellent, thanks.
How can I apply the embedded processing parameters to the image? Haven’t done it before.
Cheers, agriggio. A smart approach which I wouldn’t have used in my lifetime. So far I have never used a parametric mask. In combination with the brush mask it seems to me like an exclude functionality. I see- I am constantly learning about ART and RT.
Well noticed and investigated. The CV Nokton 35 mm 1.2 ASPH. (version II) is imho a very good lens and highly underrated in the M-universe. Probably too cheap… 
I have never had any issues with purple fringing with this lens until this attached photo. I went nuts when I didn’t get rid of the fringing. agriggo’s approach is quite smart and new for me.
Here is a quick shot at it with RawTherapee Dev. Combination of Local Adjustments > Color & Light and Defringe.
L1000282-1.jpg.out.pp3 (24.5 KB)
Sorry, I had an itchy trigger (mouse) finger. I couldn’t resist finishing the edit.
L1000282-2.jpg.out.pp3 (26.5 KB)
Thanks for your expert opinion, but I wasn’t asking for any thoughts on this lens. The lighting condition in the premise were very special. I guess you’ll have much better lenses. ymmv
is the emoji you were looking for ! 
New for 2021 - Topaz Graffiti Defringe… 