I am trying to process this picture, which I like very much, but the chromatic aberration along her arms is just too much for me.
The CA correction in RT’s “raw” tab has no effect. In the CA correction in the “Transform” tab, I can change the color of the CA, but not make it disappear.
I put the photo into gimp, used free-select around the edges of her arms, and then used the hue-saturation tool to desaturate magenta. That was so-so but still looked weird.
RT has tools such defringe and false color suppression, and less conventional tools that might tackle the problem. Also try changing the demosaicing method.
Thanks. Those are a bunch of tools that I never used before, aside from demosaicing method, but I have only changed that in the past to work on very noisy pictures.
The defringe tool had the best effect.
False color suppression didn’t really do anything for me.
Changing demosaicing helped also. The purple fringes were entirely gone using the “mono” (B&W) method! But if I wanted to keep it in color, VNG seemed to be the only one with an effect, and it was subtle.
It’s funny to me that none of the tools with “Chromatic Aberration” in the name had much of any effect, but defringe did. There is still a line around her arms, but you have to be pixel-peeping pretty close to notice it. There was also some green fringing by the windows behind her, which defringe helped with a bit once I adjusted the equalizer.
It needs to play with light as it needed some exposure lowering, and there’s yet some fringing on the fingertips, but the gray border is less evident now.
Thanks! You did manage to mitigate the fringing a bit better than I. Thanks for the PP3 file for me to examine. And yeah, I know what you mean. I run into fringing problems with that lens quite often. For that reason, and some autofocus weirdness, I’m thinking about selling it and getting a different portrait lens.
I do have another shot, almost the same as this one, but one stop less exposure via closing the aperture. I’ll mess with that one, though I do sort of like the overexposed “high key” sort of look with this one.
If you want to study my pp3, I advice you to take a closer look at «False color suppression steps» (yes, it has an impact, too) and «Highlight reconstruction Method» (this one has to be seen at 400-500%).
And while you’re at the Exposure tool, turn on the «Clipped highlight indication» and lower the exposure slowly. You will see that around the fringing there’s a second invisible fringe made of clipped highlights, and that it affects the purple fringing. That’s why lowering exposure is important in this image.
And given that in such composition there’s no place for any fringing at all, you will have to live with the artifacts introduced by such aggressive developing.
CA is a very common problem with almost all 85 mm portrait lenses in this kind lighting situations. You cannot really get rid of it. I am shooting a lot Nikon 85/1.8 G which has very similar problems, which are of course annoying, but almost always manageable. Just identify color to correct in defringe and set radius and strength. Usually gone after that.
85/1.8 lenses have tremendous value. Some lenses with lesser CA issues are:
EF 85/1.4 IS can be somewhat better, but is very expensive.
Sigma 85/1.4 Art is also better, but heavy and may have AF issues.
Tamron 85/1.8 VC is a step up and has VC, but in other respects does not yield more interesting photos
Usually 135 mm lenses have much better CA correction, but they are not “85s”.
Photo seems to have some camera shake. 1/125 s is rather slow real life shutter speed in 85 mm portraiture when stabilization is not available. I don’t have good hands and seldom go below 1/160 s.
But if I wanted to keep it in color, VNG seemed to be the only one with an effect, and it was subtle.
