How to remove fringing in Photoshop CC

[Tony M]

Hi there.

I'm having difficulty removing a slight purple fringe in this photo using Photoshop CC and would like some help. The fringing occurs on the border of the sky and the ground/building in the background.

Perhaps I should give some background on the PP of this image. The fringing is a result of using the LAB color mode to adjust the levels of the B channel, in order to recover the blue in the over-exposed sky. (The sun is directly behind the sunflower.) I can upload the image before the LAB processing if it would help. And I can provide the TIFF file of this processed image.



Thanks in advance,

Tony

[dje]

Tony have you tried correcting for Chromatic Aberration under Lens Correction ? You say that the purple fringing was caused by your processing but I wonder if that has just exaggerated the effect of minor CA ?

If that fails, you could clone it out.

Dave

[Tony M]

Hi Dave,

I tried that (at your suggestion) and it didn't have any effect. I think it's due to diffraction, as the original colour seems to be a blend of the colours of the almost-white sky and the horizon (golden brown wheat, green leaves and yellow flowers).

Tony

[Manfred M]

If Dave's suggesting doesn't work, here are a few other thoughts.

Fringing is often the result of aggressive manipulation in post processing and I find that LAB tends to be a touch sensitive (aggressive) when I use it. My guess (looking at the sky in the image) this might be what happening here.

The other root cause of fringing can be sharpening, where the boundaries between darker and lighter areas are enhanced.If you are doing any sharpening in your workflow, you might want to consider doing it after the sky has been corrected.

Ultimately, if none of these techniques work, I suspect Dave is right and cloning it out (which is going to take a bit of time and some decent precision on your part). I would probably try cloning over a number of passes at a high magnification to get a decent blend between the sky and the rest of the image.

[Dave Humphries]

Hi Tony,

(The sun is directly behind the sunflower.)

If we can see this much detail in the sunflower and you were shooting directly in to the sun, the sky must have been vastly over exposed (as you mention) and that will cause all manner of overload issues in pixels adjacent to non-blown areas of the image and these will have a radius of effect greater than sharpening radii typically used.

Given where you are, I think cloning is the answer.

Well that's how I did it when I encountered a similar problem - just wish I could remember where that was, so I could share.

Cheers, Dave

[mrinmoyvk]

Not sure whether it is the proper approach, but I would do clone stamping on the fringing with sky as the source zooming the image to some 200+ %. Opacity would be on trial and error basis.

[dennybeall]

Sometimes "just clone it out" is the best answer. In this case I'd have to agree. Be interesting to know why it occurred but some things are not worth worrying about....

[Black Pearl]

Zoom in to 100-200%
Hit cmd/ctrl + U
Select Magenta and click on the fringe colour you want to remove
Pull the saturation slider down.

If you have just the specific colour selected (fine tune the markers on the colour bar) you can tweak out the fringing.

[Tony M]

Thanks for your suggestions. I decided not to keep this photo, simply because I took better ones the next day in the morning when the sun was in the other direction. This photo is an example. (The composition is different.) The light was easier to work with, but having said that, I did use the selective hue/saturation adjustments of Photoshop to reduce the slight yellow in the leaves, and increase very slightly the yellow hue in the flowers. The result is a cleaner-looking image.

[Manfred M]

Is it a better photo? I'd say the general image is better, but the sunflower itself is not.

In my experience, flower images work best when they are back-lit as the light transmitted through them is far more interesting than when they are front-lit. As you have already determined, there is a risk of a blown out sky and other undesirable issues.

Take a look at your first post, and while the flower itself is far from perfect, you can see what the transmitted light does for the petals; nice light and dark areas. On the other hand, while you have a very nice looking sunflower in the second post, I would suggest it does not have as much potential as the first image.

[Tony M]

I take your point; however, I don't particularly like the flower because it's tired-looking. I should have chosen a better subject. The truth is, I was with other people when I took the first photo and didn't take the time to select a good subject. On my next visit (next season) I'll try to do better

Thanks very much for your comments.

Tony

[DanK]

Tony,

I know this thread has moved off the original question, but in case the newer topic of lighting for flowers is interesting to you, let me add my two cents.

I think Manfred's comment is a specific version of a more general one. I do a lot of flower photography, and I do often use backlighting. It adds variations in color, shows up texture, and in general can create a more interesting image. However, lots of different types of lighting create interesting effects. To pick one example, side lighting is very good for highlighting some textures, and the shadows it creates, if not too severe, can add interest. I'll post a few examples. The more general version of Manfred's comment that I would offer is that direct frontal lighting is often not very interesting (there are exceptions, of course), particularly when it is harsh full sunlight.
Dan

Two flower shots with side lighting (but not only side lighting);