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Chromatic Aberrations.


C

Captain Chickenpants

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Does anyone have a good technique for getting rid of these?
I tooks some photos at the weekend which have quite visible chromatic aberration.

Cheers.

CC
 
There are a lot of plug-ins out there, dedicated to correcting severe distortions and this is just one of them... http://www.kekus.com/plugin/ I've never used any 3rd party plug-ins myself so I can't recommend any in particular. Perhaps there are those here who can! :)

If the distortions are minor, I would try a number of different PS native filters (depending on the type of distortion) including and not limited to any of the Distort filters as well as transform->distort.

Perhaps if you post up an example of the type of distortion that you are refering to Captain Chickenpants, somebody here could be of more help! ;)
 
I have cropped and slightly downscaled one of the photos trying to get the problem in view.
Basically it is a common problem on digital cameras, at high contrast edges you get purple/blueish fringes.
The cause is to do with the fact that the camera lens focuses different wavelenghts of light slightly differently, such that red light is focused slightly behind the sensor and blue slightly in front (it might be the other way around),
, combine this with blooming (an overexposed pixel bleeding into a neighbouring one) and you can get some quite ugly fringes. The one in the top right corner is especially bad. But their is a bluey tinge to the whole cliff edge.

There are quite a few tutorials about which basically tell you to select the purples color range and then desaturate it. I feel there must be a more exact method available, especially when it appears that the green channel is completly unaffected (as you would expect as the image is focused exactly right for green wavelenghts of light).

I had ago at selecting the sky, expanding the selection and then subtracting the original sky selection from this to select just the sky boundaries, but the problem is that some aberration is in the sky, and some is outside the sky.

A good link and explanation,. along with one method of removing it.
http://www.dpreview.com/learn/Glossary/Optical/Chromatic_Aberrations_01.htm

CC
 
;) Ahhhhh... thanks for the explanation and the link CC! :)

Oddly enough, I own an Olympus C3030Z and I have never experienced this problem, to the degree that you have exampled. [confused] Fingers crossed...obviously I've been lucky thus far!

I'm going to download your image and have a go at it. I'm sure that others will do so and maybe we can all learn something together! ;)
 
I am using the C2020 Zoom (getting on a bit now, but I love it!).
You generally will only get the problem with very sharp changes in brightness, and (i believe) only on vertical edges.

The attached image shows what I mean about the different color fringes on different edges. You can clearly see light to dark transitions cause a red frind, dark to light transitions cause a blue fringe.

The picture is of me climbing :-)
 
:\ It's not perfect, but it's a vast improvement and very quick to do... using Select->Color Range and then desaturating the selection.

[stuned] B7 Looks like fun, your rock climbing hobby, CC!!!! :righton:
 
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