Removing chromatic aberration from photos in photoshop
Ever had photos (useually shot against bright background light, cromed surfaces is always realy bad) show ugly purple, blue or yellow edges? That’s called chromatic aberration and is a problem with cheaper lenses, but even expensive L type lenses can bite you with chromatic aberration if you are unlucky.
You can deal with chromatic aberration in Camera RAW, but the best way is to deal with it inside photoshop where we have a much more powerfull environment to help us.
Chromatic aberration is caused by channels not aligning properly at places in the image. We can fix this by using the lens correction filter.
First convert your image to a smart object from the filters menu, and then select the Lens Correction filter from the filters/Distort submenu. When the filter dialog is open, turn of the grid by unchecking the tickbox in the lower part of the dialog as we don’t need it, it’s used to fix things like barrel distortion or pincusion distortion.
What we are interested in here is the Chromatic Aberration sliders labelled Fix Red/Cyan and Fix Blue/Yellow fringe. Adjust the sliders according to the color of chromatic aberration you have in the image. Watch other parts of the image as you adjust as fixing Red/Cyan may bring out Blue/Yellow fringe. You probably will not be able to fix everything, but don’t worry, the best is yet to come.
Done? Good, OK out of the lens correction dialog.
Any chromatic aberration left in the image is useually just color noise so lets fix that. From the filters/Noise menu select Median.
Whoa this can’t be good, it’s blurred my image so it looks like ass? Yes, that’s what we want. Adjust the amount slider so the chromatic aberrations you have left is blurred nicely, somewhere around 10-20 should do. Ok out of the median dialog box.
Right now we are applying the median filter to both color and luminance and that blurs the whole image like applying gausian blur or something.
Locate your median smart filter layer, see that little icon that looks like a couple sliders right beside the filter layer?
Doubleclick that and bring up the blending modes for the median smart filter.
Ready? Set the blending mode to Color and watch the remaining chromatic aberration being wiped out like magic.
By the way If you are A/B’ing your changes and get an annoying progress bar taking forever each time you turn a smart filter on/off, just turn it off once, then use undo/redo (Control+z) instead and A/B’ing will be instant.
