It’s not the first time we have discussed color defects or chromatic aberration. The color-stripes ruining the photos can embitter our lives, not to mention the viewer’s experience. Photoshop CS2 has a brand new weapon called Lens correction against discoloration, which we have already used in other photo-editing articles. One important feature – decreasing color defect – has not been revealed so far. It’s time to do so.
Load the photo in Photoshop
You can see a 100% zoomed in detail of a photo, taken from one of its corners. Optical color defect or “chromatic aberration” usually appears in the corners. For example, this color stripe over the tree branches purple on one side and green on the other, which could be quite wide in case of a weaker lens.
We’ll use an old friend Filter/Distort/Lens Correction to remove it.
First of all…
Lens Correction window is seen above, where set the appropriate view of the image so that it’s easier for you to work in it.
(1.) Click on the hand icon in the top left icon row (Hand Tool – H key). This will help you stroll over the picture.
(2.) Under the image set zoom to 100%, but you can use a bigger value if you like, this way you will have a clearer view of the color defection. Click inside the photo and with Hand Tool switched on, drag the preview over a problematic area where color defect is clearly visible. In our case it was the area with the branches shown above.
(3.) Our third step will remove the color defect using the control buttons on the right. You’ll find them in Chromatic Aberration section.
Down with color defect
There are two sliders at Chromatic Aberration menu point. Fix Red/Cyan Fringe will fix the red and cyan green shifts, while Fix Blue/Yellow Fringe will take care of the blue and yellow shift in color. The purple/green defect in our photo is closer to the former, so I began with the first slider.
I changed the setting carefully changing 1 increment at a time, and I kept checking the result in the preview on the left. The result was OK at -7. If you use a too high value, the color defect could become even greater.
Since there’s a little blue/yellow strip left after the modification, I changed the second slider a bit too. Here a value of +5 proved to be sufficient.
Where has the rainbow gone?
You can see the result above. We could not remove color defects completely (higher values would have caused new defects), but they have decreased significantly. It’s detectable only in full zoom and only after a close inspection. It’s not conspicuous at all.
If you are interested in alternative methods, see our tips for color defect removal below.