Removing Chromatic Aberration
Magenta or green fringing
Chromatic aberration, the term we apply to the nasty magenta or green fringing in digital photography. The areas most affected are high contrast areas, for example around trees the high contrast of the sky. It will ruin a good photo. But fear not, we have a technique that will help target those areas and fix them.
Here is a classic example of chromatic aberration, not a great photo, but a good example nonetheless.
Image 1 shows high contrast areas around the bridge. The sky has ended up quite over-exposed and there is magenta fringing where the tones change so dramatically.
Image 2 clearly shows the issue. Correcting our photo of this problem is, fortunately, easier than expected.
Copy your layer
Open the image in Photoshop and copy the layer. Drag the layer to the new layer icon as shown in image 3.
Blur the layer
Next we are going to apply a blur to the top layer. Select the top layer and click on Filter in the menu and select Blur/Gaussian blur. See image 4.
You need to be quite generous with the blur, in this case I have chosen a blur setting of 50pixels.
Click OK to apply the blur and then we need to take a look at the blending mode of the layer.
Change the blending mode to Colour. When you change the blending mode you will notice although the magenta fringing has gone, we have also lost colour across the entire image. Not good! But do not fear…
We are going to add a vector mask as shown in image 7. click on the add layer mask icon. You will add a white mask to the layer. We need to change this to a black mask – we need to inverse it. Ctrl+i(win) cmd+i(mac) If you can remember to hold down the alt key when you click the add vector mask option then you will get a black mask! The image will now revert to it’s original state. In other words, the mask now has a big hole in it so we can see the image underneath.
Now select a soft round paint brush and choose white as the colour. Resize your brush just a little larger than the magenta fringing and spray over all the magenta areas.