Chromatic Aberration

Chromatic aberration is a consequence of the fact that light of different colours do not focus on the same plane when they go through glass. Think of a simple prism, where white light goes in and a rainbow of colours come out.

Camera lenses are not always good at compensating for this, and the result may be a blue thin line around objects.

To get rid of the line semi-automatically, you can use tools like:

• Adobe Photoshop - Filter > Distort > Lens Correction. Adjust the slides in the box "Chromatic Aberration".
• Adobe Camera Raw - Open the file. (If it is not a raw file, you right-click on it in Bridge and select "Open in Camera Raw..."). Click on Lens Correction. Adjust the slides in the box "Chromatic Aberration".
• Capture NX - In the Edit List, click on "New Step". Select Adjustment > Correct > Color Aberration Control.

You can also manually replace the colour using things like the "Hue and Saturation" adjustment in Photoshop or the Gimp. In Photoshop you can also use Image > Adjustments > Replace Color.

If you do not succeed in getting rid of the chromatic aberration, do not feel bad about it. It is a tricky thing to handle. Good software takes into account the camera and the lens. As an example, Canon's RAW editing software Digital Photo Professional does not make the Chromatic Aberration correction tool available for pictures taken with the Canon EOS D20. Neither does it attempt to correct TIFF or JPEG pictures. This is undoubtedly because Canon knows they cannot make good enough corrections for those pictures.

Wikipedia has a more information on the subject.


The Lens Correction tab in Adobe Camera Raw.


Example of a picture with both green and red chromatic aberration.

Detail showing red aberration on one of the birds.

Detail showing green aberration on another of the birds.