Fringeing in Elements

Techniques

18 August 2010 15:25

Fringeing, or Chromatic aberration occurs with some zoom lenses. It happens because the red, green and blue light that makes up a colour image has slightly different wavelengths, and this means the different colours focus at different distances.

Correcting the optics within a lens to account for this is fairly straight forward in fixed focal length (prime) lenses, but it’s more difficult and more expensive to achieve with zooms. As a result, many cheaper zooms suffer from fringeing somewhere along their focal range. By shifting the position of the red, green and blue channels in imaging software, though, it’s possible to realign the focusing and remove – or at least reduce – the effects of fringeing. This is possible in the full version of Photoshop under the Lens Corrections tab in the RAW converter or by using the Lens Correction option under the filter menu, but in Elements you won’t find these choices.

Unfortunately, other than some time consuming cloning work, there’s not a great deal you can do about fringeing in Elements, unless you upgrade to the full version of Photoshop. If the Fringeing is so bad you can’t stand looking at it any more, converting the photograph to mono is a sure-fire way to reduce its impact, though losing all the colour may be a rather drastic solution.

The image attached (above right) clearly shows the Chromatic Aberrations around the outline of the Houses of Parliament. The green/red fringeing can be fixed in Photoshop, inside the Camera RAW interface, but in Elements the job becomes a bit more difficult.