Chromatic Aberration

          Original | Color-fringed
Lateral chromatic aberration on the right

Lateral chromatic aberration (LCA), AKA lateral chromatic displacement (LCD) and “color fringing” is a lens aberration that causes colors to focus at different distances from the image center. It is most visible near corners of images. It is explained in Chromatic aberration.

LCA is measured by SFR, SFRplus, eSFR ISO , SFRreg, and Checkerboard using (mostly) tangential edges near the image boundaries. Dot Pattern uses a grid of dots to make an I3A CPIQ-compliant LCA measurement.

LCA is worst with asymmetrical lenses, including ultrawides, true telephotos and zooms. It is strongly affected by demosaicing. It can be fully corrected in software prior to demosaicing, but only partially corrected afterwards. Picture Window Pro has a fairly effective transformation. In the future, information provided by Imatest (detailed LCA profiles) may improve the degree of correction.