Lateral chromatic aberration
From The Glossary of Digital Photography
One of two types of chromatic aberration found in lenses that are often seen as purple fringing. The other type is longitudinal chromatic aberration. The purple fringing—found especially in the super-wide-angle lenses used in digital photography to make up for their magnification factor—is caused by different wavelengths of light rays focusing at different points in the image. The lateral chromatic aberration usually increases with the distance from the center of the image and is more pronounced at the edge of the image. One of the differences between lateral and longitudinal chromatic aberration is that the former has two colors on each side of an object, while the latter has only one color that surrounds the object. Some corrections can be made in Photoshop and in specialized image-enhancement programs. See also chromatic aberration; longitudinal chromatic aberration
