Chromatic aberration
From The Glossary of Digital Photography
Also called color fringing. A type of aberration in a lens in which different wavelengths of light are refracted, or bent, to different degrees as the light passes through the lens. This phenomenon causes color fringing or shadowing in color images and a general fuzziness in black-and-white photographs. There are two forms of chromatic aberration: longitudinal, also called axial; and lateral, also called traverse. Achromatic and apochromatic lenses correct for chromatic aberration. See also achromatic; apochromatic; longitudinal chromatic aberration; lateral chromatic aberration
