Chromatic aberration

Not to be confused with Chromosome aberration.
Focal length of lens varies with the color of light
Photographic example showing a high quality lens (top) compared to a lower quality one exhibiting transverse chromatic aberration (seen as a blur and a rainbow edge in areas of contrast)

In optics, chromatic aberration (CA), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point.[1][2] It is caused by dispersion: the refractive index of the lens elements varies with the wavelength of light. The refractive index of most transparent materials decreases with increasing wavelength.[3] Since the focal length of a lens depends on the refractive index, this variation in refractive index affects focusing.[4] Since the focal length of the lens varies with the color of the light different colors of light are brought to focus at different distances from the lens or with different levels of magnification. Chromatic aberration manifests itself as "fringes" of color along boundaries that separate dark and bright parts of the image.

  1. ^ Marimont, D. H.; Wandell, B. A. (1994). "Matching color images: The effects of axial chromatic aberration" (PDF). Journal of the Optical Society of America A. 11 (12): 3113. Bibcode:1994JOSAA..11.3113M. doi:10.1364/JOSAA.11.003113. Archived from the original (PDF) on 2016-03-05. Retrieved 2015-08-28.
  2. ^ "Secondary spectrum and spherochromatism". telescope-optics.net. Retrieved 2024-06-06.
  3. ^ Thibos, L. N.; Bradley, A; Still, D. L.; Zhang, X; Howarth, P. A. (1990). "Theory and measurement of ocular chromatic aberration". Vision Research. 30 (1): 33–49. doi:10.1016/0042-6989(90)90126-6. PMID 2321365. S2CID 11345463.
  4. ^ Kruger, P. B.; Mathews, S; Aggarwala, K. R.; Sanchez, N (1993). "Chromatic aberration and ocular focus: Fincham revisited". Vision Research. 33 (10): 1397–411. doi:10.1016/0042-6989(93)90046-Y. PMID 8333161. S2CID 32381745.