# Chromatic aberration

Refractive index of any medium varies with wavelength other than vacuum and the refracting properties of optical system are function of wavelength. Hence, chromatic aberration exist. [1]

## Definition of chromatic aberration:

Chromatic aberration is, “Failure of optic system to bring all colors to a common focus“. The other name for chromatic aberration is color aberration.[2]

If there is no chromatic aberration, then all the rays with different color properties will pass through the center focus.[1]

## Types of chromatic aberration:

### 1) Longitudinal chromatic aberration (axial):

Longitudinal chromatic aberration occurs because of change in focusing distance or back focal length.[1]

### 2) Transverse chromatic aberration (lateral):

Transverse chromatic aberration occurs because of change in magnification.[1]

References:

[1] W T Welford FRS, “Aberrations of optical systems”, Adam hilger imprint by IOP publishing Ltd, ISBN 0852745648, 1991.

[2] James C Wyant, Katherine Creath, “Applied Optics and Optical Engineering”, Academic Press Inc, Vol. XI, pp. 0339, ISBN 012408611X, 1992.