Chromatic Aberration - Spot Diagrams

Chromatic Aberration Spot Diagrams...

Refractive lenses scatter light depending on the frequency. This is called Chromatic Aberration or Spectral Dispersion. As light travels through a lens, different frequencies travel through the lens at different speeds. So the total spectrum of light does not come to focus at the same point. Ritchey-Chrétien optic's have only two mirrors. There are no refractive lenses in a Ritchey-Chrétien. So they have zero chromatic aberration and can be used for in-focus imaging across the entire spectrum from Ultra-Violet to Long Wave Infrared (100nm-12mu).

Spot Diagrams from a 16" Catadioptric System showing Chromatic Aberrations caused by the refractive corrector.