What is an Aberration?

An aberration is when an optical system deviates from the expected ideal outcome. For example, lenses are expected to focus all rays of light to a single focal point. In practice, no lenses accomplish this. The cause of the deviation is called an aberration. In general, optical aberrations are divided into two classes: chromatic aberrations and monochromatic aberrations. Depending on the class, the aberrations can be corrected by e.g. inserting additional optics or replacing lenses with curved mirrors. The StellarNet BLACK-Comet concave grating spectrometers offer research-grade performance by reducing aberration and improving optical performance.