Telescopes

Apochromats with three lens elements are also often referred to as triplet apochromats. Only this telescope design can sufficiently correct unwanted chromatic aberration. The secondary spectrum, the residual chromatic aberration, is corrected by different types of glass and refractive indices. The three-lens ED apochromats reduce chromatic aberration almost completely. The image is not only clear and neutral, but also has particularly high contrast.