The achromatic lens is a simple solution to reduce chromatic aberration. Its a lens consisting of one group of two or three lens elements. An old landscape lens may consist of such a group, i.e. a biconvex crown glass element and a biconcave flint glass element. Other achromatic lenses use other variants of concave flint glass element and convex crown glass element(s).

Glossary Terms
Community content is available under GFDL unless otherwise noted.