TECHSPEC® VIS-EXT Coated Double-Concave (DCV) Lenses are designed to have two inward curved surfaces and a negative focal length similar to Plano-Concave (PCV) lenses. These lenses can be used for balancing aberrations created by other lenses within a system due to their negative spherical aberration. Plano-Concave (DCV) lenses are commonly used in a variety of applications including image reduction, beam expansion and telescopes. TECHSPEC® VIS-EXT Coated Plano-Concave (DCV) Lenses offer optimal performance in the 350nm to 700nm range. These lenses are also available Uncoated, MgF2, VIS 0°, VIS-NIR, NIR I, or with NIR II AR coating options.