(n) :
(optics) A lens generally composed of two separate lenses, one convex and one concave and generally of different materials, in such a way that the chromatic aberration produced by one is corrected by the other.
(n) :
(optics) A lens generally composed of two separate lenses, one convex and one concave and generally of different materials, in such a way that the chromatic aberration produced by one is corrected by the other.