An achromatic convergent doublet of two lenses in contact has a power of + 2D. The convex lens has power + 5D. What is the ratio of the dispersive powers of the convergent and divergent lenses?
An achromatic convergent doublet of two lenses in contact has a power of + 2D. The convex lens has power + 5D. What is the ratio of the dispersive powers of the convergent and divergent lenses?