ABSTRACT
A Abbe number Dispersion or separation of neighboring wavelengths by transparent material can be characterized by the Abbe number. If for a given material nD, nF , and nC refer to the refractive indices for the FraunhöferD (589 nm), F (489 nm), and C (656 nm), then the chromatism of the material is characterized by its v-value or constringence
v = nD − 1 nF − nC .
