The reflecting power of a surface is defined as the ratio of the intensity of the light reflected at perpendicular incidence to the intensity of the incident light. There are two ways of determining the reflecting power of a metallic surface. One is by a direct, or photometric (dioptric) method. The other is by an indirect (katoptric) method.
Proceedings of the Iowa Academy of Science
©1916 Iowa Academy of Science, Inc.
Sieg, L. P.
"On the Variation in the Reflecting Power of Isolated Crystals of Selenium and of Tellurium with a Variation in the Azimuth of the Incident Plane Polarized Light,"
Proceedings of the Iowa Academy of Science, 23(1), 179-186.
Available at: https://scholarworks.uni.edu/pias/vol23/iss1/30