. "R" . "Reflectance Factor"@en . "http://www.thefreedictionary.com/reflectance+factor"^^ . . "\\(R = \\frac{\\Phi_n}{\\Phi_d}\\), where \\(\\Phi_n\\) is the radiant flux or luminous flux reflected in the directions delimited by a given cone and \\(\\Phi_d\\) is the flux reflected in the same directions by an identically radiated diffuser of reflectance equal to 1."^^ . "Reflectance Factor is the measure of the ability of a surface to reflect light or other electromagnetic radiation, equal to the ratio of the reflected flux to the incident flux." . . . .