Reflectance
Alternative term: Reflection Factor
The ratio of the reflected luminous flux (Fr) to the incident flux (Fo).
Symbol: ?
Note: Where mixed reflection occurs, the (total) reflectance may be divided into two parts, Specular Reflectance (?r) and Diffuse Reflectance (?d), corresponding respectively to the two modes of reflection referred to in 2-1-135 and 2-1-140.
? = ?r + ?d
Reference: C.I.E. (modified)
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
