Wiktionary
reflectances
n. (plural of reflectance English)
Usage examples of "reflectances".
This solves part of the lightness problem, but not all of it, the absolute reflectances remain unknown.
The small arrows in the panels show how the various reflectances are mapped to their corresponding luminances.
The shaded area within the arrows shows how a typical range of reflectances will be mapped into the corresponding range of luminances.
An observer cannot see the reflectances "directly", but rather requires an atmospheric transfer function to convert reflectances to luminances.