reflection factor vs reflectance

reflection factor and reflectance both are nouns.

Word	Noun	Adjective	Verb	Adverb
reflection factor	Yes	No	No	No
reflectance	Yes	No	No	No

As nouns, reflection factor and reflectance are synonyms defined as:

reflection factor and reflectance: the fraction of radiant energy that is reflected from a surface

Other synonyms of reflection factor include coefficient of reflection, reflectivity.

reflection factor (noun)	reflectance (noun)
the fraction of radiant energy that is reflected from a surface	the fraction of radiant energy that is reflected from a surface