optical density vs photographic density

optical density and photographic density both are nouns.

Word	Noun	Adjective	Verb	Adverb
optical density	Yes	No	No	No
photographic density	Yes	No	No	No

As nouns, optical density and photographic density are synonyms defined as:

optical density and photographic density: (physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation

Other synonyms of optical density include absorbance, transmission density.

optical density (noun)	photographic density (noun)
(physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation	(physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation