photographic density vs transmission density

photographic density and transmission density both are nouns.

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

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

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

Other synonyms of photographic density include absorbance, optical density.

photographic density (noun)	transmission 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