photometry vs measuring

photometry and measuring both are nouns.

Word	Noun	Adjective	Verb	Adverb
photometry	Yes	No	No	No
measuring	Yes	No	No	No

As nouns, measuring is a hypernym of photometry; that is, measuring is a word with a broader meaning than photometry:

photometry: measurement of the properties of light (especially luminous intensity)
measuring: the act or process of assigning numbers to phenomena according to a rule

Other hypernyms of photometry include measure, measurement, mensuration.

photometry (noun)	measuring (noun)
measurement of the properties of light (especially luminous intensity)	the act or process of assigning numbers to phenomena according to a rule