radiography vs picture taking

radiography and picture taking both are nouns.

Word	Noun	Adjective	Verb	Adverb
radiography	Yes	No	No	No
picture taking	Yes	No	No	No

As nouns, picture taking is a hypernym of radiography; that is, picture taking is a word with a broader meaning than radiography:

radiography: photography that uses other kinds of radiation than visible light
picture taking: the act of taking and printing photographs

Other hypernyms of radiography include photography.

radiography (noun)	picture taking (noun)
photography that uses other kinds of radiation than visible light	the act of taking and printing photographs
the process of making a radiograph; producing an image on a radiosensitive surface by radiation other than visible light