Assertion: telephoto lens's length | /r/HasProperty | necessary
Facets:
Source sentences:
text: The second shot was taken at 40mm, and this shorter focal length was necessary because I was much closer to those boulders in the foreground.
text: Although many war photos have been shot with 35mm or 50mm primes, sometimes longer focal lengths are necessity.
text: This focal length is necessary as you cannot usually get close enough to the action to get good shots otherwise.