Assertion: telephoto lens's length | /r/HasProperty | efl
Facets:
Source sentences:
text: To take this one step further, it is best to consider the “effective focal length” (EFL) of the lens by taking the crop factor of your sensor into account.
text: A zoom lens is a mechanical assembly of lens elements for which the focal length (and thus angle of view) can be varied, as opposed to a fixed focal length (FFL) lens (see prime lens).