Assertion: lens | /r/AtLocation | contact
Facets:
Source sentences:
text: The simplest case is where lenses are placed in contact: if the lenses of focal lengths f 1 and f 2 are "thin", the combined focal length f of the lenses is given by
text: The simplest case is where lenses are placed in contact: if the lenses of focal lengths f 1 and f 2 are "thin", the combined focal length f of the lenses is given by