Music video by Justin Bieber performing Never Let You Go. (C) 2010 The Island Def Jam Music Group. #VEVOCertified on November 9, 2010. http://www.youtube.com/vevocertified.
Lumens are a unit of measurement of the total brightness that comes from a light source, in this case, a projector. One may also see the term ANSI Lumens. ANSI is an acronym for the American National Standards Institute. In general, the more lumens a projector has, the brighter the image on the screen.
Definition of 'overhead projector'. overhead projector. An overhead projector is a machine that has a light inside it and makes the writing or pictures on a sheet of plastic appear on a screen or wall. The abbreviation OHP is also used. COBUILD Advanced English Dictionary.