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.
The definition of a lumen is a measure of the total amount of visible light emitted by a source. It is a pretty complex equation to find out exactly how many lumens a flashlight is. Mathematics aside, the best way to think of lumens is to compare them to birthday candles. If you have 1 candle 1 foot away from your face, it emits the same amount of light as 1 lumen.