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.
A lumen is the amount of light a certain lamp gives off. If replacing a standard 150 Watt light bulb which gives off around 2600 Lumens, using a 42 Watt CFL or a 25 Watt LED is about the equivalent.