Talk:Ansi lumen

Potential article text
An ANSI lumen in a particular unit of measurement for the light output of a projector. A lumen (lm) is a unit for measuring luminous flux, or the perceived output of a light source. ANSI is an acronym for the American National Standards Institute. As such, an ANSI lumen is a lumen measured in the specific method defined by the American National Standards Institute.

History In 1992, ANSI defined a method for measuring the lumen output of projectors (both film and video). The method involves adjustments of brightness and contrast, measurements of a white field at nine designated spots on the screen, and the averaging of the measurements multiplied by the screen area.

Function The ANSI method for measuring lumens is very accurate and is therefore used in the marketing of projectors. Manufacturers almost always list the ANSI lumen output of their projectors as a point of comparison.

Math The lumen is defined as 1 lm = 1 cd·sr = 1 lx·m2 ("cd" is candela, "sr" is steradian, "lx" is lux and "m" is meter).

Misconceptions In the marketing of home theater projectors, ANSI lumens can be somewhat misleading. The ANSI lumen measurement represents the optimum potential of the projector and does not reflect variables such as screen size, screen material, ambient light and viewer eye fatigue. Some projectors feature video optimization technology which can skew the ANSI lumen rating.

— Preceding unsigned comment added by Rasvanjan (talk • contribs) 01:01, 7 December 2010


 * This is not an article, it is a talk page. I don't think creating a separate article on ANSI lumens is a good idea. They are not really a distinct unit, but rather a prescribed standard for how to measure lumen output of projectors. As such, they are best covered in the article on lumens.--Srleffler (talk) 05:17, 8 December 2010 (UTC)