The American National Standards Institute (ANSI) standard for lumen is the most commonly used method to evaluate a projector’s brightness. ANSI is a private non-profit organization overseeing standards development for various industries, including projectors. ANSI coordinates standards with standards groups globally.
Lumens are the unit of measurement showing a light source's strength. ANSI standards matter because the facts and figures they approve that measure an ANSI specification establish customer trust and keep unscrupulous players in check regarding the numbers they quote for lumens and other aspects related to the performance of a projector. Before having the ANSI lumen standards, many manufacturers only measured a single element of brightness, like a projector's peak lumen level, which is the initial point that a light source is at its brightest. Unfortunately, a projector’s peak lumens will decrease within minutes of being turned on and is not representative of a projector's real-world brightness. ANSI uses a range of variables to determine a projector's lumens measurement, including light output, beam intensity, distance, and runtime, to name a few.
The ANSI standards-setting processes and procedures are meant to provide openness, balance, transparency, consensus, and due process. ANSI standards are not static; an ANSI member can propose new standards processes. These suggested changes or additions must be presented for public review, comments, and concerns before ANSI will approve its addition to the standards. Once approved, it must be updated or reaffirmed every five years, or ANSI will withdraw its approval.
Consumers should look to see that any projector they are considering purchasing uses ANSI standards to test brightness.