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What is the ANSI, Light Source, and LED Lumens?

How to Convert LED Lumen and Light Source Lumen to ANSI Lumen

2021/03/05

“Wait…this projector says its brightness is 1,200 lumens while that smaller projector says its brightness is 3,000 lumens, and it’s cheaper? That doesn’t seem right, is there something I’m missing?”

A common refrain for consumers looking for their first projector is to make sure they get the brightest projector they can. But when many of these consumers actually look into the issue, they end up facing a bigger puzzle: how to make sense of the various brightness specifications listed on the market. This issue is a result of the fact that some brands on the market choose not to use the internationally-recognized brightness standard adopted by the majority of their peers, ANSI brightness, but instead advertise brightness specs different from others. Of these various brightness specs a consumer might encounter, the most common are: the aforementioned ANSI brightness, LED brightness, and light source brightness.

BenQ projectors use internationally-recognized standards to list a brightness value.

Though the standard unit used for brightness, lumens, is used by all three types of brightness, the differences in their definitions cause their values to fluctuate wildly. This results in instances where a projector, such as a BenQ projector, using internationally-recognized standards, might list a brightness value of 1,000 ANSI lumens, while a competing projector, that actually features an equivalent ANSI lumen value, uses LED lumens instead to list a brightness value of 2,400 lumens. The question then becomes: if all of these types of brightness are measured in lumens, why are their values so drastically different?

Suffice it to say that the reason for this inconsistency is because each of the three types referenced above measures different aspects of a projector’s brightness. For a quick summary of these differences, see the table below:

  ANSI Lumens LED Lumens

Light Source Lumens

 
Origins
ANSI Lumens
Developed and defined by the internationally-recognized association, American National Standards Institute (ANSI).  
LED Lumens
Independently claimed by a small number of brands.

Light Source Lumens

Internationally recognized standard.
 
Purpose
ANSI Lumens
Represent the brightness observed of an image that is projected onto a screen.
LED Lumens
Quantify the brightness sensed by the human eye.

Light Source Lumens

Indicate the brightness observed directly from a light source.
 
Scope of Use
ANSI Lumens
Internationally-recognized standard suitable for all projectors.
LED Lumens
Applicable only to certain LED projectors from a specified number of brands.

Light Source Lumens

Normally used to indicate the brightness of the light source itself, but used by some manufacturers of single-panel LCD. projectors to misrepresent the projector’s overall brightness.
 
Calculation Method
ANSI Lumens
Average out the measured brightness of 9 distinct regions of a projection screen
LED Lumens
Its method of measurement is designed by the companies themselves, which allows them to claim their LED projectors are brighter to the human eye than traditional projectors. Such methods have not been certified by any international organizations.

Light Source Lumens

Directly measure the light source’s brightness.

How to Convert Different Units Back to ANSI Lumens

In general, 1,000 LED lumens converts to 417 ANSI lumens (LED lumen value ÷ 2.4 = ANSI lumens; the conversion rate is based on the manufacture’s publicly disclosed numbers).

1,000 light source lumens converts to 60 ANSI lumens (Light source lumen value x 0.04 to 0.06; the exact conversion rate depends on the efficiency of the projector’s LCD panel for each manufacture).

A quick way to convert the values of one type of brightness to another can be seen below:

Convert LED Lumen to ANSI Lumen

LED Lumen
LED Lumen
120 →
LED Lumen
300 →
LED Lumen
480 →
LED Lumen
1200 →
LED Lumen
2400 →
LED Lumen
2880 →

ANSI Lumen
ANSI Lumen
50
ANSI Lumen
120
ANSI Lumen
200
ANSI Lumen
500
ANSI Lumen
1000
ANSI Lumen
1200

Convert Light Source Lumen to ANSI Lumen

Light Source Lumen
Light Source Lumen
830 →
Light Source Lumen
2000 →
Light Source Lumen
3300 →
Light Source Lumen
8300 →
Light Source Lumen
17000 →
Light Source Lumen
20000 →

ANSI Lumen
ANSI Lumen
50
ANSI Lumen
120 
ANSI Lumen
200
ANSI Lumen
500
ANSI Lumen
1000
ANSI Lumen
1200

*In general, a portion of the brands that use LED brightness publicize an increase over ANSI brightness by a factor of 2.4 for LED brightness, but these numbers are speculations based on the most ideal lighting conditions (such as in a dark room and so on).

**The light source brightness for a normal projector with the best optics and light conversion (the amount of light available after processing by the color wheel, mirrors, and lenses) at most is roughly 16 times the ANSI brightness.

Analyzing the tables, one might notice the one constant between them: ANSI brightness. The reason why this is, is due to how each brightness measure is defined.

ANSI Brightness: The Gold Standard for Measuring Brightness
BenQ projector use internationally-recognized standards ANSI brightness because it is the only brightness measure which uses a standard, scientific methodology that is certified by an international body.

Based on these definitions, the reason why ANSI brightness acts as the standard for measuring brightness (as shown in the tables above) becomes more apparent. This is because ANSI brightness, as indicated in its name, is the only brightness measure which uses a standard, scientific methodology that is certified by an international body. This gives ANSI brightness measures a reliability that is not present in other brightness measures which may rely on arbitrary factors (as in how the HK effect is measured for LED brightness) or present an indirect brightness value (as in how light source brightness omits the negative effects a projector’s internal components has on its end brightness) to produce misleading/inflated numbers.

What is ANSI?

The American National Standards Institute (ANSI) is a private, non-profit organization that administers and coordinates the U.S. voluntary standards and conformity assessment system. Founded in 1918, the Institute works in close collaboration with stakeholders from industry and government to identify and develop standards- and conformance-based solutions to national and global priorities.

What is ANSI Brightness? What is LED Brightness? What is Light Source Brightness?

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