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“Wait…this projector says its brightness is 1,200 lumens - while that smaller projector says its brightness is 3,000 lumens, and is also cheaper? That doesn’t seem right, what information am I missing?”
Customers purchasing their first projector generally seek to acquire the brightest projector within their spending range. However, there are many more important factors to consider when purchasing a projector. Customer end up facing a much 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.
While each of these three methods uses the word "lumens" to describe a given level of brightness - each method measures and defines a "lumen" quite differently. The differences in their definitions cause their values to fluctuate wildly. This can lead to cases wherein a projector using internationally-recognized standards might list a brightness value of 1,000 ANSI lumens, while an equivalent competing model might list their lumens as 2,400, because it uses an LED light sources.
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. |
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.
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 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.
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.
