Projector Lumens - ANSI vs Laser/LED vs Marketing

What are ANSI Lumens?

An ANSI lumen is a standardised measure of brightness established by the American National Standards Institute.
To measure a projector’s brightness according to the ANSI standard, a strict method needs to be followed, with controlled room conditions (e.g. ambient temperature, amount of refracted and reflected light, screen surface etc.). Once the projector brightness and contrast levels are adjusted according to a set of rules and the testing conditions are stable, a full white screen is projected and brightness readings are taken from a given distance at 9 points across the screen using a 2° or less Light Meter.

What are LED Lumens and Laser Lumens?

An LED Lumen or Laser Lumen is a measure of brightness quoted by some manufacturers taking into account the HK (Helmholtz-Kohlrausch) effect.

The Helmholtz-Kohlrausch effect is a phenomenon which makes the human eye perceive images with a higher colour saturation as brighter than they really are. Highly saturated colours appear brighter than less saturated colours or even white light of the same luminance.

The latest generation of LED projectors and Laser projectors features a wide colour gamut with greater colour saturation so the images they project look brighter to the human eye than the same images from standard lamp-based projectors of the same ANSI lumens brightness.

Some manufacturers therefore choose to quote the LED lumens or Laser lumens alongside the ANSI lumens to indicate the added perceived brightness that results from the HK effect and improved colours of solid-state light sources.
The brightness of a projector in LED or Laser lumens is always higher than its ANSI lumens brightness. Typically, the LED lumens value is between 1.3x to 2.4x higher than the ANSI lumens value based on manufacturers’ measurements and comparisons with equivalent lamp-based projectors.

LED or Laser brightness is a useful measurement to look at when choosing a projector to get an indication of how bright the image may look like. However, because quantifying the HK effect is subjective and there is a fairly big difference between 1.3x and 2.4x the ANSI lumens value, LED lumens and Laser lumens shouldn’t be given as much weight as ANSI lumens when comparing projector models.

What are Light Source Lumens?

As the name indicates, Light Source Lumens is the measurement of light output directly from the projector’s light source (LED, Laser or lamp), before the light has been processed through the projector components to create an image that is then projected.

Light Source Lumens are always significantly higher than ANSI Lumens as the light has not been processed through components such as the colour wheel on DLP projectors or even different quality lenses which cause a loss of brightness.
Depending on how efficient the projector components are, an ANSI lumen is equivalent to 0.04x to 0.06x a Light Source lumen so 1000 Light Source lumens would be only 60 ANSI lumens.

Reputable projector manufacturers do not quote Light Source lumens on projector specifications.

What are Marketing or Fake Lumens?

Marketing lumens is used to refer to projector brightness values used by unscrupulous manufacturers often found on marketplace websites such as Amazon, Ebay etc.
These manufacturers quote values which are greatly exaggerated and nowhere near the ANSI lumens measurements in order to lure unsuspecting customers.

Brightness levels which are not clearly labelled as ANSI lumens, or quoted alongside the ANSI lumen equivalent by the manufacturer as in the case of LED and Laser lumens, should be taken with a large pinch of salt.