Lux vs Lumens Projector

Do you feel lost when you hear people discussing projector specifications and saying things like- “This projector has 3500 lumens brightness”? What are lumens? How does it matter?

A projector comes with several features that affect the quality of the picture being projected. One of the most important features is the brightness of your projector. Both lux and lumens are S.I. units that indicate the level of brightness produced by the projector.

We’ll help you understand these terms better in this article, along with how these affect your projector’s performance and what value you require.

Lux vs Lumens

Lux and Lumens are both units of luminous flux. To understand luminous flux, you need to understanda few terms beforehand.

Our electromagnetic spectrum consists of Radio waves, Microwaves, Visible Light, X-rays, and many more which come in different wavelengths and frequencies.

  • Radiant Flux: The measurement of the electromagnetic energy of certain wavelengths on the electromagnetic spectrum is radiant flux.
  • Luminous Intensity: The measure of the power emitted by a light source in one particular direction is Luminous Intensity. It’s measured in Candelas (Cd).
  • Luminous Flux: Luminous flux is the radiant flux only for visible light, which is the only wave that can be seen with the naked eye.

Now that you know the basic terms, it’ll be easier to understand what Lumens actually measure.

1 Lumen is the luminous flux emitted by a light source of 1 Candela of intensity over a solid unit angle in one second.

Other than projectors, lumens are used to measure the brightness of other light-producing objects, like lamps, and their values don’t change.

As you can understand, a high value of lumens means the luminous flux or light energy of a source is also high. And, the greater the light energy, the brighter will be the light.

On the other hand, lux is the measure of illuminance. That means it’s a measure of luminous flux per unit area.

Therefore, 1 lux measures how much lumens of light strikes a surface of 1 square meter. With the help of lux measurements, you can get an indication of the brightness of the projector at different distances from the screen.

When you take the projector further away from the screen, the size of the screen increases. Since lumens are fixed values, lux decreases with increasing distance from the screen.

To finish it off, none of these measurements are necessarily better than oneanother, rather they’re just used for slightly different purposes.

Lumens and ANSI-Lumens

If you’ve checked out at least 5 projectors, you have surely met the term ANSI-Lumens.

You already know that Lumens is the measure of luminous flux produced by a source. And, the greater the lumens, the brighter the light.

ANSI-Lumens indicate the same properties, but they’re more accurate and reliable.

ANSI stands for American National Standards Institute and it uses various methods to perfectly determine the value of lumens for the projectors.

One of the methods they use for precise measurements is using a 100% white image of uniform squares. Light is shone on the image only from the projector. No other light-reflective surfaces are kept in the room.

Lux is measured using an Illuminance Meter, which is positioned in front of the projector and the readings are taken. The ANSI lumens rating is calculated by taking the average of all the lux values and then multiplying by the area of the square.

Many projectors may come with incorrect lumen values, as they might not have been tested properly.

You must check out the ANSI-Lumens value of the projector, if available since they’re much more authentic. Moreover, if you aren’t 100% sure, it’s safer not to go for projectors with no ANSI-Lumen ratings.

How Bright Should Your Projector Be

The lumens ratings or brightness you should go for depends on the purpose you’ll be using your projector for, along with the lighting conditions and resolution of the pictures.

Projectors can be used for endless purposes. Let’s take a look at the recommended lumen values for some of them.

  • Presentations: If you’re mainly getting a projector for business presentations and meetings, projectors with more than 1000 lumens are good enough.
  • Gaming: If gaming is your main focus, you should go for 2500 lumens projectors. Games have various types of textures and beautiful graphics, which will look dull on projectors with lesser lumen ratings.
  • Movies and TV Shows: If you watch TV shows and movies, or want to turn your room into a home theatre, projectors with lumen ratings above 2000 are recommended for the perfect experience.

Lighting conditions play a major part in which lumen value you should opt for.

  • If you’ll be using your projector in dim-lit conditions, the brightness ratings mentioned above are good enough for you.
    You can go for lower lumen ratings if you’ll be operating in total darkness.
  • If you’ll be using the projector where it’ll be fairly bright and lighted up, you should check out projectors with lumen ratings above 2500.
    Whatever purpose you’ll use it for, lighted conditions will make the projector screen look dull and faded, so projectors with greater lumens are a must.

If you want to watch 4K and 8K movies or play high-resolution games often, it’s a smarter move to purchase projectors with higher lumen values than recommended.
Higher resolutions produce pictures of greater quality, with enhanced sharpness and details, and better colors.
But, you can’t enjoy any of that if your projector has a low brightness rating and the effect of the 4K resolution won’t really stand out.


As you’ve seen, lux and lumens are both useful for determining the brightness levels of a projector. Even though lumens are the more widely-used unit, lux helps to get a better understanding for different screen sizes.

It’s important for you to know about both the units, along with the more authentic ANSI-Lumen unit.

From now on, you won’t be confused when people talk about projector specifications anymore, but more importantly, you know exactly the lumen rating you want in your projector.

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