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Lux Vs. Lumens in Projectors: All You Need To Know


Understanding the specifications of projectors is an excellent way to ensure that you know what you’re getting. Knowing what you’re paying for is critical now that the projector market is flooded with options that vary widely in quality and features.

Lux and lumens are terms that are thrown around a lot in stores and on guides online. While it’s not difficult to grasp that the terms help measure brightness, what do they really mean?

Also, is one term better than the other? How many lux or lumen should your projector have?

We’ll help you with these questions and compare lux vs. lumens projectors for you in this post.

Which Is Better: Lumens Or Lux?

Lux and lumens are SI units that are used by projector manufacturers to measure their product’s brightness.

To understand lumens, you must understand luminous flux. Luminous flux is the total amount of light that a source produces in unit time. 

Confusing luminous flux with radiant flux is easy if you’ve read about them before. Luminous flux is only used to measure the electromagnetic waves that are visible to human eyes. On the other hand, radiant flux measures the EM waves from all sources.

A more in-depth, more scientific explanation of lumens is that it is the measure of the number of packets of light (or “quanta”) a source of light produces. One lumen is the luminous flux that a one-candela source of light generates over a one-steradian angle.

The unit lux is very different from lumens – it is a measure of the brightness in terms of surface area. In projectors, you’ll find lux represented as lumen per square meter.

Lux takes into account how much an incident light illuminates a surface, giving a measure of how the eyes perceive the intensity of light. The spread of light, or more accurately, the area’s effect on luminous flux, is considered.

It’s not hard to see how the two units of measurement are similar. Both measure the illuminance (or, in layman’s terms, the brightness) of light, but in different contexts.

They are just different
They are just different

To sum up:

Lumen is a measure of the amount of light that a light source emits and takes the sensitivity of the human eye into account.

Lux is a measure of the brightness of a light emitted by a source after considering its spread over an area.

Now that you understand what the terms mean, you will also realize that they represent different qualities of a projector. The number of lumens of a projector remains constant, whereas the lux changes with distance. The further away the projector is from the screen, the larger the picture and the lesser the lux will be.

Therefore, one measure is not inherently better than the other. They just describe different things.

ANSI Lumens

ANSI term

Before you go ahead and buy any projector, there’ll be several features and specifications you’ll need to compare and evaluate. The most misunderstood of which is the lumen quality. 

You now understand that the lumen measure of a projector is crucial to look at since it plays a huge role in the quality of the image produced by the projector.

One of the things that many people get confused by is ANSI lumens. Some manufacturers list ANSI lumens, and it is essential for you to note that it is different from regular lumens.

ANSI lumens are much more accurate than regular lumens because the methods used to calculate ANSI lumens involve more variables.

Even five years ago, some projectors would come with inaccurate lumen values mentioned. But most modern projectors come with ANSI lumen values mentioned since the unit is much more quantifiable.

With the ANSI lumen reading handy, you’ll be able to understand the power of a particular projector more reliably.

How Many Lux Should A Projector Have?

Different kinds of content require different amounts of brightness to look its best. Besides considering the kind of content you watch, you must also consider how bright your room is and the projector’s resolution.

Cumulatively assessing these three factors should give you a good idea of how many lumens you need your projector to have. Since the measure of lux is variable with distance, it is not the right unit to base your buying decision on.

If you’re looking to get a business projector, you don’t need a very powerful projector. However, if you want a projector for your home theatre, it must be exceptionally bright.

Here’s a quick guide to the number of lumens you should be looking for depending on the purpose of the projector:

Your home theatre projectors need to be brighter
Your home theatre projectors need to be brighter

Throw ratio, contrast, and other specifications also affect the perceived brightness of a projector’s output. Considering that, it is best to buy the brightest projector you can afford.

Home theatre projectors most commonly have a resolution of 4K and 1080p. Projectors that are geared for gaming typically have a 1080p resolution, and portable projectors have a comparatively lower resolution of 840 x 480. 

Business and portable projectors are only useful for displaying text-based presentations.

Keeping in mind the ambient lighting of your projector room is also important. If you have a bright room, you must get the most powerful projector you can afford since the light in the room affects the brightness of the projector’s output directly.

It is also essential to understand that the larger the screen size, the lesser the projector’s brightness. Make sure your projector is bright enough for excellent large-screen viewing if you prefer it.

To Conclude

Now that you understand the difference between the terms, you know that comparing lux vs. lumen projectors doesn’t make sense.

While the two terms relate to each other, there’s a massive difference in how they measure the brightness of a projector screen.

When picking a projector, checking the lumens it can generate is the only accurate way to determine how bright it is.


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