While it would be lovely if we could turn up to a retail store or click a link online and buy a projector, there are a few considerations that need to be taken into account before you hand over your cash – namely brightness.
In the past few years, there’s been a split in opinion over the way in which projector brightness is calculated. There are some brands who feel others are claiming levels of brightness higher than what they are able to achieve to grab customers’ attention – after all, higher numbers must mean it’s better, right?
That’s not always the case. And in the context of brightness, it comes down to deciding between lumens and ANSI lumens. What do they mean, what’s the difference, and which calculation should you ultimately rely on when looking for the best projector?
We’ll explain what you need to know.
What are lumens?
As defined by the International System of Units, a lumen is a measure of light produced by a device that’s visible to the human eye.
Lumens is not to be confused with nits, the term used to measure brightness from emissive (i.e. radiate from) displays.
However, while lumens measure the amount of light produced by a device, you aren’t staring at the projector but at the screen it’s beaming on. What’s actually the most important is how big the screen/image is.
So while knowing how many lumens a projector can produce is helpful, it doesn’t provide the full picture of how bright the overall image will be. If you are beaming at a screen, it’s also important to know how much that screen can emit in terms of nits to give you a better idea of the overall brightness.
What are ANSI lumens?
ANSI lumens, as defined by the American National Standards Institute (ANSI), is a measurement of the overall amount of light outputted by a projector’s light source. The higher the lumen value, the brighter the projector.
Based on that description, you would assume that both lumens and ANSI lumens cover the same principle. Not quite.
ANSI lumens does not refer to the amount of light visible to the human eye but the overall brightness. To calculate ANSI lumens, it goes through a different testing process that assesses more variables than the more ‘standard’ lumens.
While ANSI lumens’ calculations are more complicated, they are considered to be more accurate than lumens. ANSI lumens is accepted as the most common way of determining the brightness of a projector.
How are ANSI lumens measured?
ANSI lumens is considered to be a more accurate value of how bright a projector is because of the testing process that takes into account more variables. Lumens just focuses on the amount of light outputted by a projector’s light source.
These variables that ANSI lumens takes into account include:
- Light source’s brightness
- Distance from screen
- Size of the screen
- Projector lens
- Ambient light
- Contrast and colour
The brightness of the light source used factors into the overall brightness whether it’s a traditional lamp, laser or LED source. The distance from the screen will impact how far that light has to travel, and there’s the consideration of how big the screen itself is. A bigger screen that’s further away requires higher levels of brightness.
The quality of the lens will aid brightness, as a higher quality lens typically offers a better performance than a lower quality one. The amount of ambient light in a room can have a negative impact as the light from the projector and the surrounding environment can blend into one, making the image look washed out and harder to see. However, while having a brighter projector can help, closing the curtains or watching in a dark room without ambient light are easier solutions.
And last there’s contrast and colour to consider. Brighter projectors can produce better contrast (as long as they can produce good black levels); while the brighter the light source is, the more colours the projector can describe.
ANSI lumens takes all these variables into account, but the method of calculating ANSI lumens is through a checkerboard test pattern that measures brightness across 9 zones. It uses the average of the brightness levels across those nine zones to calculate the brightness of the projector’s light source.
ANSI lumens vs lumens
ANSI lumens is generally considered to be the more accurate method of calculating a projector’s brightness.
It takes into account more variables and the testing method is standardised, ensuring a more consistent measurement for brightness, which makes it easier to compare one projector against another if they’ve gone through the ANSI lumens testing process.
Lumens lacks this standardised approach to testing. As it doesn’t tend to take into account the myriad variables that could affect brightness – it only deals with how much light the source produces that’s visible to the human eye – it’s considered to be the less accurate of the two.
How to calculate ANSI lumens from lumens
If you’re looking at a projector that doesn’t say how bright it is in ANSI lumens, you can calculate how bright it could be by converting the lumens figure.
This doesn’t give the most accurate value considering the projector likely hasn’t gone through the ANSI lumens testing process, but it is generally considered that the lumens figure is divided by 2.4 to give you a number in ANSI lumens.
A projector that claims 1000 lumens of brightness divided by 2.4 would come out to be 418 ANSI lumens.
Are ANSI lumens better than lumens?
Given the process used to calculate ANSI lumens, it is considered to be the more accurate of the two.
If you see a projector with ISO lumens that’s a another method of calculating brightness to both ANSI and traditional lumens.
Even though ANSI lumens figures are generally lower than lumens, don’t take that to be a sign that the projector is necessarily worse. Projectors that have gone through the ANSI lumens process take into account more variables that could impact brightness compared to what lumens does, and are more relevant to your viewing environment.
In this case, a higher brightness value in lumens does not always mean that the projector is brighter or better. As always, research before you buy.
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