Nits, Lumens, and Brightness on TVs and Projectors

If you are about to purchase a TV or video projector and haven't shopped for either in several years, things may be more confusing than ever. Whether you look at online or newspaper ads or go to your local dealer cold turkey, there are so many tech terms thrown out, many consumers end up pulling out their cash and hoping for the best.

This information applies to TVs from a variety of manufacturers including, but not limited to, those made by LG, Samsung, Panasonic, Sony, and Vizio and video projectors from manufacturers such as Epson, Optoma, BenQ, Sony, and JVC.

One "techie" term that has entered the TV mix is HDR. HDR (High Dynamic Range) is all the rage amongst TV makers, and there is a good reason for consumers to take notice.

Although 4K has improved resolution, HDR tackles another important factor in both TV and video projectors, light output (luminance).

The goal of HDR is to support increased light output capability so that displayed images have characteristics that are more like the natural light conditions we experience in the "real world."

As a result of HDR implementation, two established technical terms have risen to prominence in TV and video projector promotion: Nits and Lumens.

Although the term Lumens has been a mainstay of video projector marketing for some years, when shopping for a TV, consumers are now being hit with the term Nits by TV makers and persuasive salespersons.

Before HDR was available when consumers shopped for a TV, one brand/model may have looked "brighter" than another, but that difference wasn't really quantified, you just had to eyeball it.

With HDR offered on an increasing number of TVs, light output (notice I did not say brightness, which will be discussed later) is quantified in Nits — more Nits, means a TV can output more light, with the primary purpose to support HDR — either with compatible content or a generic HDR effect generated via a TV's internal processing.

Here is how Nits and Lumens are defined.

To put this into perspective, an average TV may have the capability to output 100 to 200 Nits, while HDR-compatible TVs may have the ability to output 400 to 2,000 nits.

In relation to Nits, an ANSI lumen is the amount of light that is reflected off of a one square meter area that is one meter from a one candela light source. Think of an image displayed on a video projection screen, or wall as the moon, which reflects light back to the viewer.

1000 ANSI Lumens is the minimum that a projector should be able to output for home theater use, but most home theater projectors average from 1,500 to 2,500 ANSI lumens of light output. On the other hand, multi-purpose video projectors (use for a variety of roles, which may include home entertainment, business, or educational use, may be able to output 3,000 or more ANSI lumens).

One Nit represents more light than 1 ANSI lumen. The mathematical difference between Nits and Lumens is complex. However, for the consumer comparing a TV with a video projector, one way to put it is 1 Nit as the approximate equivalent of 3.426 ANSI Lumens.

Using that general reference point, in order to determine the approximate amount of Nits comparable to an approximate number of ANSI lumens, you can multiply the number of Nits by 3.426. If you want to do the reverse, divide the number of Lumens by 3.426.

Here are some examples:

For a video projector to achieve a light output equivalent to 1,000 Nits (keep in mind that you are lighting up the same amount of room area and room lighting conditions are the same)—it needs to output as much as 3,426 ANSI Lumens, which is out of range for most dedicated home theater projectors.

However, a projector that can output 1,713 ANSI Lumens, which is easily attainable, can approximately match a TV that has a light output of 500 Nits.

Getting more precise, other factors, such as TV screen size also affects the Nits/Lumens relationship. For example, a 65-inch TV that puts out 500 nits will have approximately four times the lumens output of a 32-inch TV putting out 500 nits.Taking that variation into account, when comparing nits, screen size, and lumens, the formula used should be Lumens = Nits x Screen Area x Pi (3.1416). The screen area is determined by multiplying screen width and height stated in square meters.Using the 500 nit 65-inch TV which as 1.167 square meter screen area, the lumens equivalent would be 1,833.

Although all the above "techie" info on Nits and Lumens provides a relative reference, in real-world applications, numbers are only part of the story.

Factors such as viewing in a darkened room, as opposed to a partially lit room, screen size, screen reflectivity (for projectors), and seating distance, more or less Nit or Lumen output may be required to get the same desired visual impact.

One analogy to approach the HDR/Nits/Lumens issue is in the same way you should approach amplifier power specifications in audio. Just because an amplifier or home theater receiver claims to deliver 100 watts per channel, doesn't mean that it outputs that much power all the time.

Although the capability of being able to output 100 watts provides an indication on what to expect for musical or movie soundtrack peaks, most of the time, for voices, and most music and sound effects, that same receiver only needs to output 10 watts or so for you to hear what you need to hear.

For TVs and Video Projectors, Nits and ANSI Lumens are both measures of light output (Luminance). However, where does the term Brightness fit in?

Measuring light output with reference to the relationship between Nits and Lumens deals with a lot of math and physics, and boiling it down into a brief explanation isn't easy. So, when TV and video projector companies hit consumers with terms such as Nits and Lumens without context, things can get confusing.

However, when considering light output, here are some guidelines to keep in mind.

Just as with any specification or tech term that is thrown at you by a manufacturer or salesperson, don't obsess. Nits and Lumens are only one part of the equation when considering the purchase of a TV or video projector.

Take the entire package into consideration, which not only includes stated light output but how the entire image looks to you in terms of :

Also keep in mind that if you desire an HDR-equipped TV, you need to take the additional content access requirements into consideration (4K Streaming and Ultra HD Blu-ray Disc).

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