What’s a Nit? – Bob’s Tech Talk Tuesday

Let’s set the basis

The term NIT (Latin, Nitere; to shine) is often used in the world of LED and digital signage displays and stands only for the measurement of light power coming from the LED display. The mathematical definition of NIT’s is the following: One candela per meter squared (m²) measured at 1 meter from the light source.

Let’s get rid of mathematical definitions and just use plain English, please

Let me rephrase that into plain English. Put a lit candle in a window which measures 1 meter tall by 1 meter wide. Stand one meter away from the window and measure the light power and that will equal 1 NIT. 10,000 candles in the same window and you will have 10,000 NITs! and most likely a fire hazard…

Now to properly do this NIT reading, we should be in a controlled environment such as a complete dark room without ambient light as diffraction of light plays an important role on the transmission of light.

The nit race of LED manufacturers and how it could become absurd

In the past few years, NITs have wrongly become the corner stone specification of quality of a display. In other words, when comparing the output of one display, say 10,000 NITS, with another one at 8000 NITS, it was widely assumed that 10,000 was better. The race was on in the mid 2000’s to get to 10,000 NITS of brightness amongst the LED manufacturers. However, you only really need 4500 nits to overpower the sun. And keep in mind that the ultimate goal of a digital sign is to be clearly visible during a sunny day – and not becoming a “local Sun”, if you know what I mean….

Ah and don’t forget that nits have an impact on power consumption

More NITs also means power consumption: The more NITs of power produced, the more your average running costs of a display will be. Like an automobile, the more horsepower the motor has, generally it is often accompanied by an increase in fuel consumption.

Why using a LED screen at 100% of its nit capacity is a bad idea

‘Dialing back’ your LED screen from 10,000 to 8,000 nits is most of the time a bright move – that what we do at Nummax by the way. By doing so, you preserve the longevity and quality image of your display without impacting the reach of your LED screen. Less power pushing through to drive the LEDs means also less heat, less degradation, less power consumption and better overall image quality for a decade – and not 5 years!

Oh, and by the way, there is a direct inverse relationship between data scans, refresh rate and NIT output. You increase one, you sacrifice another. 10,000 NITs at 3840 Hz I think not (“yet”)! But that will come in another blog, stay tuned.