NIT and Candela (cd/m 2) measure how bright a light source is.ConclusionĪ significant difference between these brightness units is whether or not we’re trying to measure light is that received (illuminance) by an object or emitted (luminance) by an object. The TV and display industry have been using the term NIT instead of Candela, which is probably why NIT became widely used in tech media. NIT and cd/m 2 represent the same thing and can be used interchangeably, although it’s better to be consistent. NIT is equivalent to Candela (cd/m 2), but is not part of the International System of Units (abbreviated SI, from Systeme International, in French). It comes from the Latin Nitere, which means “to shine.” NIT is a metric for measuring luminance, which is how much light an object emits.

If you want to dig, check the Lumen page of Wikipedia.

Today, we have a much more scientific and complex definitions of a Candell, but for a basic understanding, the description above is sufficient. The Lumen is defined from the Candella, a topic that we covered for the first 1000 NITs smartphone, the LG G7.Ĭandella is a very old brightness metric that is based on “whale oil candles.” 1 Candella is the light emitted by one such candle, which was “standard” at the time. Lumen is not to be confused with LUX, which measures how much light is received (illuminance) by a surface. The luminance is also expressed in Candela per square-meter, or cd/m 2. Lumen is commonly used in the context of light bulbs or video-projectors as a metric for their brightness power. Lumen is a measure of how much light is emitted ( luminance, luminous flux) by an object. The table below gives a rough idea of LUX values that would be measured in different situations. In the same way, if you get very close to even a candle, the brightness will increase. The initial light energy is spread to an ever-larger area and becomes dimmer. This is why light becomes dimmer as you measure it farther away from the light source. If 1000 lumens is spread across 10 square meters, that’s 100 LUX. For instance, if a luminous flux of 1000 lumens is spread across 1 square meter, that’s 1000 LUX. The luminous flux is similar to a quantity of (light) energy, and if you spread it over a larger surface area, the light will become dimmer. For instance, if we say that it is a photo that was shot at 0.5 LUX, it means that we measured 0.5 LUX right where the subject was. Most light meters you can buy have a ~0.8-inch hemispherical light sensor and have a range of 0.1 to 200,000 for the basic models.įor photography purposes, we can set the sensor right in front of the subject and measure the LUX number at that point. In the context of this site, we mention LUX ( Wikipedia page) as the brightness as measured by a light meter. LUX is a brightness measurement unit that represents the quantity of light (luminous flux, in lumen, explained below) that is received ( illuminance) by a surface and expressed in lumen per square meter, or lm/m 2.

Lumen vs candela vs lux