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.
![lumens to candela lumens to candela](https://i.pinimg.com/originals/57/3c/2c/573c2ccfebdbd8cb2346a38e2435726b.jpg)
![lumens to candela lumens to candela](https://www.fireflier.com/wp-content/uploads/2018/06/footcandle-vs-lux.png)
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.
![lumens to candela lumens to candela](https://www.lumen.it/content/images/thumbs/0000716_candela-70x150mm-avorio-ivory.jpeg)
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.