Ad
related to: luminance levels measured in watts conversion
Search results
Results From The WOW.Com Content Network
Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. [1] It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls within a given solid angle .
Several measures of light are commonly known as intensity: Radiant intensity, a radiometric quantity measured in watts per steradian (W/sr) Luminous intensity, a photometric quantity measured in lumens per steradian (lm/sr), or candela (cd) Irradiance, a radiometric quantity, measured in watts per square meter (W/m 2)
A comparison of the watt and the lumen illustrates the distinction between radiometric and photometric units. The watt is a unit of power. We are accustomed to thinking of light bulbs in terms of power in watts. This power is not a measure of the amount of light output, but rather indicates how much energy the bulb will use.
The lux (symbol: lx) is the unit of illuminance, or luminous flux per unit area, in the International System of Units (SI). [1] [2] It is equal to one lumen per square metre.In photometry, this is used as a measure of the irradiance, as perceived by the spectrally unequally responding human eye, of light that hits or passes through a surface.
Standard SMPTE cinema screen luminance [10] 80 cd/m 2: Monitor white in the sRGB reference viewing environment 250 cd/m 2: Peak luminance of a typical LCD monitor [11] [12] 700 cd/m 2: Typical photographic scene on overcast day [7] [9] [12] 10 3: kcd/m 2: 1 kcd/m 2: Cloudy sky at noon [4] [12] 2 kcd/m 2: Average cloudy sky [5] [12] 2.5 kcd/m 2 ...
In photometry, luminous intensity is a measure of the wavelength-weighted power emitted by a light source in a particular direction per unit solid angle, based on the luminosity function, a standardized model of the sensitivity of the human eye. The SI unit of luminous intensity is the candela (cd), an SI base unit.
Luminance: L v: candela per square metre: cd/m 2 (= lm/(sr⋅m 2)) L −2 ⋅J: Luminous flux per unit solid angle per unit projected source area. The candela per square metre is sometimes called the nit. Illuminance: E v: lux (= lumen per square metre) lx (= lm/m 2) L −2 ⋅J: Luminous flux incident on a surface Luminous exitance, luminous ...
In SI units illuminance is measured in lux (lx), or equivalently in lumens per square metre (lm·m −2). [2] Luminous exitance is measured in lm·m −2 only, not lux. [4] In the CGS system, the unit of illuminance is the phot, which is equal to 10 000 lux. The foot-candle is a non-metric unit of illuminance that is used in photography. [5]