When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Illuminance - Wikipedia

    en.wikipedia.org/wiki/Illuminance

    Illuminance diagram with units and terminology In photometry , illuminance is the total luminous flux incident on a surface, per unit area . [ 1 ] It is a measure of how much the incident light illuminates the surface, wavelength-weighted by the luminosity function to correlate with human brightness perception. [ 2 ]

  3. Luminance - Wikipedia

    en.wikipedia.org/wiki/Luminance

    The sun has a luminance of about 1.6 × 10 9 cd/m 2 at noon. [3] Luminance is invariant in geometric optics. [4] This means that for an ideal optical system, the luminance at the output is the same as the input luminance. For real, passive optical systems, the output luminance is at most equal to the input.

  4. Photometry (optics) - Wikipedia

    en.wikipedia.org/wiki/Photometry_(optics)

    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 ...

  5. Orders of magnitude (illuminance) - Wikipedia

    en.wikipedia.org/wiki/Orders_of_magnitude...

    Illuminance [ edit ] To help compare different orders of magnitude , the following list describes various source in lux , which is a lumen per square metre .

  6. Lux - Wikipedia

    en.wikipedia.org/wiki/Lux

    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.

  7. Luminous intensity - Wikipedia

    en.wikipedia.org/wiki/Luminous_intensity

    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 ...

  8. Luminous flux - Wikipedia

    en.wikipedia.org/wiki/Luminous_flux

    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 ...

  9. Brightness - Wikipedia

    en.wikipedia.org/wiki/Brightness

    When appearing on light bulb packages, brightness means luminous flux, while in other contexts it means luminance. [5] Luminous flux is the total amount of light coming from a source, such as a lighting device. Luminance, the original meaning of brightness, is the amount of light per solid angle coming from an area, such as the sky.