When.com Web Search

Search results

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

    en.wikipedia.org/wiki/Foot-candle

    A foot-candle (sometimes foot candle; abbreviated fc, lm/ft 2, or sometimes ft-c) is a non-SI unit of illuminance or light intensity. The foot-candle is defined as one lumen per square foot. This unit is commonly used in lighting layouts in parts of the world where United States customary units are used, mainly the United States. [ 1 ]

  3. Foot-lambert - Wikipedia

    en.wikipedia.org/wiki/Foot-lambert

    A foot-lambert or footlambert (fL, sometimes fl or ft-L) is a unit of luminance in United States customary units and some other unit systems. A foot-lambert equals 1/π or 0.3183 candela per square foot, or 3.426 candela per square meter (the corresponding SI unit).

  4. Illuminance - Wikipedia

    en.wikipedia.org/wiki/Illuminance

    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]

  5. Guide number - Wikipedia

    en.wikipedia.org/wiki/Guide_number

    Unit: Lux (lumens per square meter) Definition: In the context of photography, is the measure of the intensity, or concentration per unit area, of eye-adjusted visible light impinging upon a surface. In common vernacular, it is the brightness of light measured at the surface of a photographic subject. Luminous exposure Symbol: H v Unit: Lux⋅ ...

  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 ...

  7. Talk:Foot-candle - Wikipedia

    en.wikipedia.org/wiki/Talk:Foot-candle

    2 convert footcandles and lux to candelas. 5 comments. 3 calculating foot-candles with a camera. 2 comments. 4 Incorrect title? 1 comment. 5 Inappropriate image. 3 ...

  8. Luminous intensity - Wikipedia

    en.wikipedia.org/wiki/Luminous_intensity

    lux (= lumen per square metre) lx (= lm/m 2) L −2 ⋅J: Luminous flux incident on a surface Luminous exitance, luminous emittance M v: lumen per square metre lm/m 2: L −2 ⋅J: Luminous flux emitted from a surface Luminous exposure: H v: lux second: lx⋅s L −2 ⋅T⋅J: Time-integrated illuminance Luminous energy density ω v: lumen ...

  9. Orders of magnitude (illuminance) - Wikipedia

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

    1 lux < 1 lux: Extreme of darkest storm clouds, sunset or sunrise 10 1: 1 decalux: 40 lux: Fully overcast, sunset or sunrise 10 2: 1 hectolux < 200 lux: Extreme of darkest storm clouds, midday 400 lux: Sunrise or sunset on a clear day (ambient illumination) 10 4: 10 kilolux: 10–25 kilolux: Typical overcast day, midday 20 kilolux