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Units point of interest, the luminous flux per area is called "illuminance" and measured in lux (lumens per square meter) or footcandles (lumens per square foot
by wlesieutre 10y ago
Units point of interest, the luminous flux per area is called "illuminance" and measured in lux (lumens per square meter) or footcandles (lumens per square foot)
- roesel 10y ago`footcandle` is a ridiculous name for a unit.
- ouid 10y agoit's not even the right dimension.
- contingencies 10y agoCatchy though. Same style: Toebright?[0] Fingerbling? Nosefire? This sort of fundamentally physical compound noun has a sort of medieval ring to it. [0] In homage to Madeleine
- wlesieutre 10y agoOriginally comes from 1 fc being the illuminance on a surface 1 foot away from a 1 candela light source. A candela being roughly the intensity of light from a candle. Intensity (candelas) breaking down to lumens per steradian. They're a measure of how bright a light is in a particular direction, rather than its total light output (which is lumens). And steradians, for the unfamiliar, being a measure of "solid angle". Steradians are to 3D angles as radians are to 2D angles. A 1 steradian solid angle projects out to an area of 1 unit^2 on the surface of a unit sphere. Fun stuff!
- wlesieutre 10y agoOther fun fact, 1 fc = 10.7639 lux, because that's how many square feet make up a square meter. But in the lighting industry we just pretend 1 fc = 1 lux for most conversions, because eh, close enough.