Search results
Results From The WOW.Com Content Network
Starlight clear moonless night sky excluding airglow [ 1] 10 −3. 1 millilux. 2 millilux. Starlight clear moonless night sky including airglow [ 1] 10 −2. 1 centilux. 1 centilux. Quarter Moon.
However, the same 1000 lumens spread out over 10 square metres produces a dimmer illuminance of only 100 lux. Achieving an illuminance of 500 lx might be possible in a home kitchen with a single fluorescent light fixture with an output of 12 000 lumens. To light a factory floor with dozens of times the area of the kitchen would require dozens ...
Luminous flux (in lumens) is a measure of the total amount of light a lamp puts out. The luminous intensity (in candelas) is a measure of how bright the beam in a particular direction is. If a lamp has a 1 lumen bulb and the optics of the lamp are set up to focus the light evenly into a 1 steradian beam, then the beam would have a luminous ...
The lumen (symbol: lm) is the unit of luminous flux, a measure of the perceived power of visible light emitted by a source, in the International System of Units (SI). ). Luminous flux differs from power (radiant flux) in that radiant flux includes all electromagnetic waves emitted, while luminous flux is weighted according to a model (a "luminosity function") of the human eye's sensitivity to ...
1 candela (modern definition) Candlepower (abbreviated as cp or CP) is a unit of measurement for luminous intensity. It expresses levels of light intensity relative to the light emitted by a candle of specific size and constituents. The historical candlepower is equal to 0.981 candelas. In modern usage, candlepower is sometimes used as a ...
The flow of 1 / 1.602 176 634 × 10 −19 times the elementary charge e per second, ... lumen: lm luminous flux: cd⋅m 2 /m 2: cd⋅sr ... 1 000 000 000 000 ...
CGS. 1.076 × 10−3 phots. A foot-candle (sometimes foot candle; abbreviated fc, lm/ft2, 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 ...
A 25 W compact fluorescent light bulb puts out around 1700 lumens; if that light is radiated equally in all directions (i.e. over 4 π steradians), it will have an intensity of = / = . Focused into a 20° beam (0.095 steradians), the same light bulb would have an intensity of around 18,000 cd within the beam.