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2. Orders of magnitude (illuminance) - Wikipedia

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

   Fluorescent lamp [5] [6] 10 5: 75 kcd/m 2: Low pressure sodium-vapor lamp [6] 130 kcd/m 2: Frosted incandescent light bulb [5] [6] [12] 10 6: Mcd/m 2: 600 kcd/m 2: Solar disk at horizon [5] 10 7: 7 Mcd/m 2: Filament of a clear incandescent lamp [13] 10 8: 100 Mcd/m 2: Possible retinal damage [4] 10 9: Gcd/m 2: 1.6 Gcd/m 2: Solar disk at noon [5 ...

3. Fluorescent-lamp formats - Wikipedia

   en.wikipedia.org/wiki/Fluorescent-lamp_formats

   High-lumen retrofit lamps for 40W T12 lamps in North America. Popular tube diameter in Japan; Circular 32W and 40W T10 lamps (Older versions of the 32W and 40W T9 lamps) T12 T38 1 + 1 ⁄ 2: 38.1 G13 bi-pin; Fa8 single-pin; R17d recessed double contact; One of the first diameters of fluorescent lamps, with the 15W T12 and 20W T12 having been ...

4. Fluorescent lamp - Wikipedia

   en.wikipedia.org/wiki/Fluorescent_lamp

   The efficacy of fluorescent tubes ranges from about 16 lumens per watt for a 4 watt tube with an ordinary ballast to over 100 lumens per watt [51] with a modern electronic ballast, commonly averaging 50 to 67 lm/W overall. [52] Ballast loss can be about 25% of the lamp power with magnetic ballasts, and around 10% with electronic ballasts.

5. Luminous flux - Wikipedia

   en.wikipedia.org/wiki/Luminous_flux

   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 ...

6. Lumen (unit) - Wikipedia

   en.wikipedia.org/wiki/Lumen_(unit)

   Lamps used for lighting are commonly labelled with their light output in lumens; in many jurisdictions, this is required by law. A 23 W spiral compact fluorescent lamp emits about 1,400–1,600 lm. [4] [5] Many compact fluorescent lamps and other alternative light sources are labelled as being equivalent to an incandescent bulb with a specific ...

7. Luminous efficacy - Wikipedia

   en.wikipedia.org/wiki/Luminous_efficacy

   Luminous efficacy of radiation measures the fraction of electromagnetic power which is useful for lighting. It is obtained by dividing the luminous flux by the radiant flux . [ 4 ] Light wavelengths outside the visible spectrum reduce luminous efficacy, because they contribute to the radiant flux, while the luminous flux of such light is zero.