Jmdonev: 1 revision imported

2026-06-04T17:17:01Z

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Energy>Jmdonev at 16:55, 27 May 2026

2026-05-27T16:55:00Z

← Older revision		Revision as of 16:55, 27 May 2026
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	[[Category:Done ~~2015~~-09-06]]		[[Category:Done 2026-06-01]]
	<onlyinclude>The '''lumen''' ('''lm''') is the [[Units\|SI derived unit]] for [[light]] flux, which is the amount of light being ~~received~~ by a ~~surface~~.</onlyinclude><ref name=r>Rowlett Unit Dictionary. (Accessed Sept. 4, 2015). ''lumen (lm)'' [Online], Available: http://www.unc.edu/~rowlett/units/dictL.html#lumen</ref> ~~A lumen is defined as the amount of light being emitted into 1 unit of solid angle (1/4π of the area of a sphere) by a light source with a [[luminous intensity]] of 1 [[candela]].~~ Therefore a source of 1 candela will be putting out a total of 4π lumens.<Ref name=r/>		<onlyinclude>The '''lumen''' ('''lm''') is the [[Units\|SI derived unit]] for [[light]] flux, which is the amount of light being emitted into 1 unit of solid angle (1/4π of the area of a sphere) by a light source with a [[luminous intensity]] of 1 [[candela]].</onlyinclude><ref name=r>Rowlett Unit Dictionary. (Accessed Sept. 4, 2015). ''lumen (lm)'' [Online], Available: http://www.unc.edu/~rowlett/units/dictL.html#lumen</ref> Therefore a source of 1 candela will be putting out a total of 4π lumens.<Ref name=r/>

	<gallery caption="Both bulbs emit 800 lumens, however the ~~CFL~~ bulb uses less power to do so." ~~mode=packed heights=220px~~>		<gallery mode="packed" heights="220" caption="Figure 1. Both bulbs emit 800 lumens, however the LED bulb uses less electrical power to do so.">
	File:Incandescent Light Bulb.png\|Incandescent bulb: Requires 60 watts of power.<ref>Wikimedia Commons [Online], Available: https://upload.wikimedia.org/wikipedia/commons/3/3a/Gluehlampe_01_KMJ.jpg</ref>		File:Incandescent Light Bulb.png\|Incandescent bulb: Requires 60 watts of power.<ref>Wikimedia Commons [Online], Available: https://upload.wikimedia.org/wikipedia/commons/3/3a/Gluehlampe_01_KMJ.jpg</ref>
	File:~~CFLBulb~~.~~jpg~~\|~~CFL~~ bulb: Requires 13 watts of power.<ref>Wikimedia Commons [Online], Available: https://~~upload~~.wikimedia.org/~~wikipedia~~/~~commons/3/31/06_Spiral_CFL_Bulb_2010~~-03-~~08_(white_back)~~.jpg</ref>		File:LED-E27-Light-Bulb-1112 01lalalal.png\|LED bulb: Requires 9 watts of power.<ref>Wikimedia Commons (2021). (Accessed May 22, 2026). ''LED household light bulb with E27 Edison screw, with internal circuitry exposed'' [Online]. Available: https://commons.wikimedia.org/wiki/File:LED-E27-Light-Bulb-1112_01.jpg</ref>
	</gallery>		</gallery>

	[[Light bulb]]s are often rated in lumens in order to communicate their brightness. For example, a 13 [[watt]] [[~~CFL~~ light bulb]] and a 60 watt [[incandescent light bulb]] have the same brightness of 800 lumens~~, therefore the CFL~~ bulb accomplishes the same goal while using less [[power]].<ref>Energy Star. (Accessed Sept 4, 2015). ''Learn about brightness'' [Online], Available: http://www.energystar.gov/index.cfm?c=cfls.pr_cfls_lumens</ref><ref name=nrcan>Natural Resources Canada. (Accessed Sept 3, 2015). ''Facts About Compact Fluorescent Light Bulbs'' [Online], Available: http://www.nrcan.gc.ca/sites/oee.nrcan.gc.ca/files/files/pdf/equipment/CFL_Facts_e.pdf</ref>		[[Light bulb]]s are often rated in lumens in order to communicate their brightness. For example, a 9 [[watt]] [[LED light bulb]] and a 60 watt [[incandescent light bulb]] have the same brightness of 800 lumens. The LED bulb accomplishes the same goal while using less [[power]].<ref>Energy Star. (Accessed Sept 4, 2015). ''Learn about brightness'' [Online], Available: http://www.energystar.gov/index.cfm?c=cfls.pr_cfls_lumens</ref><ref name=nrcan>Natural Resources Canada. (Accessed Sept 3, 2015). ''Facts About Compact Fluorescent Light Bulbs'' [Online], Available: http://www.nrcan.gc.ca/sites/oee.nrcan.gc.ca/files/files/pdf/equipment/CFL_Facts_e.pdf</ref><ref>Volt Lighting (2026). (Accessed May 22, 2026). ''Lumens to Watts Conversion Chart: Choose the Right LED Bulb'' [Online]. Available: https://www.voltlighting.com/learn/lumens-to-watts-conversion-led-bulb</ref>

	==Lux==		==Lux==
	Lumens can be thought of as the "amount" of light within a beam ~~or angle given off by a source~~, ~~however it doesn't~~ explain how much light will arrive at any given distance from the source. The unit for this is '''lux''', which is equal to 1 lumen per square [[meter]]. ~~A full moon on a clear night is tremendously bright (high lumen value)~~, ~~however~~ the ~~lux received on~~ the ~~Earth is about 1/4 of a lumen per square meter. In comparison~~, ~~a light bulb will have an illumination of approximately 50 lux~~, ~~while direct [[sunlight]] can get up to 130,000 lux at~~ the ~~Earth's surface~~.~~<Ref>SI Units Explained. (Accessed Sept 4, 2015). ''Luminous Intensity'' [Online], Available: http://www.si-units-explained.info/luminosity/</ref>~~		[[File:Lichtmessung.svg.png\|thumb\|Figure 2. The difference between the Lumen, the Candela, and the Lux.<ref>Wikimedia Commons (2017). (Accessed May 22, 2026). ''Lichtmessung'' [Online]. Available: https://commons.wikimedia.org/wiki/File:Lichtmessung.svg</ref>]]
			Lumens can be thought of as the "amount" of light within a beam. However, lumens do not explain how much light will arrive at any given distance from the source. The unit for this is '''lux''', which is equal to 1 lumen per square [[meter]]. In Figure 2, the difference between the Lumen, the Candela, and the Lux is clearly represented.

			A full moon on a clear night is tremendously bright (high lumen value), however, the lux received on the Earth is about 1/4 of a lumen per square meter. In comparison, a light bulb will have an illumination of approximately 50 lux, while direct [[sunlight]] can get up to 130,000 lux on the Earth's surface.<ref>SI Units Explained. (Accessed Sept 4, 2015). ''Luminous Intensity'' [Online], Available: http://www.si-units-explained.info/luminosity/</ref>

			==For Further Reading==
			* [[LED light bulb]]
			* [[CFL light bulb]]
			* [[Lighting]]
			* [[Electrical energy]]
			* [[Energy]]
			* Or explore a [[Special:Random\|random page]]
	==References==		==References==
	{{reflist}}		{{reflist}}[[Category:Uploaded]]

J.williams: 1 revision imported

2015-09-18T16:52:22Z

1 revision imported

← Older revision	Revision as of 16:52, 18 September 2015
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Jmdonev at 19:27, 13 September 2015

2015-09-13T19:27:14Z

New page

[[Category:Done 2015-09-06]]
<onlyinclude>The '''lumen''' ('''lm''') is the [[Units|SI derived unit]] for [[light]] flux, which is the amount of light being received by a surface.</onlyinclude><ref name=r>Rowlett Unit Dictionary. (Accessed Sept. 4, 2015). ''lumen (lm)'' [Online], Available: http://www.unc.edu/~rowlett/units/dictL.html#lumen</ref> A lumen is defined as the amount of light being emitted into 1 unit of solid angle (1/4π of the area of a sphere) by a light source with a [[luminous intensity]] of 1 [[candela]]. Therefore a source of 1 candela will be putting out a total of 4π lumens.<Ref name=r/>

<gallery caption="Both bulbs emit 800 lumens, however the CFL bulb uses less power to do so." mode=packed heights=220px>
File:Incandescent Light Bulb.png|Incandescent bulb: Requires 60 watts of power.<ref>Wikimedia Commons [Online], Available: https://upload.wikimedia.org/wikipedia/commons/3/3a/Gluehlampe_01_KMJ.jpg</ref>
File:CFLBulb.jpg|CFL bulb: Requires 13 watts of power.<ref>Wikimedia Commons [Online], Available: https://upload.wikimedia.org/wikipedia/commons/3/31/06_Spiral_CFL_Bulb_2010-03-08_(white_back).jpg</ref>
</gallery>

[[Light bulb]]s are often rated in lumens in order to communicate their brightness. For example, a 13 [[watt]] [[CFL light bulb]] and a 60 watt [[incandescent light bulb]] have the same brightness of 800 lumens, therefore the CFL bulb accomplishes the same goal while using less [[power]].<ref>Energy Star. (Accessed Sept 4, 2015). ''Learn about brightness'' [Online], Available: http://www.energystar.gov/index.cfm?c=cfls.pr_cfls_lumens</ref><ref name=nrcan>Natural Resources Canada. (Accessed Sept 3, 2015). ''Facts About Compact Fluorescent Light Bulbs'' [Online], Available: http://www.nrcan.gc.ca/sites/oee.nrcan.gc.ca/files/files/pdf/equipment/CFL_Facts_e.pdf</ref>

==Lux==
Lumens can be thought of as the "amount" of light within a beam or angle given off by a source, however it doesn't explain how much light will arrive at any given distance from the source. The unit for this is '''lux''', which is equal to 1 lumen per square [[meter]]. A full moon on a clear night is tremendously bright (high lumen value), however the lux received on the Earth is about 1/4 of a lumen per square meter. In comparison, a light bulb will have an illumination of approximately 50 lux, while direct [[sunlight]] can get up to 130,000 lux at the Earth's surface.<Ref>SI Units Explained. (Accessed Sept 4, 2015). ''Luminous Intensity'' [Online], Available: http://www.si-units-explained.info/luminosity/</ref>

==References==
{{reflist}}

Lumen - Revision history

Jmdonev: 1 revision imported

Energy>Jmdonev at 16:55, 27 May 2026

J.williams: 1 revision imported

Jmdonev at 19:27, 13 September 2015