Talk:Luminous flux
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The defintion given on this page is precisely the definition of lumen, the physical unit in which luminous flux is allegedly measured. --Smack 19:54, 4 Jan 2005 (UTC)
The caption which states that "one lumen is defined as the amount of light that falls on a unit spherical area at unit distance from a light source of one candela" is not correct.
The correct physical definition for the lumen is as follows:
"One lumen is the luminous flux produced by a point source with a luminous intensity of one candela over a solid angle of one sterradian".
To state this mathematically: PHI = I x OMEGA
In unit form: [lm] = [cd x sr]
Where PHI is the luminous flux, given in lumen [lm], I is the luminous intensity given in candela [cd] and OMEGA is the solid angle given in sterradian [sr].
The candela is one of the seven fundamental SI units and the sterradian is one of the two supplementary SI units.
The correction, as given above, regardind the definition of the lumen was provided by Jerry N. Reider jnreider@anahuac.mx on June 04, 2005 at 00:32 UTC
It would be good to provide some examples of typical luminous flux of common light sources - at least the luminous flux of a 100W incandecent bulb - to give reader a better understanding of different values of luminous flux. I, personally, am not an expert in bulbs so I would appreciate someone knowledgeble add this information to the article. Thank you!Matveims 01:30, 2 December 2005 (UTC)
- I added as an example the luminous flux of a 100W light bulb. The page on incandescent light bulbs has more information on the efficiency of different light sources. A table of example values might be useful here too, if someone feels like putting one together.--Srleffler 04:09, 2 December 2005 (UTC)
