Talk:Radiant flux

Latest comment: 6 years ago by MaggieGaye in topic correct terminology

Untitled edit

Concerning radiant flux for typical household lightbulbs, does this mean that the wattage expressed on the bulb is integrated with respect to ALL wavelengths or just the ones in the visible range? —Preceding unsigned comment added by Xcelerate (talkcontribs) 02:37, 12 February 2008 (UTC)Reply

Neither. The wattage of a lightbulb is the amount of electrical power it consumes. It has nothing whatsoever to do with how much light the bulb produces, except that conventional incandescent light bulbs tend to produce luminous flux that varies directly (but not linearly) with their power consumption. See Luminous efficacy for more on the efficiency of light bulbs.--Srleffler (talk) 05:58, 12 February 2008 (UTC)Reply
I undid your last edit, removing the following: "The power is integeated with respect to both wavelength and area, meaning that shorter wavelengths have more contribution to the radiant flux." I felt that this was confused and/or incorrect. The radiant flux is total power, so of course it is integrated with respect to wavelength and area. It's integrated with respect to solid angle too, if you like. Total is total. I'm not sure what you had in mind regarding shorter wavelengths. Shorter wavelengths have more energy (or flux) per photon, but if that's what you had in mind you would have had to spell that out, and that would go beyond what should be in the first paragraph of the article. --Srleffler (talk) 06:02, 12 February 2008 (UTC)Reply


Surely the use of the word flux in the case (radiant flux) is confusing and at odds with that which is accepted in other fields, namely that it is a measure of something per unit area, eg W/m²...? Jdpipe (talk) —Preceding undated comment was added at 08:01, 20 October 2008 (UTC).Reply

See Flux. The word has two common meanings in physics, with the usage varying by subfield. This is an example of meaning #2, which is common in electromagnetism. --Srleffler (talk) 21:49, 20 October 2008 (UTC)Reply

correct terminology edit

I wonder about the quantity "Radiant flux" as well as "Spectral power". According to IESNA LM-79-08 chapter 12.1 I would think the right expression for "W/nm" is "Spectral radiant flux". What source is used by using "Spectral power"? — Preceding unsigned comment added by 89.247.8.48 (talk) 06:12, 14 December 2012 (UTC)Reply

Power Spectral Density is the most popular. MaggieGaye (talk) 00:12, 16 March 2018 (UTC)Reply