Re: What's the brightest LED ? what's the chance they will replace Flourescent lights in
Comparaison between incandescent, fluorescent and led lighting is not so easy...
First, there is a psychological effect, and according to Kruithof's curve, for a same subjective perception of comfort (and a good comfort is often perceived as a good light output... yes!), actually less "warm" light output is needed than "cold" light output.
(http://www.learn.londonmet.ac.uk/packages/clear/visual/people/ambience/colour/)
So, incandescent lamps have a poor efficiency, but as the light seems "warm" (3000 K), this "pleasant" efficiency is not perceived as so bad. On the contrary, a led beam may seem not very bright because its color temparature is "cold" (6000 K).
Subjectively: "not pleasant" is perceived as "not good", and at the end "not good" is perceived as "not bright enough"...
Second, for an identical overall flux, light distribution is not the same for incandescent/led and fluorescent.
Incandescent and led allow to use a reflector, and the narrow beam will give a perception of a bright source.
Fluorescent, despite its very good efficiency, does not allow to use a beam, so :
- for low intensity lamps (flashlights), much light is "lost" so it doesn't seem powerful nor bright at all => led seems more efficient, more brighter (in subjective terms);
- for high intensity lamps (indoor lighting, at home or at the office,...), where general lighting is required, fluorescent lamps give much homogeneous light, so they seem brighter than leds or incandescent.
Third, don't forget life duration... Many lighting system efficiency decrease after a few hours: it is bright in the shop, it is poor at home... Especially when fluo or led lamps are boosted!
I hope this will balance the objective (true) values given above, and help to understand why a fluorescent flashlight seem less bright than a led flashlight, despite lm/w efficiency values.
(And sorry for my English, this is not my mother language)