Efficiancy ?

[Christoph]

I have a "lot" of white emitters and am going to use some of them for my motorcycle lighting. How inefficient will they be vs red leds behind red lenses? I have Lux, Cree and SSC they are bright.Will they work from behind red lens'?Are the losses great?
TIA
Chris

 

[evan9162]

You are far better off to use a red LED rather than a white LED behind a filter. The brightest white LEDs are "cool white" with a color temperature in the 5500k range. They are rather weak in the red spectrum.

If all you've got are whites and don't want to bother getting any more LEDs, then the whites probably will work fine, but you'll likely get several times more light with an equivalently powered red LED (i.e. a red luxeon at 350mA will be several times brighter than a white rebel at 350mA behind a red filter).

 

[Christoph]

Thanks Evan thats what I thought,would that also hold for an amber lens?
C

 

[evan9162]

Thanks Evan thats what I thought,would that also hold for an amber lens?
C

It would pretty much hold true for any single color.

 

[Marduke]

There is a good deal of material here on the affects of filtering white LED's with colored filters.

http://www.candlepowerforums.com/vb/showthread.php?t=173777
http://www.candlepowerforums.com/vb/showthread.php?t=174183

Amber filters would be more efficient than red, but for tail lights, either would probably work just as well as the stock incans, or better.