Cyan LS

Hi All;
From what I have learned in this forum and from various sources, the cyan or green LS should last almost a lifetime before losing its brightness, and produce the most efficient light. Is this correct?

Yes, the Arc LS is slightly underdriven if I remember right so it should last forever. You can expect the shortest life (though still really long) out of a white LS because of the phosphor coating. On white LEDs (think 5mm Nichia) the coating degrades relatively quickly and there is a loss of output efficiency as a result. Lumileds (who makes the LS) claims that the way they assemble the emitter prevents this problem.

Colored LEDs are generally more efficient than white. This is mainly due to the phosphor layer in the whites which loses some energy in the conversion process (they use a blue LED with a phosphorous coating that converts it to spread-spectrum white light).

I think red LEDs are the most efficient in actual light output, but our eyes aren't as sensitive to those wavelengths as we are to green.

I think the orangish-red LS is supposed to be the overall winner for perceived brightness (according to Peter G). In non-LS lights, the turquoise color seems to be the winner.

The LS HD gives you a more ideal flashlight beam with a more focused hotspot than the LD. The total light output is the same for non-whites (the white HD introduced a new process that is more efficient).

So... the winner for long life and brightness is either an orangish-red or a cyan LS (I don't have either so I'm going on what others have said) and a HD version will give you the most focused output. Most people seem to prefer white, though, because of the improved color rendition and beam quality. Yes, the phosphor coating has a good effect, too--it makes the beam smoother.

Someone please correct me if I'm going astray here...

- Russ

R2,

I have drawn the same conclusions based on what I have read here and elsewhere and in fact am waiting on both a Cyan and Red-Orange LS that have been bouncing around in UPS's system for a week. Given Peter's adherance to driving the LED's to spec and the fact that the flashlights won't be on all the time, I am confident that these lights will be passed on to the next generation in my family. Of course in my case, that might be tomorrow.

r2 is correct. I have the white LS plus a LD cyan and a HD orange red. The orange red is very bright - twice the perceived brightness of the cyan. The beam also is nicer then the LD cyan ( now I wish I had a HD cyan to compare).But I'm not sure what I will use the red for. The cyan is great for outdoor use, hiking mainly. Activites where you do not need to know the color of objects, you just need a bright light. But the light I use the most is the white LS.

dark star,

Use the red/orange to see through the green brush while in the woods. Please experiment if you get a chance, and see for yourself which color penetrates the forest better.