SureFire L4 uv-vis microspectrophotometer results

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glen

Newly Enlightened
Joined
Jun 7, 2003
Messages
78
Surefire_L4g.GIF
 
My spectrometer is broken, so I probably won't be graphing LEDs or flashlights anymore. Not anytime soon, anyway. /ubbthreads/images/graemlins/jpshakehead.gif I'm glad *somebody* else here has access to one. /ubbthreads/images/graemlins/grin.gif
(The charts are nicer than the ones my spectrometer created, too!) /ubbthreads/images/graemlins/smile.gif
 
The visible spectrum is between 400 and 700nm, and green is i'm guessing 515nm, so does the spike at 430nm balance the red shifted bigger spike to make the eye believe it is seeing white? It seems the green is winning for this L4. How do others read the graph? Do the two spikes represent two diffrent phosphors? Dierik
 
The L4 is a touch green.
If anyone wants to mail me their L4, PM me, I will run it so we can see how gree or white it is.
 
Re: SureFire L4 uv-vis microspectrophotometer resu

[ QUOTE ]
annomundi said:
The visible spectrum is between 400 and 700nm, and green is i'm guessing 515nm, so does the spike at 430nm balance the red shifted bigger spike to make the eye believe it is seeing white? It seems the green is winning for this L4. How do others read the graph? Do the two spikes represent two diffrent phosphors? Dierik

[/ QUOTE ]
The big bump is the phosphor. The blue spike is the LED itself. (White LEDs are phosphors excited by a blue LED.)
 
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Re: SureFire L4 uv-vis microspectrophotometer resu

Here are two more spectrometer results.

This one is a little green. KL4#A00092
A00092.gif

This one is a little purple. KL4#A05277
A05277.gif
 
Re: SureFire L4 uv-vis microspectrophotometer resu

If interested i can post more graphs of an A2 white led and the incan.

-dlee
 
Re: SureFire L4 uv-vis microspectrophotometer resu

Dlee,

Yes, please do the A2. Thanks.

Paul
 
Re: SureFire L4 uv-vis microspectrophotometer resu

So it seems like it's a balancing act between the amount of light escaping from the blue led and the phosphorescene that makes the led appear to be white. It must be difficult to balance these two effects to produce white light. I guess this is why it is such a lottery when you buy one of these lights. What do you think?
 
Re: SureFire L4 uv-vis microspectrophotometer resu

Part of the issue is the balancing act, and part of it is the uneven distribution of wavelengths. I've noticed that the color variance described here -- greenish, bluish and purplish as well as white -- can be seen in mercury vapor lamps also. I've sen blue, white, purplish and greenish ones... in fact, I found one just tonight that had the exact same color as my L4... just a hint of bluish-green.
 
Re: SureFire L4 uv-vis microspectrophotometer resu

If you are referring to the counts measure on the y axis as a measurement of light escaping, please disregard that. The L4 was so bright it easily went off the scale so I had to kinda angle it away from direct exposure to the sensor. Yeah, the counts maximum don't mean nothin' in this case.

-dlee
 
Re: SureFire L4 uv-vis microspectrophotometer resu

Overall though, all these graphs DO look a lot like what LumiLeds claims as an output spectrum for their LS's.
 
Re: SureFire L4 uv-vis microspectrophotometer resu

Here are the A2 white led and incan charts.

White LED's
a2-whiteled.gif


Incan
a2-incan.gif


I'll post more as I acquire more LED lights. Maybe the KL5-8
-dlee
 
Re: SureFire L4 uv-vis microspectrophotometer resu

Interesting, the "white LED's" in the last ones lack the 620nm or so red spike that was present in the Luxeons.
 
Re: SureFire L4 uv-vis microspectrophotometer resu

Nichia white LEDs (which I believe are the kind used in the A2) are known for not having that reddish-orange spike
that Luxeons have.

Here's a spectrum I took of a Nichia NSPW500BS white LED I took with my spectrometer when I first got it.
The "hump" at 700nm can be ignored.

spec6.gif


Note the blue spike around 465nm; this is the actual blue chip that the phosphor is applied to.
I also have a program that gets rid of that 700nm hump, but my spectroscope is now broken, so I can't use it anymore.
 
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