Why is this happening?

[Surefire_Rocks]

Huy guys,
First of all, I would like to know why my SF L4 looks like it has a cross in the middle of the beam when put near an object. Also, the light color is white, but very slightly green. Why? Shouldn't it be completely white?
Thanks!

-Ian-

 

[mossyoak]

the reason for the cross is cause of the refector/luxeon relationship it takes a few feet to perfect the beam after it gets out of the head
the reason for the green hint is cause leds come in all colors and they just have to try and get one closest to white people on the forum call it the luxeon lottery its no big deal really

 

[Surefire_Rocks]

Luxeon Lottery?

 

[MrBenchmark]

This artifact, called a "void" or a "donut hole" is a byproduct of the fact that the lux V is really 4 LED's on a single die. There's not much you can do about this. If the void isn't easy to spot at a reasonable usage distance, you are doing well.

The luxeon V LEDs vary in tint. There's not much you can do about this. SF will most likely take the light back if you really complain, but you aren't assured of getting anything better. My advice is for you to use it a while and see if your eye decides that it's white after all. My L2 is slightly greenish on high, and quite greenish on low. The greenish high setting is not bad - I can't really notice it unless I compare it to another light, and even then it's subtle. On low, it's pretty easy to spot. But after using it a while, my eye decided it was white too. (That is, I don't really notice the tint unless I go looking for it.) It impacts the utility of the light not at all. I wouldn't sweat it unless it really bothers you.

Relatively few LEDs are perfectly white. I have an L6 that's pretty close to perfect - got lucky on that one. The luxeon III's tend to be more consistent, but even they have some tint variation.

 

[Surefire_Rocks]

thanks. by the way, how to I reach mcgizomo to get my L4 two-staged?

 

[MrBenchmark]

[ QUOTE ]
Surefire_Rocks said:
Luxeon Lottery?

[/ QUOTE ]

Luxeon I and V LEDs (and to a lesser extent III's) vary across a number of parameters, Voltage Forward, tint, luminosity, etc. They are binned, but this isn't perfect, especially with regards to tint. Thus, the LED you get may vary a bit from someone else who got the exact same light. Hence the term "Luxeon Lottery." Even in the same bin, the tint can vary quite a bit with some of these LEDs.

A lot of people really don't like and do notice the greenish tints. I'm not sure why - but I notice 'em more too. (Whereas my eye just sees the slightly bluish ones as "white," unless I contrast them with another light.) It may have something to do with the fact that our eyes are more sensitive to green light, or perhaps it's just that greenish light sources are rare.

I try to think of my L2 as having a "mint" colored light on low, instead of "rotten cat urine green." "Mint" sounds a whole lot more pleasant - it's like a breath of fresh air everytime I turn my L2 on! Try it - see, don't you feel better already? /ubbthreads/images/graemlins/tongue.gif

Seriously, if the tint of your L4 is bad enough that it affects your ability to discern color properly, you should send it back. Otherwise, I'm not sure I'd bother.

 

[tvodrd]

[ QUOTE ]
Surefire_Rocks said:
thanks. by the way, how to I reach mcgizomo to get my L4 two-staged?

[/ QUOTE ]

You might try the McGizmo board about half way down the main page. /ubbthreads/images/graemlins/grin.gif

Larry

 

[MrBenchmark]

The sandwich shop:
The Shoppe

Sells the 2 stage tailcaps. I believe the ones for the Aleph series are the same as the ones for "E" series lights, but you want Natural HA for the "E" series switch.