SureFire U2 beam

I noticed that my SureFire U2 has some sort of "X" in the hotspot of the beam when shining on a surface from about 1 foot! Is that normal? The "X" appears on all settings and will disappear from more distance.
There is also a narrow dark ring almost at the periphery of the beam!
With my L4 I don't have that "X" and also no dark rings. One other thing I noticed is a spot in the reflector that looks scuffed or scratched. Maybe it's not scuffed but not cleaned very well...? I know this should not affect the beam and is probably just a cosmetic thing. Anyhow, my L4 doesn't have that, its reflector is flawless....
Any ideas what I can do? /ubbthreads/images/graemlins/confused.gif

it's normal.

It must be an "X" bin! /ubbthreads/images/graemlins/wink.gif

*shrug*

I don't notice this on my U2s.

I don't think its normal. Its nothing to worry about (its not IMO an indication that the light is damaged), but IMO its NOT normal.

It's normal.

My L2, L4, and U2 all do this to some extent. On the L's it is more a donut hole, on the U2 more of an "X".

I really don't notice it in everyday use - only when looking for it.

it's normal..

to focus for max throw, it's quite normal to see a hollow spot up close.

Yes, the donut is normal but he is describing an "X" shape. None of my 5-watt Surefires have an "X" shape, to my eyes anyway.

Actually I just looked at all 3 of mine closely and they do indeed all exhibit an "X" shape - the L4 was the hardest to discern but it is definitely there.

I know it's no problem for daily use, I was just concerned why the U2 has it and the L4 not!
One other thing I noticed is a narrow dark ring almost at the periphery of the beam. Does any other U2 have that also? I think it's pretty unusual for SureFires....

mine has it too

Could the charge remaining in the batteries have any bearing on seeing it?

Also, I've noticed being able to see 2 wires on the Ultra G's LED when the battery is almost totally exhausted. I assume that, if the Luxeon's have such wires, that they could be the cause.

I don't see an X with my U2, but it does have a slightly darkened ring around the periphery. I can only see the ring on a white surface. It's not visible to me during normal use.

Just checked mine and it has a very clear "X", but only at 2" on white paper. At 3" the "X" disappears.

Bingo - I can see one on the lowest setting from 2"-7" away from white paper. It looks like a cross with lobed ends.

What you guys are seeing is the emitter itself. If you haven't noticed it is a "+" shape.

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turbodog said:
What you guys are seeing is the emitter itself. If you haven't noticed it is a "+" shape.

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The emitter is actually 4 LED's on a single mount. The X or + is where the joints exist between the individual LED's. That will always exist as no light is produced in this region. Set the U2 on the lowest setting and shine into a monitor screen that has anti-reflective coatings. It will dim the light enough so that you can see the individual LED's in the emitter.

The U2 shows this more than the L4 or L2 as the optics are different. The U2 emitter is recessed much further back than the L4 or L2 lights. This will cause a different pattern.

The X or + is normal and is nothing to be concerned about.

The + is visible at lowest level and only at two inches from the wall. It is the dark area on the die among the four LED chips of the Lux V.
The L4 has a shallower reflector which focuses the beam "before" two inches, thus "masking" the + void. It cannot "mask", however, the the missing portion of a "square to a circle", causing the infamous donut hole. Credits to Don for the last observation, he was the first to point it out.

Anthony

[ QUOTE ]
RayT said:
.... Set the U2 on the lowest setting and shine into a monitor screen that has anti-reflective coatings. It will dim the light enough so that you can see the individual LED's in the emitter.


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Cool!

Here's a shot of my L4. I just noticed this a couple of days ago myself: