Ring around XR-E spots ARE illusions!

Remember that thread where Fenix reps said that the ring found around their XR-E Digital series are just illusions.

It's true! For other XR-E lights which have the "ring" too!

Here's what u do to see that it's actually really just your eyes playin tricks on u.

1. Hold the light in your hand.

2. Point it to the ceiling.

3. Lock your arm and elbow so that your entire arm is stiff against ur torso.

4. Now twist your waist side to side, causing the beam to move across the ceiling. Keep your eyes on the hot spot! Just move your upper body to sway the beam, and keep your eyes fixed on the spot.

5. You will notice that the "ring" now becomes a dark spot which trails the central hotspot!

6. Isn't that the same thing?

7. How come some lights don't have the ring?

8. Why does it show up in pictures if it's an optical illusion and not really there?

9. Why am I numbering this?

10. Are you trying to create an illusion so you don't see the rings, but is really still there?

11. The truth is out there !

You forgot to say "Bloody Mary" three times while spinning around!

the ring is there and it is certainly NOT an illusion. however, it doesn't bother me at all, rather the opposite. it gives me some additional side flood light when my fenix L2D is mounted on my bike's handle bar.


regards, holger

12. The important thing is that the dark ring illusion will disappear if you refocus the beam, and that's why people complain about it, because it doesn't have to be there.

That was ridiculous. Thanks for the laughs though.

The ring probably has the same brightness as the spill. The problem is the green ring (caused by the XR-E metal reflector) around the dark ring that is slightly brighter. It makes the dark ring really apparent!

InfidelCastro said:

6. Isn't that the same thing?

7. How come some lights don't have the ring?

8. Why does it show up in pictures if it's an optical illusion and not really there?

9. Why am I numbering this?

Click to expand...

13. You have to have your left trouser-leg rolled up above the knee when you do this.

LOL - Gets me thinking of those pics that you have to stare at to see the 'real' image (which I can NEVER see.)

x2x3x2 said:

5. You will notice that the "ring" now becomes a dark spot which trails the central hotspot!

Click to expand...

You have just proven the rings really are there! The rings are an artifact of the CREE LED sucking all available light from the area surrounding to feed its hot spot! This is also the reason you see the dark trail following the hot spot. Only it isn't an illusion. It's the result of all the light having been sucked out of the area the hot spot has been over!

I wonder... if you pointed it at the sun long enough, would you get... sunspots?

lol u guys are wierd, im saying its an illusion, yes its there AS PERCIEVED BY HUMAN EYES due to some kinda psychovisual effect.

as u move the light around u will see what i mean, the dark rings shits towards the trailing side of the hotspot.

ill try to use a camera to show it, dunno if it'll show up on a camera tho. check back later.

x2x3x2 said:

the dark rings shits towards the trailing side of the hotspot.

Click to expand...

"shits"

Quick, someone get a mop and bucket and clear up.

Nake said:

"shits"

Click to expand...

I think I've worked out what it is.

it is NOT an illusion.

Taking off reflector on my CREE'd Elly, (though it's the same for any CREE), and focussing beam though a magnifying glass.

What you see, when you focus the multi faceted led, is the background, non illuminating mount, slightly lit by the led, in focus, as a well defined grey circle, around the square led.

As you defocus the beam, the defined led becomes more round, and the defined grey round bit with well defined square led becomes more of the de-focussed grey ring you see around the CREE led.

Go on try it.

You'll see what I mean.

(tried to photograph it, but it didn't really work, due to relative levels of brightness of focussed led and focussed grey surrounding) which both become unfocussed as you move magnifying glass, ie square led becomes round, and well defined grey area becomes a ring.

So the best way for the manufacturer to remove the grey artifact is to make the led lens smaller, or the led larger, or the grey background absolutely non reflective (black).

If you shine another torch into the unlit CREE, you'll see what I mean.

x2x3x2 said:

as u move the light around u will see what i mean, the dark rings shits towards the trailing side of the hotspot.

Click to expand...

That's because you're rotating the torch around a fixed spot, ie your hand, and getting the ring away from the direction of travel narrower, due to geometry.

Similarly, the ring on the leading edge gets larger.

This gives the illusion of trailing.

The bright spot will also appear to move slightly, but less obvious as it is a homogenous? beam

Try moving whole hand, with torch, left and right, and you'll see that you don't get the trailing effect.

That's purely an effect due to greater distance of ring from torch on leading edge as you pan.

If you draw straight lines to spot / ring, simulating your rotational movement, you'll see what I mean.

The leading edge triangle has a longer base line, on the edge away from you...

That's why round spots become elliptical at an angle.

Pan left, stay panned left, and you'll see both the grey ring, and the central spot become elliptical.

Point a lit torch, any torch, straight down, and slowly rotate hand left or right, you'll see what I mean.

Tell me this: If refocusing the reflector gets rid of the dark ring... then... can't you design the reflector around this particular emitter? In other words, 47's says the problem lies with the Cree emitter, but if we can refocus slightly and get the beam to be perfect, why are they not all done this way from the factory? We unscrew 1/2 a turn and the ring disappears. Why not make the reflector 1/2 turn longer and call it a day? Does this sacrifice throw and thus make it look weak on the datasheets?

zeeexsixare said:

Tell me this: If refocusing the reflector gets rid of the dark ring... then... can't you design the reflector around this particular emitter? In other words, 47's says the problem lies with the Cree emitter, but if we can refocus slightly and get the beam to be perfect, why are they not all done this way from the factory? We unscrew 1/2 a turn and the ring disappears. Why not make the reflector 1/2 turn longer and call it a day? Does this sacrifice throw and thus make it look weak on the datasheets?

Click to expand...

It can cover up the grey ring with a very degraded larger bright spot.

Doesn't look very nice at all.

Not pure, very blotchy.

Having said that, my Benno 501B Cree version (DX) (Cree dropin) has a very nice spot, with virtually NO grey ring at all, in quite a tight spot beam.

So it can be done.