The NX-05 Optics

Can someone explain just how the NX optics work? The other day I was looking at my LS and noticed if I held it at a certain angle,I swear I could see wires and other components in the reflector. The same with my KL1 head, I could almost make out the value of a capacitor. Do these things use reflection/refraction? Does anyone know?

The optics rely on both refraction and reflection. The cylindrical cutout where the LS fits in the optics refracts the light, and the conical outer surface reflects it. Light hitting an interface between two materials of different refractive indices (air and acrylic, for instance) will refract differently depending on the angle of incident light. That's why light "bends" when you look through a fishtank or a drinking glass. If the angle is sharp enough (close to 90 degrees) it will instead bounce with little scatter, which is essentially reflection.

The reason why you can see stuff underneath the optics is because at certain angles it hits the conical surface at a sharp angle, so the light passes through instead of being reflected.

The empirical results of myself and some others suggests that at least the similar though larger Elektrolumens 30mm optics can be slightly improved by ensuring that the conical outer surface does in fact reflect. People have done this by by enclosing it in reflective material or in a reflector. If I had to pick a single number that characterizes the improvement, I'd call it 10%.

My test with chrome paint on acrylic sheet shows that the painted surface looks fairly reflective, while the inside (looking through the acrylic) is a dull gray. Does anyone know of a home-applied paint or process that could be used that would make this type of collimator truly reflective?

My best results have been with:

a) aluminum foil, and
b) reflective white tape

Have not noticed a significant difference between the two. And either one is a lot easier to work with than paints.

If you have access to such equipment, you might be able to vapor plate it. This is how conventional plastic flashlight reflectors are made...though I think they do that to the inside surface, so it is quite possible that you would run into the same problems as with the paint using this method. Worth looking into though. Anything is better than nothing, however!

Anybody try Glow paint on the outside of the optics?

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cave dave said:
Anybody try Glow paint on the outside of the optics?

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Careful, guys! Anyone attempting to coat the outside of the optics with anything - please note that this will alter the refractive/reflective characteristics of the NX05 severely, resulting in at least 50% light loss. (edit: I have used only opaque paints - I have no idea how reflective paints/treatments will fare)

I know it may not seem harmful by merely applying paint on the outside cone, but the NX05 is highly sensitive to almost anything on its external surfaces. From various experiments I have done, I have come to conclude that you actually need *air* (or nothing) around/in contact with the lens cone to ensure proper functioning.

That deceptively simple piece of plastic has some pretty fancy optical fine-tuning built-in! /ubbthreads/images/graemlins/ooo.gif

i second that
I had covering the entire back of my NX05 optic and, guess what, very poor light coming out of the light after that. So sad that even though i tried to clear the back using alchohol, there still some coating there resulting in atleast 25 to 30% loss in brightness. /ubbthreads/images/graemlins/frown.gif

Third that... I tried covering the optics with aluminum foil tape, and it didn't squash out light so much as it did pulverizing the beam quality of the light considerably...

I measired the angle of the "cone" of the -05 on a comparitor at work and got 58deg. I recut one to 64deg and got a "tighter" beam. Hope somebody can confirm.

Larry

Darn! I guestimated that about 10% light loss from the back of the NX-05 and perhaps a bit less on the NX-01 collimator but either way, that's quite a bit of light if I'm right.

Just got a can of shiny chrome paint and turns out that you guys have already tried that. Doesn't work? Has anyone else tried the chrome paint? I'm still going to try it on on collimator but wondering if others have tried it. (And to think I thought this was a fool proof idea....

If that doesn't work, maybe the trick then is to paint the inside of the flashlight head in hope of it bouncing a wee bit of photons back through the collimator and out the front.

Thanks,
Mo

hey, that might work...they won't be collimated but at least it will be light out the business end instead of lost as wasteful and inefficient heat (makes me think of incandescents...*shudder*)

I think I'll just get rid of the anodization on the inside of the flashlight head. Maybe then I'll polish it up nice and shiney. Glad now I didn't modify the back of the optic like I was going to. /ubbthreads/images/graemlins/ohgeez.gif Whew...