Reflector advancements are dead

[orbital]

+

There seems to be a couple of facts with lights:

1. The light engines will get much more powerful
2. Battery technology will improve

So this leaves the reflector...
The amount that can be changed on reflectors is finite and there are only a few companies trying unique reflector designs.

Have we come to a point where all we'll be getting out of our lights is incremental LUX increase?
Or will topics shift to runtime and efficiency?

 

[scottaw]

I'm waiting for a reflector that you could stretch or something to change the amout of stippling....a real flood to spot change without changing the beam profile. Trust me im working on it....in my head.

 

[Kevin Tan]

The most important element of a reflector is the reflective coating. This coating tech is very costly and is out of most hobbiests hands. And hobbiest is the 1 who pushes the envelope and advances the tech further. As for the geometirc designs, most have been done, in fact what scottaw wants can be done with a bottom OP with gradual smooth surface. BUT the cost of the thing is not insignificant. And nobody wants to stock all the variations of the same reflector with only the diff being percentage of stippling.

 

[woodrow]

I think that the reflector is most likely the hardest part of the light to get just "right" I am sure it requires incredible math and cad skills and simulations...trial and error ect. I remember seeing the first SF reflector 18 years ago and being amazed.

I think that the reflector does make a big difference. The SL SurvivorLED and Heliotek are good examples of this. They seem to illuminate much more than their wattage would indicate they could. Also, as led's change, reflectors must as well. It takes a different reflector to make a Rebel's beam look good than it does that of a Cree.

Just my humble opinions.

 

[lctorana]

"SF reflector"

What's that???

Science Fiction?

Semi Freddo?

Sam Fisher?

 

[Kevin Tan]

Ictorana, a little respect goes a long way. SF in the world of flashaholics is SureFire.

 

[mossyoak]

Ictorana, a little respect goes a long way. SF in the world of flashaholics is SureFire.

And where is he being disrespectful? A little humor goes a long way to.

 

[lctorana]

How is that question disrespectful?

Ignorant, maybe.

People are touchy here. Sigh.

 

[Size15's]

okay, okay lets move on.

 

[PhantomPhoton]

:knight:
Back on topic....
I agree that reflector improvements will have the least impact on how much light we get in comparison to power and emitters. We still have plenty of efficiency to go with LEDs, and who knows how much power density we'll achieve once we start moving to super-capacitors. Decent reflectors right now are ~60-70% efficient, and really good ones I beleive can get up to high 80s. Maybe more... someone with more knowledge will prob chime in.

However reflectors are still a very significant part of the light and must not be ignored. I too am waiting for an electro forming fluid reflector that can change shape or texture to adjust the beam with little to no artifacts, Mag holes, wasted light, etc :crazy:. Now I think that we will see something like this in optics before reflectors. The concept of Fluid lenses has been around for awhile. (Oil lenses in Dune for example) But nonetheless there are some pretty cool things that can still happen IMO.

 

[MikeSalt]

Reflector advancements cannot be dead because they are nowhere near perfect. Typically, torch lumens are 0.65 x bulb lumens. Therefore, 35% of your lumens are wasted. Characteristics of the glass/lexan window can only account for 15% at the most I should imagine, with the reflector causing the other 20% of the losses.

By my reckoning, that makes the reflector approximately 75% efficient. Reflector designers cannot rest until that is as close to 100% as they can make it. At 100% efficiency, the only losses are due to the window, so we would see 85% efficiency overall.

 

[lyyyghtmaster]

I've heard, and roughly verified by testing, that UCL windows with AR coating have only about a few percent insertion loss. Can anyone else chime in on this? Sure the AR is easily damaged, but for non-extreme duty apps, works very well, I think. That pretty much leaves just the reflector to improve for such lights.

 

[MikeSalt]

I would agree with you there, a few percent would be typical. I was quoting worse case scenario. Given the value you quote, that means that reflectors of today are still significantly less than 70% efficient.

 

[yellow]

pffff, ....
still a LONG way to go.

Take any Cree light or insert and compare it with an identical Cree running on exact the same current,
but using a Sandwich Shoppe MxR-XR reflector (19 mm being the best)
what a difference!
if only they did cost what IMS and such cost ...

Dunno on Seouls, there the IMS seem to be not dis of a difference

 

[Gunner12]

Well, RA has made a light with only 3% loss of light. Reflector is 98% reflective and the window transmits 99.3% of the light. Thread here.

Of course, there is the price.

 

[Ra]

Well, RA has made a light with only 3% loss of light. Reflector is 98% reflective and the window transmits 99.3% of the light. Thread here.

Of course, there is the price.

Hi Gunner12,

I must slightly correct you on something:

If you talk about 3% loss of light, it would mean 97% bulblumens are converted into torchlumens.. That is not the case:

The conventional shape of most reflectors causes a loss of bulblumens, which is much more than 3%.. more like 25-35%

The high reflectivity of the reflector in my mini-HID shurely contributes in a better bulblumens-torchlumens ratio, but the most important is the the fact that the high reflectivity preserves the surface brightness of the source. Better throw is the result of that.


As for most efficient reflectors: Few months ago, I made a glass-TIR reflector (Total Internal Reflection) for use with the Seoul SSC P4 emitter..

The theroretics behind it:

Shot at 2007-09-28



A 30mm diameter version I finished earlier:

TIR means 100% reflection inside the reflector (optical fact, law of light). That, with a collimating lens at the center, and high performance coatings, creates a whopping 95% total efficiency. And this indeed does mean converting 95% bulb-(or emitter-) lumens into torchlumens!



I already build a light with a glass-TIR 15.5mm diameter reflector:

When I have the time, I will post a thread on this light in the Custom/modified section of these forums..



Regards,

Ra.

 

[Daekar]

Well then, it sounds like high-performance optics are the way to go, not reflectors, as emitters advance. I wonder why people haven't jumped onto this bandwagon yet... are TIR lenses expensive to manufacture? The difference we're talking about is extreme... sounds like at least a 20% difference in torch lumens to me. I wonder if that's one reason why the L1 is so impressive...?

 

[Ra]

Well then, it sounds like high-performance optics are the way to go, not reflectors, as emitters advance. I wonder why people haven't jumped onto this bandwagon yet... are TIR lenses expensive to manufacture? The difference we're talking about is extreme... sounds like at least a 20% difference in torch lumens to me. I wonder if that's one reason why the L1 is so impressive...?

The TIR-optics used in flashlights by some brands, are acryllic based: More fragile, can easily be damaged, huge thermal expansion. But they are easy to make. (at $3-$6 each)
They have about 90% efficiency, which indeed is much better than conventional reflectors

Glass-based TIR-reflectors are much, much, much harder to make ! I don't know anyone or any brand that makes them.. Do you ??


Edit: Oh.. I forgot: The main reason people are not jumping onto this is the lack of many sizes: The acryllic optics are aviable in only a few small sizes.. Soon, I'll try to make one with a more reasonable 50mm diameter.. Another problem is: Being from massive material, larger diameters TIR's will be heavy!


Regards,

Ra.

 

[gromit]

I'll start out that I'm no expert in optics, but I also have a few nice telescope and know a little about them.

I'm not sure you could get 95% transmission through a mass of glass or acrylic. $7,000 AstroPhysics telescopes are 97% and use very special glass custom ground lenses manufactured to specific light wavelengths. very special coatings to achieve that number. that number is a straight pass through the lenses, not reflected.

I could be wrong I'm not a optical engineer.

 

[Size15's]

The TIR-optics used in flashlights by some brands, are acryllic based: More fragile, can easily be damaged, huge thermal expansion. But they are easy to make. (at $3-$6 each)
They have about 90% efficiency, which indeed is much better than conventional reflectors
Glass-based TIR-reflectors are much, much, much harder to make ! I don't know anyone or any brand that makes them.. Do you ??

I understand that the TIR optics designed by SAIC and SureFire are Cyclo-Olefin Copolymer (example Zeonex) which is a non-acrylic based thermo plastic.

Al