# Getting more from our aspheric toys



## ahorton (Apr 15, 2009)

Some of us like to play with aspherics and get nice, tight, long-range beams.

Aspherics cannot collect all the light emitted by an LED, so a lot is usually wasted inside the bodies of our creations. However, there's a bit of technology floating around involving a special reflector to put the wasted light back onto the LED's phosphor which further excites it and increases the surface brightness of the LED. This results in up to a 50% improvement in beam intensity. This is huge! It also lowers the colour temperature of the light emitted by releasing more red from the phosphor.

Sadly, those who have mastered the tech are keeping the secrets to themselves and not making these reflectors easily available to us.

I'm optimistic that we can do some experiments and rediscover some of these tricks. After a quick chat to Troutie, it seemed that he was also interested in working this out and agreed to help do some of the testing.

All ideas are welcome in this thread, but I'll start with the one I've been considering for a little while:

I imagine a plate of aluminium a few mm thick, which has a hole milled into it with a ball nosed endmill. By stopping at the correct depth, this gives a hole with inner walls like like a hemisphere. These walls are polished to a mirror finish. The plate is then inverted and placed between and LED and aspheric lens.

An example of one such setup is shown (crudely) here:









All dimensions are in mm.
This example shows an XM-L LED. At this stage, I don't know how the LED type will affect the design.

I'll define a few terms that may become useful later on:

PT - Plate Thickness
PE - Plate Elevation (above the base of the LED)
PO - Plate Opening
RD - Reflector Diameter

FL - Focal Length

DA - Direct Angle (the maximum angle of the rays which go directly from the LED to the lens)
ELR - Effective Lens Radius (Even though the lens is larger, the edges are not used because the reflector is blocking).

I also want to define a coordinate system with its origin at the centre of the base of the LED.









Finally, we need to be able to talk about:

LS - Light Source, a very simple approximation of where we think the light is effectively coming from. In reality, this is a very tricky concept to nail down but we'll try it simple for now. In the above example, I have put the LS at the origin (y=0 is all we need to say), but it need not be there. We need the LS in order to define the DA and PO which are all connected.

RC - Reflector Centre, the point at the centre of the sphere which defines the shape of our reflector. In the example above I have made it the origin. I suspect this will end up the same as the LS.

A simple test-rig could involve an LED on an MCPCB, held onto a heatsink with 2 screws. If two holes are drilled in the reflector plate, then the screws can pass through the plate, through some spacer washers (PE thick), through the MCPCB and into the heatsink. This will hold the MCPCB down and also allow fine adjustments of LE with thin enough washers.

A short explanation of why I chose some of the parameters in the above example.

RD - 10mm easily clear all the LEDs I know of, but is also small enough to fit in most applications.
DA - 41.14 degrees. Any larger and the light is reflected off the back of the lens anyway (BK7 lens - index of refraction =1.52). That's the theory anyway. It will be interesting to test it.
FL - 11mm. This is what I usually use with my XR-Es and XP-Cs. I think it's the same witht the XM-L but I don't use it much.
PD - 3mm. Any thicker would have no effect. Much thinner and you can't get the full reflector (assuming RD and DA).


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## Goldigger (Nov 6, 2009)

Interesting idea..
Might be worth taking a reflector and chopping it down in height, then put it over the led upside down?
Then you can test yout concept without a load of machining..
I might even try it myself later...

Reminds me of this concept used in dive lights..
They put a led into a test tube rather than a hid bulb and made a reflective coating at the at inside..


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## Goldigger (Nov 6, 2009)

Maybe this concept might work?


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## BKruahnndon (Jul 17, 2009)

wish i was a bit more advanced in optics and lighting so i could help out more. this is something that really interests me! Anything I can do to help, keep me posted.


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## BrianMc (Jan 5, 2010)

Timely. Santa is helping me upgrade my aspheric helmet light. I send a portion of wide angle light off one LED to be caught by amber side hoods for side visibility. The rest bounce up the light tube to the lens or are absorbed.

BrianMc


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## emu26 (Jun 23, 2008)

Subscribed.

How do you know that it is light reflected back onto the LED that then excites it and helps generate more light or a warmer hue as opposed to just redirecting the wasted spill light back onto the aspheric by say, using a cut down reflector to fill the void greated by the FL of the aspheric? I would have pictured using a reflector with a smaller diameter than the base of the aspheric to help focus the light prior to it hitting the aspheric.

This will be very interesting.

Well done


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## ahorton (Apr 15, 2009)

Great to see some interest already!

Golddigger, cutting down a reflector is exactly what I want to do, but I haven't found a spherical one with diameter 10mm or less. All I can find are parabolic ones. I want something that will return a ray to the point from which it came. parabolic ones take diverging rays from a point and redirect them to leave the reflector in parallel.

What am I looking at in your second picture? I can't quite work out what it is or how it will help.

emu, I can see what you're suggesting, but unfortunately we can't use a reflector to direct light towards the lens. The lens only collimates light coming from a point source. The reflector will have already collimated the light and sent it forward in roughly parallel rays. The parallel rays hit the lens, converge and then diverge to create a very wide beam. 

What you end up seeing when you put an aspheric over a reflector, is a very enlarged image of your reflector surface. You can see very clearly every speck of dust, fingerprint or hair which is near the focal point. It's interesting, but not what we want.

We only want rays hitting the lens if they have come from very close to the point source. Our source isn't really a point, it's a square die, but that's good too because we do want a little bit of spread. Otherwise our beam would be infinitely narrow and you couldn't see anything.

So my thinking, is that for any particulr ray of light leaving the LED:

1. if it is going directly towards the useable region of the lens, then we should let it reach the lens and be directed forwards to illuminate some object far away for us to see.
2. if it is not going to reach the useable region of the lens, then we should direct it back towards the source. Here it will either:
a, be absorbed in some form and not produce any more light. In this case it is lost.
b, be reflected in possibly many angles, making it a bundle of rays which are leaving from the LED (go back to point 1).
c, excite the phosphor and cause it to release light which leaves the LED (go back to point 1).


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## BrianMc (Jan 5, 2010)

^ Yes, very interesting. Have to work up my parts order. I played with crudely reflecting the light out the aspheric and got rings, so the right curve might be hard. I think the reflect back on the die is intriguing. Maybe that is what the ring on the XR-Es does, in part. They are very narrow, of course the small die helps.

An XP-E R3, XPG S-2, and XM-L U2 could stand to be warmer, but how warm does a thrower need to be? It will be interesting to try the technique on the three different LEDs in the same light with a much smaller (12.7 mm diametger) aspheric lens. Three different RDs and PTs for the three die sizes and dome heights? Any recouping lost light will be better and reduce the fuzziness of the die projections I have now. 

BrianMc


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## troutie-mtb (Sep 20, 2007)

This is an interesting one Thanks Ash for the thread

Been thinking and googling about this one since your mails and it does appear to be a genuine phenomenon with little info about on the web is it a new discovery ?.
see Wavien, Inc. not a lot to go on

and see also Groundbreaking New Thrower!!The new DEFT-edc LR

Saabluster is well known for squeezing those lumens from a Led but as usual and understandabley is not telling too much about the technology .

OK lets look at how 
the easy way would be to buy one of Saablusters lights and have a look .

Or as Ash pointed out to me in his mails maxe a collar or 3 and do some testing this will entail some pretty small machining and polishing which I see as a real challenge

then there is the testing 50% brighter thats a huge amount but the eyes are not too good at seeing those improvements .

I have ideas on making the collars its the polishing that eludes me at the moment

one other question for you Ash is the collar also reflecting back heat into the die


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## sergio_pt (Jan 29, 2007)

Ok sounds interesting. 
But first how is a extremely excited phosphor is going to be even 50% more excited? 
Isn't that the same as giving the LED more power? Reducing the LED life span, overheating and burning? Maybe that's why the color gets more warmer, it's because the phosphor is burning. 
When you redirect the rays back to the substrate I Imagine that is what is going to happen...overexciting, overheating, overburning, 
Am I missing something?
Do you have references?


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## ahorton (Apr 15, 2009)

BrianMc, you're right that a thrower doesn't need to be very warm. I'm told it helps a little with visibility if our eyes can pick up the colours better but I doubt it's a huge effect.

Troutie, I think the polishing won't be too much of a challenge. I usually do it by starting with some fine grit wet paper and working up to a cloth wheel on an orbital tool with various cutting compounds. This is not going to produce the same mirror surface that vacuum deposited silver on glass will, but I think it will be pretty good. I'm also hoping that we can come up with a method that is easy enough for us hobbyists to recreate in our own sheds. Later on, who knows, maybe we can find a professional to make us a beautiful silver reflector to our exact specs. If we make a few thousand then they'll come out pretty cheap. 

At this point I'm just hoping to test the idea. If we can make a very crude reflector and get a 15% improvement in the beam, then we'll know that we're onto something.

As for the heat being reflected back to the die... yes... sort of. The radiant heat will be reflected back. However I'm not too worried about this. Firstly because there is not much radiant heat coming forward from the LED and secondly because that heat would have been absorbed inside the housing anyway (though admittedly not back into the LED itself). I realise that when you put your hand infront of a high power LED you can feel the heat, but this is not actually all radiant heat energy. Most of it is light energy which is being absorbed by your hand and converted into heat.

Sergio, I'm not sure how excited the phosphor already is. There is a saturation point but I don't know how close we are to it. So I can't comment yet. In anycase, we don't need the phosphor to be giving off 50% more light in order to get a 50% increase in the beam.

As I understand it, Our white LEDs produce light in the blue-UV end of the spectrum. Some of this gets through and some of it excites the electrons in the phosphor layer. As the elctrons drop back down they give off a bit of red light. The mix comes out as various whites. So we'll be reflecting a whole range of frequencies back to the LED. Some of these will excite the phospher to give off more red. Others will be refracted and reflected in the different mediums of the LED. I expect a fair bit of scattering and I won't pretend to calculate the paths of a ray going in and out of the LED, but I hope to control its exit. If it exits towards the lens then we let it go. If it goes in a different direction, then we want to reflect it back at the LED for another shot.

Will this damage the LED? I don't think so, others are using it, but I'm keen to find out. Suppose the LED was originally good for 10K hours and we reduce that to 2K hours by overworking it. This is a pretty severe reduction, but you'd still get a 3 hour ride everyday for a two years out of it. Even then it wouldn't be dead, it'd just be a little dimmer.

...and if we discover that it does destroy the LED, then at least we'll know something that the guys using the tech haven't told us.


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## mrradlos (Sep 3, 2010)

Ahorten that is a very interesting idea. I have been playing with your aspheric lens and your lens kit with the XM-L. For me they provide a much better light for mountainbiking than spotty TIR-lenses or reflectors, because those have a too bright hot spot, when used as single emitter lights.

The kit you used to sell (sold out I think ?) for torch drop-ins, are not suitable for mountainbiking, because those drop ins-don't have enough thermal contact to the torch body and therefore get dimmer quite quickly even on downhills in freezing nights.

I have tried to put two XM-L touching each other behind an aspheric lens in a easy2led housing. But even with defocusing them quite a bit, the two spots were too far apart for a bike light.

Would it not be much easier to pull the dome off the emitter and send all the light directly to the lens? Might have to take a bigger emitter like the SST-90?


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## ahorton (Apr 15, 2009)

As it turns out, you need the dome to get the light out of the LED package. Without it, you sacrifice a lot of light to internal reflection. Imagine a point source of light inside a glass cube. Light only escapes inside a circle on each face. At the corners the angle is too great. Inside a glass sphere however, the light can escape at any angle.

Dedoming can give you a smaller effective light source and this makes for better throw, but you get a much more narrow beam. Personally, I don't think it's worth doing. You get less total flux coming out of the LED and a bigger portion of it goes sideways away from the lens.

As for the kit, I have a couple left, but not many. You are right that they're not great for high power LEDs like the XM-L or SSTs. They were made more for the XR-E.

Also, as a rule, you can never put two light sources behind a single aspheric. It'll always be ugly. Even using multi-die LEDs like the MC-E or SSC-P7 gave ugly beams. The lens gives you an image of the light source.

Glad you liked the lens otherwise!


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## bumphumper (Jan 8, 2009)

Been thinking about this whilst at work......could the lens of the led be partially painted to achieve the same effect? (will be easier to do with an xml than an xpe!) 

Maybe dip the top of the dome in an easily peelable glue, paint dome, then peel off to allow light to escape.

What do you think?


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## ahorton (Apr 15, 2009)

I had considered the same thing, but I never found a paint that promised high enough mirror efficiency. My plan was to encase an LED in an RTV silicone, then cut the LED out in such a way that I'd end up with a silicone jig that gently holds a LED in place whole covering the base and cap.


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## mrradlos (Sep 3, 2010)

ahorton said:


> 1. As it turns out, you need the dome to get the light out of the LED package. Without it, you sacrifice a lot of light to internal reflection. Imagine a point source of light inside a glass cube. Light only escapes inside a circle on each face. At the corners the angle is too great. Inside a glass sphere however, the light can escape at any angle.
> 
> 2. Dedoming can give you a smaller effective light source and this makes for better throw, but you get a much more narrow beam. Personally, I don't think it's worth doing. You get less total flux coming out of the LED and a bigger portion of it goes sideways away from the lens.
> 
> Glad you liked the lens otherwise!


Yes, the lens is really nice!

1. Do you mean the light sort of comes from one point underneath the phosphorus square and reflects already at the flat surface? Well, the flat side from the dome above can't prevent that can it?
Well thinking of it, the blue light from the emitter under the phosphor layer must partly go through phosphor in different angles (0-180°). Part of the blue light activates the phosphor, witch emtits light of a different color (yellowish?) in every direction (360°). Part of this light blue and yeollowish will be reflected back at the phosphor-air boundary of a dedomed led, but might not be reflected at the phosphor-dome boundary?!
I always thought, the dome was there to spread the light a bit, for example viewing angle for the XM-l being 125°. While according to your drawing your lens can only use 2x41°.

2. According to what I read dedoming really gives a smaller effective light source (and this makes for better throw). But should it not get bigger, if the reflecting angle gets bigger at the phosphor-air boundary. You also said more light goes sideways. I still didn't get that right :madman:


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## mrradlos (Sep 3, 2010)

bumphumper said:


> Been thinking about this whilst at work......could the lens of the led be partially painted to achieve the same effect? (will be easier to do with an xml than an xpe!)
> 
> Maybe dip the top of the dome in an easily peelable glue, paint dome, then peel off to allow light to escape.
> 
> What do you think?


That sounds much easier than building and polishing a tiny reflector. What colors do they use to make the small plastic reflectors of the cheap bicycle-lights? That should be good enough, even though I noticed a lot of light goes through these plastic reflectors. The color has to handle high temperatures well.


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## bumphumper (Jan 8, 2009)

Yes, see what you mean- just painted some silver conductive paint onto some glass and from below it isn't silver or reflective (unlike the top surface).
A couple of other ideas:

Silver/gold leaf?

Use a substance on part of the led dome to create TIR - (saw the fishtank in the works reception area and thought of this one! Been doing a lot of day-dreaming at work today!)
Will read up on this to see if I can understand how to create this effect, as its been a long time since school physics.


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## BrianMc (Jan 5, 2010)

I dedomed an XP-G to get more throw. It changed color over time and appeared to lose output as an XP-E R3 outdid the dedomed R5. I left some matrix above the phosphor, but maybe oxygen got through enough over time to reduce the phosphor output. It was worth a shot, but I won't go that route again. 

With a 12 mm lens and a 6 mm FL, the percent of light getting lost is significant. Just begs for this treatment. Reading Saabluster's thread suggests he modded the LED, and hat may be ideal, but a DIYer solution is still a good goal.

BrianMc


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## Goldigger (Nov 6, 2009)

Watch the little flash player movie at the top of the screen on this page..
Welcome To Premienled.com

That looks like "your" idea Ahorton..

Also discussed here
Anything out ther brighter at a distance than our flashlight? - Page 2


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## mrradlos (Sep 3, 2010)

You might find a little concave mirror here, to drill a hole in.


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## ahorton (Apr 15, 2009)

Golddigger, I don't think I ever claimed it as my idea. I just want to learn how to use it.

mrradlos, we need more than just a concave mirror. Let us know if you find a spherical one under 15mm diameter.

I might have another shot at the mirror chrome paints. Can anyone suggest a good one? I suspect I'll be limited by what I can find locally.


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## troutie-mtb (Sep 20, 2007)

OK in true Troutie style a little experimenting with bits that are to hand 
I dont think I have ever made something so small on the mill and got a nice polish on it too



















I have no measuring method other than to do a before and after pic on the ceiling with the camera set on manual coming soon


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## troutie-mtb (Sep 20, 2007)

Food for thought

no collar









collar


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## bumphumper (Jan 8, 2009)

Well, I think that works!!!!


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## Toaster79 (Apr 5, 2010)

Looks like the collar is cutting off chromatic aberration of LED's lens, so there is no color shift on the edges giving you bigger hot spot.


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## troutie-mtb (Sep 20, 2007)

I think I now need some pointers from Ash for future experiments ref sizing and positioning

I have made a more repeatable test rig so I can get the lens in the same position every time I make an amendment 
click on the pic


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## CSonmor (Apr 22, 2009)

*Why light color affects beam throw*

I've been lurking on this site a long time, and seen many discussions about beam throw, and haven't seen this point raised; I apologize if this is a repeat. I read a very technical article many years ago (negatively) comparing HID car headlights to the halogen headlights available then. I will try and paraphrase because I can't find the article any more.

*The premise:* the bluish HID beam would scatter more quickly than the yellowish halogen beam, making it unuseable for drivers on unlit rural roads.

*The science:* Light travels as a wave, and every different color of light has a different wavelength. These range from infrared, with a very long (low frequency) wavelength, to ultraviolet, with a much shorter (higher frequency) wavelength. Every time a wave changes direction it loses some energy. Therefore, having 2 light beams of equal energy, the light with a shorter (cooler) wavelength will change direction more often, and hence will peter out more quickly than its longer (warmer) counterpart.

We are surrounded by examples of this. Why does the sun appear yellow, it is much hotter than a yellow flame?

Sound waves work the same way. The next time your neighborhood teenager passes by, reflect on the fact that you can hear his subwoofer (long wavelength) way before you see him, but his tweeter only screams at you while he's right in front of you.

Hope this sheds some light on this topic. 

Chris


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## Goldigger (Nov 6, 2009)

I zoomed that image on my phone so i could just see the white square, it doesn't appear any brighter to be honest..

I don't think the original comparisons between the two deft torches are equal..
The warmer tint appears brighter..
I notice this when I dive, halogen lights appear brighter because of the warmth of the colour..
Compare that to a white led beam or a hid that's blue in colour.. hide have great narrow penetrating beams, so they throw further.
But the halogen with its orange colour is more visible, giving it an illusion of being brighter..
But the halogen lights never throw as far as the hids..due to the difference in the way the bulbs are constructed, the hid bulbs lend them self better to reflectors.
I think this is the same as to the new deft appearing brighter than the old white led..
Just my opinion


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## The Understater (May 6, 2007)

*Polishing.*

Troutie you mentioned not being too sure about how to polish the reflectors. The easiest way to polish it up would be to lap it using some form of paste polish or even jewellers rouge on a hardwood lap. You could do several grades to get a really high level of shine, but actually I reckon you could get away with using Autosol for pretty much the whole thing.

Just turn up a small piece of wood in the lathe to get the profile you want... ie match the profile of the reflector. Hard woods are best. Rose or apple are recommended for making laps, but to be honest, and especially considering we are only talking aluminum here, you could use pretty much anything. Rub a bit of autosol or other polish on the lap, push it into the reflector and turn. I would do it in the lathe or mill myself. Make the lap first and then move it to the tailstock. Turn up the reflector and then bring the tailstock up... I think you get the picture. It's a good idea to use some way cover cloths if you're using polish anywhere near your lathe.

Hope this gives you some ideas.

b.


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## brad72 (Jun 12, 2009)

If you check out the module in this link Order LED Kit the reclaimer is an expensive little bugger and it look like they have spent a lot of dollars on R&D getting the radius's just right.

I'll have to dig up the formula we used to use for mirroring glass as might be useful to get the best reflection fro the aluminium.

The only aspheric I have is 80mm diameter so probably too big but has anyone tried using a high efficiency collimating lens to capture the wasted light before sending it through the aspheric or does this not work? I would assume that as long as the focal distance and diameter of the aspheric is correct for the chosen collimator it should work

anyway interesting thread


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## ahorton (Apr 15, 2009)

Woohoo! Some results!

I tried to do some analysis on the images, but the centres are both saturated, so it's not possible to calculate which is brighter. Any chance of a shorter exposure?

Have you tried elevating it? If you cut a pile of thin washers (paper or card are probably easiest at this point) you could slowly raise the reflector (taking pictures along the way). Let me know the exact dimensions (plate thickness, opening and reflector diamater) of what you've made and I'll calculate what I think the optimal elevation will be. Of course the calculation is just to see if my assumptions are valid. The experimental results are what we actually care about.

It sounds like you're pleased with the mirror surface so far, hopefully you can use some of the suggestions that others have made too. I like how small it looks on the XM-L star.

brad, I think a lot of their sample cost is the big LED. What they show is also too big for us to use easily with these 27mm lenses. With an 80mm diameter lens it might be ok.

As for using multiple lenses, it has certainly been done before. You can get very good results, but the complexity of the system goes through the roof. I found that with one lens I only need to be within 0.5mm of the perfect focal length to get reasonable results. This is a very wide range so it's not too hard to make something that works. Add a second lens and suddenly the system is extremely sensitive. While it is possible to get better results, a tiny movement of either lens throws the whole thing out and it's worse than it was with only one lens. Even when it is working well, a lot of light is still wasted to reflections off the back of the pre collimating lens.

The early DEFTs used dual lenses, but they were abandoned when the type of reflector we're working on here became popular.


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## troutie-mtb (Sep 20, 2007)

yes its very early days and it would have been amazing if good results had come from the first stab.

very rough measures here 

its made with a 6 mm ball nosed mill and a very old one at that .

my thoughts were to start with a 5 mm ball nosed and go up from there so have a carbide one on the way 

will redo the pics and under expose them next 

my dremel died a while ago but i suspect santa has one for my as was forbidden to get a replacement


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## troutie-mtb (Sep 20, 2007)

new photos

collar









no collar


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## ahorton (Apr 15, 2009)

Hmm. No obvious increase in intensity, but I do sense a slightly warmer tint.

What is the diameter of the opening (smaller part of the hole) and what is the thickness of the plate?
I'm guessing that the plate is sitting directly on the MCPCB as you showed earlier.

What size ball nosed mills do you have (either now or on the way)? Just so we can try to keep our ideas within the limits of the tools you have.


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## troutie-mtb (Sep 20, 2007)

ahorton said:


> Hmm. No obvious increase in intensity, but I do sense a slightly warmer tint.
> 
> What is the diameter of the opening (smaller part of the hole) and what is the thickness of the plate?
> I'm guessing that the plate is sitting directly on the MCPCB as you showed earlier.
> ...


The Aperture is 4 mm dia 
plate thickness is 2 mm but it is sitting on the star so only 1.2 mm thick .

my only other ball nosed is a 10 mm at the moment and a rather crappy 12 mm


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## emu26 (Jun 23, 2008)

Troutie, how close in time to turning the LED on were the pics taken? I ask because would it not take time for the "bounced back" rays to excite the phosphor?


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## ahorton (Apr 15, 2009)

No, it'll be instant to our eyes.


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## troutie-mtb (Sep 20, 2007)

Ash going off your diagram what sized aperture would be required for the collar 
if it was sat as close to the led dome as possible 

so when my 5 mm mill arrives 

from my rough measures the dome is 2.2 mm high and 4.46 dia 
so I mill out a dome at 2.5 mm high and 5 mm dia and then mill off the top to get the aperture that you calculate


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## ahorton (Apr 15, 2009)

troutie-mtb said:


> The Aperture is 4 mm dia
> plate thickness is 2 mm but it is sitting on the star so only 1.2 mm thick .
> 
> my only other ball nosed is a 10 mm at the moment and a rather crappy 12 mm


Based on this info, I estimate that the reflector you've made will need to be raised by 1.05mm above the star. That's my guess anyway. Anything from 0.8-1.3mm would not surprise me if it gave better results. I suspect it'll be fairly sensitive to elevation which will be a pain during testing.


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## ahorton (Apr 15, 2009)

For the 5mm mill reflector, you'll want to mill 0.62mm off the dome in order to get a 3.3mm aperture. At this stage, I'd err on the side of a bigger apperture if necessary. This will make sure we're not blocking any light going directly to the lens.

You'll end up with a plate thickness of 1.88mm and I expect it'll need to be raised off the star by 0.9mm. Anything from 0.7-1.1mm would not surprise me. 

I suppose it wouldn't be hard to start with a thicker plate and build this elevation into it by milling the dome an extra 0.9mm deep and then milling out a larger square or circle 0.9mm deep to allow for the LED's base and avoid any solder pads on the star. For now I think it's better to do the elevation with washers or other spacers so that we can get it just right.


If the 5mm works well, then that'll be great. Nice and small!


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## Goldigger (Nov 6, 2009)

Maybe a lux meter might give better testing than camera shots..


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## troutie-mtb (Sep 20, 2007)

Goldigger said:


> Maybe a lux meter might give better testing than camera shots..


i am not spending on a meter till i see a difference :nono:


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## Goldigger (Nov 6, 2009)

troutie-mtb said:


> i am not spending on a meter till i see a difference :nono:


I wasnt suggesting you should or even an exspensive one..
Maybe the people who are serious about this experiment could all put a few of £/$ into your paypal account and raise funds for one??

Think of it as a xmas present for your effort and time and contribution to the board..
Maybe something like this
Professional Light Meter 400,000 LUX UK SELLER | eBay


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## ahorton (Apr 15, 2009)

At this point the photos certainly give us enough info. It's not making an improvement yet.

If the difference isn't visible to the eye or in a photo then it's not worth the effort. Once we get to the point of fine tuning, then we can worry about a lux meter. In that case I'm happy to buy a few reflectors and do more tests.

Collar is on the left.









Interesting that one side of the projected image is brighter in both. Shows great consistency in Troutie's photography.


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## Goldigger (Nov 6, 2009)

Here's the doc for the Waiven patent..
Diagrams are also on there showing how it all works..
Patent US6840623 - Light recovery for projection displays - Google Patents

And another, but not waiven
Patent US20070291491 - Illumination system and method for ... - Google Patents


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## Goldigger (Nov 6, 2009)

Chris have you got any dedomed leds I'm wondering if leds with domes dont work with this idea,
Wavien are using the CBT-90 led which is domeless.. (smd?)
Any idea whats in the deft?









This image was posted by saabluster, looks like it may be the same led?
This was using one of the light recycling collars and without..


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## ahorton (Apr 15, 2009)

Goldigger said:


> Chris have you got any dedomed leds I'm wondering if leds with domes dont work with this idea,


It's possible, but for reasons already discussed (plus simplicity), I think we want to stick with standard LEDs. The company you mentioned have claimed (in emails to me) to have used their techniques for all our favorite Cree LEDs, but seem unwilling to sell me either products or licenses.



Goldigger said:


> Any idea whats in the d**t?


It uses an overdriven Cree XP-C which is kept cool by using an excellent thermal path. We can test that at some stage.

Just so you know, I'm trying not to use the actual names of the these guys who have mastered the technology already. This is largely out of respect. I would prefer somone searching the internet to find their websites rather than a thread in which we try to uncover their secrets.

In terms of pragmatics, I don't think there's much useful info to be obtained through any of the links to their advertising or patents. Troutie in his experiment has already surpassed all the information I've been able to uncover from these sources.


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## Goldigger (Nov 6, 2009)

ahorton said:


> It's possible, but for reasons already discussed (plus simplicity), I think we want to stick with standard LEDs. The company you mentioned have claimed (in emails to me) to have used their techniques for all our favorite Cree LEDs, but seem unwilling to sell me either products or licenses.
> 
> It uses an overdriven Cree XP-C which is kept cool by using an excellent thermal path. We can test that at some stage.
> 
> ...


Am i not free to post what i think may be usefull??
If you personally dont find it usefull then dont read it, others may find it of some interest.


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## brad72 (Jun 12, 2009)

After some reading I now understand that the wavien collar actually re-routes the spilt light back into the led dome and therefore contributes to the increase in brightness. You can't capture the lost spill and direct it to the aspheric because the focal point is that of the led die so regular lens' and collimators will do nothing.

Ahorton I though a nice test rig would be to us the mill . The led die+heatsink could be held in the vice with the aspheric mounted at its focal point. The wavien collar would be mounted to the z-axis head. This means the x axis cross slide could be slowly moved back and forth thereby changing the distance of the wavien collar form the die but more importantly making the process repeatable and the measurement would be seen on the mills dro.

Thinking out loud I wonder how the lambertian leds would go and whether a cylindrical collar would send the light back to the centre to be focused by the aspheric.


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## BrianMc (Jan 5, 2010)

brad72 said:


> Thinking out loud I wonder how the lambertian leds would go and whether a cylindrical collar would send the light back to the centre to be focused by the aspheric.


I got a fuzzier die image but a brighter one by not painting the insides of the brass tubes holding aspheric lenses. So that technique works to a degree. It is possible that some angles get reflected back at the die. Some bounce with decreasing power on each reflection until they are not much help or absorbed others make one bounce and out the lens. I did not polish the tubes to mirror finish and they have likely tarnished in the heat of the light.

BrianMc


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## brad72 (Jun 12, 2009)

Guys have you tried taking the reflector off an XRE and slipping it over the dome of the XML? I would give it a go but have none in my box of bits. Presumably they added the reflector the XRE to improve the lumen output.


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## ahorton (Apr 15, 2009)

You can make it work as a reflector for pushing the light forward, but it's the wrong shape for reflecting light back to the die (even if you turn it upside down).

They are not used to increase the lumen output (infact any reflective surface is less than perfect so they actually decrease the total flux). What they do is change the shape of the beam from very wide into a more useful and directional beam.


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## brad72 (Jun 12, 2009)

ahorton said:


> You can make it work as a reflector for pushing the light forward, but it's the wrong shape for reflecting light back to the die (even if you turn it upside down).
> 
> They are not used to increase the lumen output (infact any reflective surface is less than perfect so they actually decrease the total flux). What they do is change the shape of the beam from very wide into a more useful and directional beam.


Thanks for that. You learn something new everyday.


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## troutie-mtb (Sep 20, 2007)

I am still messing around with no good results to report yet 
damn cutter not yet arrived must have got mixed up with santas stuff in the mail.:madman:

Made a tiny collar last night all polished to a mirror and while cutting it off the piece of stock 
I had it in my fingers and next thing it was gone cant find the little bugger anywhere


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## brad72 (Jun 12, 2009)

troutie-mtb said:


> I am still messing around with no good results to report yet
> damn cutter not yet arrived must have got mixed up with santas stuff in the mail.:madman:
> 
> Made a tiny collar last night all polished to a mirror and while cutting it off the piece of stock
> I had it in my fingers and next thing it was gone cant find the little bugger anywhere


Curses on both accounts. Did you use a ball end mill or cut a form tool ?

I lost a sump plug one day and found it 6 years later wedged between a brake hose and wheel arch.


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## ahorton (Apr 15, 2009)

hmm.. not such a good result then.

Hopefully the new tool will arrive sometime and we'll have new results after Christmas.

Can I assume that the first collar didn't give any better results with extra elevation?

How has the polishing gone? Are you happy with your results? Is it getting easier?


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## troutie-mtb (Sep 20, 2007)

ahorton said:


> hmm.. not such a good result then.
> 
> Hopefully the new tool will arrive sometime and we'll have new results after Christmas.
> 
> ...


Lost the first collar too 
tried a few incarnations using tool I have. all to no avail

this last one was a nearly prefect fit on the dome i was looking forward to trying it out 
then poof gone

polishing is the easy bit and will get easier if the box under the xmas tree is what i think it is.


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## ahorton (Apr 15, 2009)

One lost collar.
A second lost collar.
A new tool not arriving.

...gentlemen, we are dealing with dark and sinister forces here. These things were never meant to be.

I just pray that Troutie makes it through Christmas...


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## troutie-mtb (Sep 20, 2007)

ahorton said:


> One lost collar.
> A second lost collar.
> A new tool not arriving.
> 
> ...


It will be Waivien with a voodoo doll of a trout we must be getting close to the holy grail

5 mm carbide 5 mm ballnosed mill is still in Germany so not much chance of getting quick 
now


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## troutie-mtb (Sep 20, 2007)

OK mark two of the lost collar

with collar









without collar


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## JezV (Oct 31, 2009)

Well, the circular 'ring' is more pronounced with the collar so it's doing something, but I couldn't say for sure whether it's any brighter in the middle


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## troutie-mtb (Sep 20, 2007)

Made a small .5mm increase in the collar aperture 
and zoomed in I reckon its time for a lux meter


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## bumphumper (Jan 8, 2009)

I still think that the image in post 24 with the collar has a much warmer tint, thats why I got all over excited (like the phosphor!) but the later images dont seem to have such an obvious colour change 

Just as an experiment, would it be possible to shine the light from an xpe/g through an aspheric onto the xml die, to see if this has a noticable effect on the xml phosphor output? 

Keep up the good work!!


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## JezV (Oct 31, 2009)

Aah, I can see now. That'll be 'washed leather' pattern to your artex then! A British classic.


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## brad72 (Jun 12, 2009)

Chris i must be spoilt having a tooling shop 5 minutes down the road from work. I had a play with collars (fiddly little things)and the 80mm aspheric I have last night but I need to make my aperture much bigger as I am loosing light. Like you have observed however there is a definite difference in the intensity but yes it needs to be aimed at a lux meter. 

My poor dog (a kelpie) was going insane because she loves to chase lights and I was fiddling for about a hour 

Time to get some 27mm aspherics from Ash


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## ahorton (Apr 15, 2009)

Looking Good Troutie.
I think it is a little bit warmer and brighter.

bumphumper, Interesting experiment. I may try it at some point, though I expect that the extra light being introduced might confuse the results.

brad, your lenses are packaged up and will be in the post very soon. What are the dimensions of the collars you are testing? I'd love to hear more about your tests.


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## brad72 (Jun 12, 2009)

Ash I don't know if I can do any more testing because of the voodoo involved. The rear cap of my new housing vanished last night and I can't find it anywhere. Being bright red isn't exactly inconspicuous so I can only put it down to Wavien VOOODOOOO.

I have done collars very similar to Chris but with the 80mm aspheric they need to be bigger. Once the smaller ones arrive it should be easier. I'm going to sharpen up a form tool as see how that goes.


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## ahorton (Apr 15, 2009)

What is the focal length of the 80mm aspheric you're using? I'll be very surprised if it's got a smaller focal length / diameter ratio than the little 27mm lenses. Even if it does, the limiting factor is still the 41 degree beam before reflection becomes dominant.

If I'm right and the ratio is larger, then the collar shouldn't need to be any bigger. If anything, the aperture should be smaller since the lens uses a more narrow beam directly from the LED.

I'll spare the maths, but unless the distance from the LED base (top of MCPCB) to the flat back of your 80mm lens is less than 43.5mm, you'll want a smaller aperture than when you use the 27mm lenses. This is assuming it's some kind of glass with refractive index around 1.5-1.6.

My understanding is that the size of the collar will be more related to the LED than the lens. Only the aperture will be dependant on the lens's focal length. Of course, if the lens has such a long focal length that a smaller aperture in the reflector is helpful, then the lens is sub-par for our uses.


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## Goldigger (Nov 6, 2009)

I used your images Chris and made them into a gif so its easier to see the difference..
looks like you might have done it..


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## brad72 (Jun 12, 2009)

:thumbsupefinitely brighter with the collar:thumbsup:


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## troutie-mtb (Sep 20, 2007)

Thanks Jay for the Gif :thumbsup:

Last experiment before christmas 
I thought from seeing Jays presentation of the pics some realtime beamshots were needed to see if it shows in the wild.

the setup in the rear of my van 









2 amps no collar









2 amps with collar









3 amps no collar 









3 amps with collar









Now waits for Jay to Gif them


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## Goldigger (Nov 6, 2009)

Here's the gifs..
2amps








3amps


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## JezV (Oct 31, 2009)

Well, that looks like a big thumbs up to me. The collar seems to reduce spill and either brighten the hotspot. Also, the colour looks a little warmer. Well done Troutie and Ahorton, and thanks Goldigger for the GIFs.

Have a great Christmas guys, I hope those boxes under the tree contain new CNC lathes, milling machines, polishers, ano kits and all the other toys we all dream of


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## troutie-mtb (Sep 20, 2007)

Thanks Jay your a star .

Well that looks like things are possible looking forward to getting back in my garage after christmas for some more playing around .

I must admit when I saw the photos I was doubtful of any differences 

but the Gifs tell it how it is


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## ahorton (Apr 15, 2009)

Thanks Trout for doing the work and Golddigger for the gifs.

I can't see much of a difference in brightness myself. The colour is certainly nicer.

I guess the real test will be in a long range shot (150m or more). If ones lets us see further then that's a clear win. I'm also happy with seeing the same distance but seeing it better.

Sometimes I find holding two flashlights up doesn't let me see any further, but what I can see I see much clearer.


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## emu26 (Jun 23, 2008)

Thanks to all that have contributed to this so far. I've been fairly quiet commenting on the pics because like Troutie, I have initially been dubious as to whether or not there was any real change in light intensity, certainly an improvement, to these old eyes at least, in colour, but I didn't think there was much difference in brightness.

Having seen the gives in the garden I do think there is an increase in brightness and certainly a reduction in the spill. The other thing to remember is that warmer hues tend to be not as bright so for us to be perceiving an increase in intensity with a warmer hue, I would suggest that you certainly have increased the usable light coming out the front of the aspheric, and at the end of the day, that's what we all want to see.

Thanks again guys, nice work.


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## BrianMc (Jan 5, 2010)

Great thread. :thumbsup:

Santa is bringing parts for three new lights (tailight and classic road headlight, and a new helmet array and a refurbish of another). Ahorton lenses on the way, too. Picked up some aluminum countersunk washers in two sizes looking for an el-cheapo DIY reflector for the lathe-less. I won't cry much if I drop them either at $.17 and $.20 apiece. A wee bit of polish, a spacer to keep them from shorting the pads and set the height and I have an experiment. 

BrianMc

PS This cost me a pair of Spider Eyes from Troutiie. The price we pay to salve our curiosity!


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## brad72 (Jun 12, 2009)

So I have been playing with recycler collars that I made this morning and trying different radius's and styles, the longest one in the picture is a cylinder with a reflector around the aperture to send light back down into the led die.

One thing I am noticing is that the recyclers seem to make seem to make the phosphor more yellow. It is really hard to pick up with a camera but by eye you can see the projected light has a stronger yellow to it. It does also seem a little brighter but again without propper equipment a little hard to say.


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## ahorton (Apr 15, 2009)

Nice work. 

I think what the phosphor is doing is giving you a bit more red which makes the overall effect a little more of a yellow shade of 'white'.


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## ahorton (Apr 15, 2009)

Any updates from our experimentalists?


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## troutie-mtb (Sep 20, 2007)

ahorton said:


> Any updates from our experimentalists?


not yet I am still waiting for the milling cutter to arive :madman:


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## troutie-mtb (Sep 20, 2007)

OK got the cutter and had another go


















Definitely something going on here


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## ahorton (Apr 15, 2009)

There's definitely a hotter spot on that one. It seems to have lost something at the corners but I don't mind that really.


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## Toaster79 (Apr 5, 2010)

Troutie, do you use 10mm ball nose end mill, or is it something special?


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## troutie-mtb (Sep 20, 2007)

Toaster79 said:


> Troutie, do you use 10mm ball nose end mill, or is it something special?


no its a 5 mm ball nosed mill that has produced the best effect so far

Ash. mail me your address and i will send you some collars to experiment with.


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## Toaster79 (Apr 5, 2010)

So the collar should look something like this?


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## ahorton (Apr 15, 2009)

Email sent!


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## rschultz101 (Oct 5, 2009)

remove the dome,
is a little drastic for my taste.
but taking a razor blade, and cutting the dome in half, 
would think, be very good and enough.
since the die is flat, that should do.
the correct solution, probably be a negative acromat lens,
almost as small as the LED. usually too expensive.
let me know how it goes


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