# How to make a CREE Throw



## NewBie (Nov 5, 2006)

Figured it would be good to show what can be done with a CREE and an aspherical lens, and the throw possibilites.

Please ignore the stop sign, it is blasting the light back. The house is beige, so it doesn't light up very well though (maybe I should pay them to paint it white?):


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## highorder (Nov 5, 2006)

how did you do that??? show us the light!


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## NewBie (Nov 5, 2006)

I held the CREE XR-E in my hand with the aspherical lens.

Another shot:


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## TENMMIKE (Nov 5, 2006)

very impressive


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## highorder (Nov 5, 2006)

wow, I didnt realize the size of the lens. what do the neighbors think?


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## Lit Up (Nov 5, 2006)

NewBie said:


> Figured it would be good to show what can be done with a CREE and an aspherical lens, and the throw possibilites.
> 
> Please ignore the stop sign, it is blasting the light back. The house is beige, so it doesn't light up very well though (maybe I should pay them to paint it white?):



actually the house is what I was noticing. The beam really opens more (say compared to a MagLED) and looks to even illuminate the grass well enough to see it in this pic.

5mm lights still have a purpose as a low-level, but Luxeons to me now are nothing more than a stepping stone to ^that, and if somebody doesn't get these in mass production soon, I'm gonna freak. 

It doesn't even look like it's affected by all the ambient streetlight.


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## NewBie (Nov 5, 2006)

Lit Up said:


> actually the house is what I was noticing. The beam really opens more (say compared to a MagLED) and looks to even illuminate the grass well enough to see it in this pic.
> 
> 5mm lights still have a purpose as a low-level, but Luxeons to me now are nothing more than a stepping stone to ^that, and if somebody doesn't get these in mass production soon, I'm gonna freak.
> 
> It doesn't even look like it's affected by all the ambient streetlight.





You wouldn't even see a 4D LED Maglite in this photo, it would be all washed out by the ambient light.

I just checked, and the MagLED 4D opens up way more than this, and I do not notice it even casting light on the house.

FYI, there are two streetlights down at that end of the block, so the area has plenty of light already.


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## RCatR (Nov 5, 2006)

I'm working on a similiar optic setup, let's hope I can duplicate your results :-D


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## NewBie (Nov 5, 2006)

FYI, the focal length of this 2.5585" lens looks to be 1.4" or so.


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## Lit Up (Nov 5, 2006)

NewBie said:


> > You wouldn't even see a 4D LED Maglite in this photo, it would be all washed out by the ambient light.
> 
> 
> 
> ...


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## Loomy (Nov 5, 2006)

Hey newbie it seems like you posted the wrong image, you accidentally posted a picture of a laser instead of a flashlight


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## glockboy (Nov 5, 2006)

Got any picture of your light?


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## yellow (Nov 5, 2006)

would be interrested in a picture of lens and Led

the 2nd pic, the one highliting the blue (?) pickup, seems like a bit focused.
Have You tried these snap on beam widening things?


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## Long John (Nov 5, 2006)

Hello NewBie

Great work:twothumbs It looks very promising. I would be also interested, to see a picture of the lens and the "business end" of the light source.

Do you use a LE for the Cree? How large is the lens, does the: "2.5585" means the diameter in inches?

Thank you very much, also for sharing this fantastic impressions.

Best regards

____
Tom


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## Gnufsh (Nov 5, 2006)

Awesome! Where can I find a lens like that?


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## matrixshaman (Nov 5, 2006)

Another thread Newbie put up recently shows his lens in one of the pics. It looks big and heavy but what the heck. I'd build a light with one just to have that laser like throw beam.


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## NewBie (Nov 5, 2006)




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## Macaw (Nov 5, 2006)

WOW! Now that's a chunk of glass! Nice clean square wave too...


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## 4sevens (Nov 5, 2006)

you neighbors MUST love you!


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## NewBie (Nov 5, 2006)

Okay, thats an old picture from 2004, so I guess we deserve a more recent one:


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## daveman (Nov 5, 2006)

How resistant is this lense against scratches and shattering?


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## NewBie (Nov 5, 2006)

I would not consider pounding nails with it, or using it to mark a sidewalk.


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## 3E8 (Nov 5, 2006)

Loomy said:


> Hey newbie it seems like you posted the wrong image, you accidentally posted a picture of a laser instead of a flashlight



Haha, what a light. This excitement reminds me of when Core 2 Duo before it was released earlier this year. Making grown men giddy like little kids on Halloween.


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## stoven (Nov 5, 2006)

Where can you buy a lens like that and how much do they cost?


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## matrixshaman (Nov 5, 2006)

As a side note as to what aspherical lenses can do I just tried a little test. Using a Longbow Micra (1 watt Lux I believe - greenish and probably underdriven) I took a glass paperweight resembling the aspherical lens above. It's probably 3" or a little more in diameter on the bottom. It also has etching on the bottom middle as an advertisement for some business. I pulled the bezel off the Micra leaving just the bare LED sitting back in the barrel of the light about 1/2 inch. I held the paperweight in front of it and stepped out back tonight and was able to make some noticeable light on a house about 1000' to maybe 1200' feet away. At around 300 feet there is a fairly bright little square of light coming out of this setup. This is not meant to take anything away from the Cree or tests Newbie is showing. I just wanted to test to see how much light focusing power such a glass dome has on an LED. It's quite dramatic.


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## chesterqw (Nov 5, 2006)

the cree will be better as it's light emitting pattern shows a flood of around 70 degree.

the luxeon however, emits light at around 180 degree.

so most or all of the light is 'squeeze" into the lens for the cree but for the luxeon, light is escaping off from the side.


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## NewBie (Nov 6, 2006)

Went for a drive on the edge of town, and did a few beamshots...
























About 200ft from the side of a large department store:


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## stoven (Nov 6, 2006)

Your latest shot shows the square pattern of the LED dye. Does it look really bad when shining on a surface a few feet away?


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## LMI (Nov 6, 2006)

This is my first post here, and let me thank you for all your great posts, Newbie. I really appreciate your technical bent, too.

I have a question about your aspheric lens, and aspheric lenses in general. They obviously can create a wicked spot beam, but can get an even flood out of them, as well? My rudimentary understanding of optics would say "yes", but you've got the goods.

Sorry if this is a tired question, but inquiring minds and all that...

-Damon


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## x2x3x2 (Nov 6, 2006)

chesterqw said:


> the cree will be better as it's light emitting pattern shows a flood of around 70 degree.
> 
> the luxeon however, emits light at around 180 degree.
> 
> so most or all of the light is 'squeeze" into the lens for the cree but for the luxeon, light is escaping off from the side.



with reflectors and optics it doesnt make any difference does it? i mean these emitters werent mean to be used bare anyway..


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## NewBie (Nov 6, 2006)

LMI, Welcome Aboard!!!

Great first question.

Yes, you can misfocus them to get an even flood, with color fringe on very edge.












The same setup, defocused further:


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## IsaacHayes (Nov 6, 2006)

lol, I was thinking "Stop sign? where? All I see is a bright hotspot!!!" Then I realized that was the stop sign. hahaha. I was about to fall over!!! 2.5 football fields! that's some distance!

Jar: is it the same lens from 2004? (I remember that one as 2"). Thanks for mentioning the focal length!

I bet that suspicious characters lit up by this beam would defiantly think the cops were after them, I mean it's like a helicopter spotlight almost! Defiantly looks like an alien beam from the sky!!!

I think I'm going to build a light with an optic like this even if it doesn't look like a flashlight. I just have to have a laser like beam for spotting things even further than my mag mod. I really wish I had a lathe or could afford someone to build a head/body for it, but likely it will be on a CPU heatsink and a lantern setup all free air/exposed guts. May not be as easy or durable, but might look cooler! Yes it's been decided. I'm going to do it! (power probably by 3AA NiMH).

x2x3x2: yes it does make a difference. These leds can be used bare or with optics (cree makes/offers optics for them). The cree seems more suited for optics with it's narrow beam than for reflectors which need a wide beam to hit the reflector walls. It would make sense that the cree firing most of it's light forward would be ideal to go directly into an optic.


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## NewBie (Nov 6, 2006)

Yes, it is in fact the same exact lens as the one I showed back in 2004. It was kicking around the house gathering dust.


The exposure is much longer on these older photos, but maybe your remember them:


The first one was around February 10th, 2004:







Or this one, more recent from 19 February 2005?


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## IsaacHayes (Nov 6, 2006)

oh yeah, I got the thread bookmarked.  I will be ordering that lens soon (right now!) so others back off as I want one!!!


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## NewBie (Nov 6, 2006)

Could you please send me the link?


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## IsaacHayes (Nov 6, 2006)

Sure! (just please don't post it until I have ordered! hehe) PM incoming.
EDIT: your PM inbox is full. I'll try emailing you.
EDIT: you have email disabled! Clear your inbox!! 
EDIT: PM sent!!!!!!!!! Ordering lens now!!


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## NewBie (Nov 6, 2006)

Ah, thanks, I was wondering why folks stopped PMing me...


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## PEU (Nov 6, 2006)

Are these aspherical lens like the ones used for map reading or they are edmunds optics quality?

I mean its a $10 or a $200 lens?


Pablo


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## AlexGT (Nov 6, 2006)

I am waiting for Edmunds to have back in stock the 27mm aspherical lens to try it with a CREE led, so far the latest mail is for 12/26/06 to be back in stock. Anyone have another supplier with quality optical lenses? Isaakhayes can you send me the link since you have already ordered one? Thanks!

AlexGT


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## AardvarkSagus (Nov 6, 2006)

I also am very interested in where I might find lenses like this. I am looking for something in the 50mm range. Edmund Optics has a 50mm aspherical but the curve isn't nearly as radical as this. Are there any other types around?


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## NewBie (Nov 6, 2006)

These lenses are high quality, not the map ones, but not sure how high quality they are. They do have AR coating on top and bottom surfaces.

www.bgmicro.com
LEN1029 is the one I've been using for the past few years.
1.99 ea

Diameter 2.5585", height ~1.092" focal length roughly ~1 1/4"


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## NewBie (Nov 6, 2006)

.


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## NewBie (Nov 6, 2006)

oops


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## stoven (Nov 6, 2006)

Thanks for the link. Just bought one!


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## KDOG3 (Nov 6, 2006)

LOL. Just sitting here shaking my head. Thats' just plain insane.....


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## IsaacHayes (Nov 6, 2006)

AlexGT: Yeah the BGmicro len1029.


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## Mike Painter (Nov 6, 2006)

NewBie said:


> Okay, thats an old picture from 2004, so I guess we deserve a more recent one:



If that were a properly designed fresnel it would do at least as well, be about as thick as the frosted area shown at the base of the lens, and fit in your flashlight.


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## stoven (Nov 6, 2006)

Newbie,

You wouldn't happen to have any lux readings?


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## IsaacHayes (Nov 6, 2006)

LOL, BGmicro is now SOLD OUT of the lenses. That was fast guys!!! LOL. I got my order in early last night before the info was posted so I should get mine. I ordered 2 BTW!! :naughty:

Mike: point the way to a cheap source of them and I'll follow! It'd be awesome to fit one in place of the mag lens or something LOL

stoven: IIRC 37k lux, allthough the luxeon3 ones were around 32k lux. But this cree seems to be way more than 5k more lux. Perhaps the difference really shows up at distance :shrug:

I will be mounting my lens on the end of a project box, which will house AA nimh power pack, and have a handle with a switch. The Cree will be mounted on a pentium heatsink behind the lens. It will look like some HID lights look like sorta as far as form factor. It will also allow me to test different reflectors and circuits since the led will be mounted on a good heatsink for testing bare. My first test bench setup, and it will be a portable spot light as well!


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## stoven (Nov 6, 2006)

37k? That's pretty high! Is that at 1 meter? What is the spot diameter size (or square?) at 1 meter?


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## Gnufsh (Nov 7, 2006)

I guess I was too slow on the gun. Anyone know of another source?


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## Mike Painter (Nov 7, 2006)

> Mike: point the way to a cheap source of them and I'll follow! It'd be awesome to fit one in place of the mag lens or something LOL



This Tekna light is the only one I've found that uses such a lens. They are hard to find in small sizes with shorter focal lengths.
They were originally used in lighthouses to send a kerosine lantern light (hardly a point source) 20 miles or more.
 shows a rather poor drawing, near the bottom of the page that explains the "translation" from aspheric to Fresnel.
 This pdf does a more complete job.


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## NewBie (Nov 7, 2006)

Lantern lens...






larger photo:
http://www.molalla.net/~leeper/lens2.jpg


BTW, you can stand inside of it.


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## kumar762 (Nov 7, 2006)

last night I picked up a magnifying glass and held in front of my kroma.I got similar results and it did just what these lenses did,but I think I'll still order one 

I also tried this experiment with an incan . . .:thumbsdow nothing good.I'll try and get beamshots tonight if anyones interested?


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## FirstDsent (Nov 7, 2006)

NewBie said:


> Lantern lens...
> 
> 
> 
> ...


Beamshots! Where are your beamshots? can you mod a Fenix with it? The Fenix is my benchmark for all portable lighting -LOL!


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## Mike Painter (Nov 7, 2006)

NewBie said:


> Lantern lens...
> 
> 
> 
> ...



Exactly. That's about 6 feet tall and focused a 6 or 8 inch flame to throw 20 miles.
So a 3 inch lens could focus a much brighter .25 inch light to throw a fair distance.


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## alfaman2 (Nov 7, 2006)

hi all
seems to me
The lens look like those used in fiber optics lighting.


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## IsaacHayes (Nov 8, 2006)

I got my 2.5" Lenses in the mail today!!! :naughty:

Newbie: If I leave it in the aluminum housing, will that make it loose any throw/output since the backside hole is smaller than the lens?


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## RonM (Nov 8, 2006)

Don't hold the beam on the buildings for too long, you may set them on fire! LOL


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## Handlobraesing (Nov 8, 2006)

To make it work right, does it have to be so precise that the diameter is precise to 1/10,000" ?


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## NewBie (Nov 9, 2006)

Handlobraesing said:


> To make it work right, does it have to be so precise that the diameter is precise to 1/10,000" ?




I guess every question that isn't asked is a isn't a dumb question.

No, it has nothing doing with it working or not.


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## NightHiker (Nov 9, 2006)

Newbie: What would the results be like with a smaller diameter lens of the same design? Say, something that would fit inside a mag or smaller.


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## NewBie (Nov 9, 2006)

There are many variables, so it is hard to say. There are quite a few asphericals, and variations on the aspherical lens itself. There is also various focal lengths, which will in the end, gather more or less light from what comes out of the XR-E package. As the focal length increases, less of the light from the LED will hit the lens, and thus less of the light will be directed to the spot (the throw part of the beam).


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## IsaacHayes (Nov 9, 2006)

Jar, what about my question above? Thanks.


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## NewBie (Nov 10, 2006)

Well, one would figure it would make a slight difference, try it is all I can say.


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## Christexan (Nov 10, 2006)

The lens diameter and focal length affect the output as follows (in tandem with each other)...
picture a cone of light from your source, to the lens... only light that falls within that direct cone is going to be optimally output. The larger your diameter, the larger area of the output source will be captured (the wide end of the cone is as large as the base surface area of the lens), at a given focal length.
The closer your source is to the lens (focal point), the more light is likely to be within that cone. This is why LED optics, and reflectors, put the light source WITHIN the unit, so that all light is "captured" by the unit.
For practicality with a generic lens, you'd want to figure out what portion of light you want captured, and base focal length and diameter on that figure. 
Using a Cree XR-E, you get "50% brightness" at an angle of 35-degrees off-axis/70-degree wide cone. Lots of trig, calculus, testing, and algorithms involved to get how much light that actually is compared to what is emitted total (batwing versus lambertian patterns for instance would have a huge difference in total lumens emitted within and outdside that 50% brightness (candela)number, for instance). Anyhow... skipping all that...
If you wanted to catch a 70-degree cone of light from a Cree, then you'd need a lens whose focal length and diameter match that cone. I'm not going to do the math, but the specific numbers are irrelevant, using "pretend" numbers, a 3" diameter lens at 1" focal length could grab the exact same light and pattern as a 6" diameter at 4" focal length, just as a made-up example (it could be a mile away focal length as long as the diameter is sufficient to cover that 70-degree cone, it'll be the same ouitput (minus atmospheric gas/dust/temperature gradient losses of course)... the same principal as telescopes, the farther something is, the smaller area of exposure we have to it's source emissions, and so the larger the lens/mirror needed to capture as much as we can of the light we do receive. 
So you can't look at specific numbers without other parameters (using same type/shape lens);
At a given diameter and focal length, a lens can grab x amount of light at focus. To capture more source light, increase base diameter at same focal length and shape, or find a shape with a reduced focal length at the same diameter (or both) to increase the angular area of the cone that falls onto the base of the lens.

IsaacHayes - regarding the frame, yes, it will affect the light output, to the degree that the percentage of light falling in that area won't make it to the lens... but if you already are catching 80% of the light, including most of the main emitter beam pattern, and the aluminum edge is only blocking 1% of the total output, it won't be noticeable. 
The Cree's pattern drops pretty fast outside of the 70-degree FWHM figure (typical lambertian pattern, so if you are say 50-degrees off-axis (or at the 100-degree "ring" of the output), chances are that the area blocked will only be a tiny fraction of the light output anyhow. (Find the focal length of the lens, do some quick calculations to find the angles from the emitter center axis, to the edge of the lens (or a protractor for a quick and easy check), and if the angle from the center to the frame is anything significantly larger than say 40+ degrees, there isn't much light left to collimate there.


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## metalhed (Nov 10, 2006)

Christexan -- Excellent explanation...as far as I understood it of course. 

Now I hope this isn't a question that shouldn't be asked. 

But are the aspherical lenses similar in design (and effect) to the lenses used in the River Rock 2AA and 2C LED flashlights? And, to follow up, could one of these lights be modded with a Cree to take advantage of the lenses?


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## IsaacHayes (Nov 10, 2006)

Yes good info! I think I will test it by first getting them close, then look at the light hitting the housing. If it's not that bright then, I won't worry about it. If it is, then I'll mod the holder.


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## LEDite (Nov 11, 2006)

I have played with the same lens that Newbie was using. It's from a DLP projector.

I have also used a couple of smaller plano-convex lenses on the Cree XR & XR-E leds.

The ability to form a square spot is amazing. You can see the exact image of the die of the LED when viewed up close.

The smaller lenses work very well in flashlights.

One is approx. 29 mm in diameter with a focal length of about 1". It fits in my Golston 7W light.

The other is approx. 25 mm in diameter with a focal length of about 1/2". I use this smaller one on a CREE XR UV lithium rechargable light I produce, the CREE is mounted on a copper plate about 3/8" inside the case:







I do have about 35 of the 29 mm lenses if anybody is interested.

Larry Cobb


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## Gadget_Guru (Nov 13, 2006)

Here is a good deal on a 50mm diameter aspherical lens that may fit right in place of the original lens of a C/D Mag-Lite. The focal length is 30mm.

Here is another one from the same vendor, with a slightly longer focal length.

I just ordered a few of the first one, so we'll see how well they work...


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## IsaacHayes (Nov 13, 2006)

Cool, keep us posted!


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## NewBie (Nov 13, 2006)

Well, we had a windstorm blow thru, which knocked out the power out. So, dodging flying garbage cans and such, I managed to go out and snap a few shots, later on, one of the neighbors came out and was asking about my cool "white laser"...

Anyhow, I have no camera setting information, getting buffeted about, I snapped a few off and went back inside. 






Over exposed:





Under exposed:


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## IsaacHayes (Nov 14, 2006)

Hahah I love it! White laser!! I remember when your connection was lost and said, there goes Jar!


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## NewBie (Nov 14, 2006)

IsaacHayes said:


> Hahah I love it! White laser!! I remember when your connection was lost and said, there goes Jar!



That is exactly when our power went dead, at least they managed to get it up by supper time today.


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## LowTEC (Nov 14, 2006)

NewBie said:


> Well, we had a windstorm blow thru, which knocked out the power out. So, dodging flying garbage cans and such, I managed to go out and snap a few shots, later on, one of the neighbors came out and was asking about my cool "white laser"...
> 
> Anyhow, I have no camera setting information, getting buffeted about, I snapped a few off and went back inside.
> 
> ...



I think these shots deserve a sticky :lolsign:


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## NewBie (Nov 14, 2006)

I'm glad you enjoyed them!

You will note the "test range" is the same one as in some of the earlier photos.


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## DM51 (Nov 14, 2006)

Now you'll have to rename this thread "White Laser". 
Are you going to build some more of these for sale?


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## Twellmann (Nov 14, 2006)

Would It at all be possible to use more than one point source with an aspherical lens?

Something like this http://groups.msn.com/_Secure/0RwCHG9cVJRif4*Epj6yr2LLOKde46z1oz9u1QU4EHf2U7rumkKL6JZ8d8BbKDMiYIxA7!cNZ!kXTly9P9LAKkjQs3GiPxV13FowxFh*7RM4/CreeXre3.jpg?dc=4675597790701127996


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## LowTEC (Nov 14, 2006)

Twellmann said:


> Something like this http://groups.msn.com/_Secure/0RwCHG9cVJRif4*Epj6yr2LLOKde46z1oz9u1QU4EHf2U7rumkKL6JZ8d8BbKDMiYIxA7!cNZ!kXTly9P9LAKkjQs3GiPxV13FowxFh*7RM4/CreeXre3.jpg?dc=4675597790701127996



^^It almost seems like you want to burn a house down with 3 of those focused "white lasers"


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## Twellmann (Nov 14, 2006)

:rock: sure why not!!

It was actually also an attempt to utilize the space under the lens, if possible.
I'm afraid though that more than one point source will result in more than one hotspot(obviously?) maybe far out akin to the luxV with four dies.


Seven XR-E's under an aspherical lens would certainly tickle my fancy.......


The fit and machining has to be extremely precise I guess... to make seven HOTspots align at ~200 feet isnt trivial


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## IsaacHayes (Nov 14, 2006)

Twellmann from my experience, it focuses the image of the die only if the led is right in the center. It doesn't really collect light that is shined into it per say, but focuses what it sees at a certain distance. You can't really just fire light into it and it automatically focuses it into a beam. Think of it as a magnifier, and you can only get it in focus by centering what you are looking at at the right distance... If you had 2 more leds side by side the main one, it might be close enough to be in the center of the focusing range, but it may just give some spill light or corona to the main beam... That might be work checking into. I can see how much play side to side/up down it has and see if that is enough room to put another led next to the main one...


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## Twellmann (Nov 15, 2006)

IsaacHayes said:


> Twellmann from my experience, it focuses the image of the die only if the led is right in the center. It doesn't really collect light that is shined into it per say, but focuses what it sees at a certain distance. You can't really just fire light into it and it automatically focuses it into a beam. Think of it as a magnifier, and you can only get it in focus by centering what you are looking at at the right distance... If you had 2 more leds side by side the main one, it might be close enough to be in the center of the focusing range, but it may just give some spill light or corona to the main beam... That might be work checking into. I can see how much play side to side/up down it has and see if that is enough room to put another led next to the main one...



thanks... well that was pretty much what I thought too..

Then it could just be for flood, or something, depending on HOW it exits the aspherical lens ???


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## AilSnail (Nov 22, 2006)

Christexan, check your numbers again? For a given cone angle, diameter is proportional to focal length..

Also, a large lens would be brighter than a small one, if the fl is proportional. This is because the emitter is further away and thus appears like a smaller point, and the emitting area deviates relatively less from the actual focal point. same as reflectors.

Newbie, whoah those last 3 pics are fine! Do you have them hirez?

You would have to have some more lenses or mirrors to make all the three leds appear to be at the focal point. Probably could be done with three smaller magnifying lenses?

Pull a line from fp to a point on the back surface of asph, half radius from center. Place an led along this line, in a plane perp. to the line. Put a lens centered on the line, same plane as led. do it three times. You would get a shorter lamp also, even the asph. fl is the same.


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## Raybo (Nov 24, 2006)

Gadget_Guru said:


> Here is a good deal on a 50mm diameter aspherical lens that may fit right in place of the original lens of a C/D Mag-Lite. The focal length is 30mm.
> 
> Here is another one from the same vendor, with a slightly longer focal length.
> 
> I just ordered a few of the first one, so we'll see how well they work...



Thanks for the info Guru, I picked up one of each lens.

Anyone else going to try it out?

Ray


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## tspoon (Dec 5, 2006)

Gadget_Guru said:


> Here is a good deal on a 50mm diameter aspherical lens that may fit right in place of the original lens of a C/D Mag-Lite. The focal length is 30mm.



I have just completed testing my new bike lights featuring this lens, and can confirm they work well. Thanks for the link. (although it should be noted that the ones I recieved were 48mm O.D and 43mm not counting the 'flange')

I'll include a pair of shots of the completed (essentially) lights on the bike. I used 4 Cree XR-E's. The dark part holding the lens is a 40mm waste pipe rubberseal-joiner, and the rear is an aluminium cap/heatsink I machined up at work. They have the same I.D and I used a 40-32mm waste pipe reducer inside to join the base and lens holder. They are held together with 2 pot glue. The lens is sealed against the weather with an o-ring, and has another behind. It probably won't be totally weather proof as the pipe fitting is not strong plastic as such.

All four lights are then attached to a length of angled aluminium extrusion such as would be used in an aluminium window frame, which itsel is held to the handlebars by two clamps nicked from commercially available blinky bike lights.

The power comes from a hub generator, normally specced to run at 6v3w, but will at a guess be supplying around about 13.2v, at roughly 350-400mA. This keeps the lights from becoming too warm, as they are star mounted, and as elsewhere noted, a less than satisfactory implementation. This could be important, as my ride to work is generally about 70 minutes in length.

I can't supply any beam shots as set up, as the bike only supplies current when moving, making photography difficult. However, once I had the beam pointed where I wanted it, this proved to be easily the best setup I've ever had. It should be noted that there wasn't nearly enough illumination on the road immediately before the bike, as the aspheric lenses concentrate (nearly) all the light in one spot, and its better (imo) to have that spot somewhat further from the bike. But Oh what a Spot. Bright White - you can almost see the tar melting.

P.S others have commented on the way that the beam projected is square, an exact image of the die itself. While setting up the focal length of these fittings I found I could see the fine lines in the die reflected in the projected beam, from 5+ metres away., when set up 'just so'.












Cheers Newbie and others. Until I saw your recent posts I had never heard of an aspheric lens. Now I've got the bike light system I've been scheming after for yonks...


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## Light-Eater (Dec 5, 2006)

Wow, nice, can we have some close up shots of the construction please, tspoon?


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## Long John (Dec 5, 2006)

:goodjob: tspoon, great work 

Please show us beamshots :rock:


Best regards

____
Tom


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## chris_m (Dec 5, 2006)

Surely with a 6V 3W dynamo, since this is a current driver the output will be ~500mA, at whatever voltage is required for that (given sufficient speed)? In fact I'd suggest the combination of such a dynamo and LEDs is superb in this application as at lower speeds the LEDs will get dimmer with less current draw, but due to increasing efficiency not so much that it's an issue given the slower speeds.


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## tspoon (Dec 5, 2006)

In theory the current will drop off slightly as the voltage increases, which is the reason I'd expect slightly less. Possibly at higher speeds (30kph+) it will be very close to 500ma. I might try to strap my DMM to the front carrier tonight to check this out.
I will try to also get somehow some meaningful beam shots, although I'm not even sure my lower midrange camera is capable of much here. It's morning here right now and I have a very full schedule. In the meantime heres several more shot of a unit with the front screw on cover off. Its hard to show much more than this of the construction now that its glued up. I specifically painted them a dark colour, hammer finish paint to hide the numerous construction faults


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## Fiat Lux (Dec 6, 2006)

This thread is fascinating. I've been a lurker, but this thread made me have to join. 

God Bless


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## Light-Eater (Dec 6, 2006)

tspoon, I wonder what kind of strange looks you would get riding with these babies on . BEAM SHOTS Please!!


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## TigerhawkT3 (Dec 6, 2006)

Suggestion for beamshots:

Prop up the rear of the bike and work the pedals with your hands. One you've got it spinning good and fast, snap a quick pic.

AWESOME work! :goodjob:


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## IsaacHayes (Dec 6, 2006)

Fiat Lux: Welcome aboard! I'm sure you'll eventually build some mods of your own! 

tspoon: NICE work there!! Have you thought about making one of them a wide beam? If you move the led/lens closer, it will widen out some. You could even have a progression, one really wide, one medium, and 2 spot... Might help some...

Hmm. Maybe I could use pipes for the housing of my big ol optic too.... hmm.


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## tspoon (Dec 6, 2006)

I tried for some beam shots tonight - no go unfortunately. The camera (and more likely my photography skills) was not up to the job. I managed to measure the current - about 300ma at 20kmh, rising to 400 at 30kmh. This in itself caused problems as the dynamo has 'smarts' inside which (gradually) turn the dynamo off if not drawing around 500mA, and this is what happened during tests. Its supposed to prevent burning out the rear light on a 2 light system if the front light is blown. I'm not 100% sure if its high voltage, or low current based, but I had to cut back to 2 Lights going for tomorrow mornings commute. With 2 the current will be around 500mA.

TigerhawkT3 - unfortunately on my bike the dynamo is in the front hub, so you pretty much need to be moving to have light.

Sorry all for no beam shots. Suffice it to say that with 2 going they're still the best light setup I've yet had, and for the short period I had 4 I couldn't get the stupid grin off my face... When pointed in a high beam fashion they were approaching the throw of a cars high beam (maybe not the modern ones) although not as wide. Of course for cycling you don't need to see quite that far so you angle them down to avoid annoying oncoming traffic.

I'm off to bed.. - cheers

edit : Last word - got all 4 going after a lot of shagging around - turned out to be a real wierd problem with the bridge rectifier. Only found that out after completely stripping down the hub generator, to the point of rewinding it. I may end up pointing one light lower to cover the area close to the bike. Maybe, as suggested, experiment with defocussing it too.


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## NewBie (Dec 10, 2006)

tspoon said:


> However, once I had the beam pointed where I wanted it, this proved to be easily the best setup I've ever had. It should be noted that there wasn't nearly enough illumination on the road immediately before the bike, as the aspheric lenses concentrate (nearly) all the light in one spot, and its better (imo) to have that spot somewhat further from the bike. But Oh what a Spot. Bright White - you can almost see the tar melting.
> 
> 
> 
> ...




Wow, thats just awesome! Anyone call your bike a Beamer yet? You might try defocusing one of them if you want close up light on the ground, or putting a diffuser over one of the LEDs.

*Very Nice!*


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## tspoon (Dec 10, 2006)

Last night I pointed the centre two down in relation to the outside two and 'defocussed' them slightly. This is an improvement. I then pointed the entire array down ever so slightly also, bringing more improvement. I'm now on my 4 days off (shift worker) and plan to move two of them to just below the front carrier. By being closer to the road I can 'spread' the spot closer in to the bike.

The change caused by defocussing the lens was unexpected. I moved it about a millimeter closer. When pointing the array at a wall about a metre away and spinning the wheel the defocussed fittings are noticeably less focussed than the two 'high beam' fittings. however by the time they hit the ground about 15 feet away I can see the lines on the LED die again and the two 'high beam' LEDs are less well defined than the centre two. Wierd...


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## garageguy (Dec 13, 2006)

What about a Cree in the River Rock 2C. The lens should work well. Has anyone tried this yet.


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## AndyTiedye (Dec 13, 2006)

No need to aim all 4 at the same spot, is there?

How much does the system weigh?


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## tspoon (Dec 15, 2006)

The heaviest part of each fitting is the lens. The whole thing at a guess may weigh 500 grams, which is a little much for a cycle light. I've since put them on individual mountings, and am working towards a good beam pattern for road cycling i.e. taller and narrower, rather than wider and shorter. A little closer to the bike too.


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## KDOG3 (Dec 18, 2006)

Thats just crazy. The beam looks like its really blue though. If we could just get a warmer tint...


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## NewBie (Dec 18, 2006)

You can.


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## 65535 (Dec 19, 2006)

NewBie how can I get this lens? I need one.


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## LightForce (Jan 4, 2007)

Maybe lens from car headlight projector? Won't it be good?


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## hizzo3 (Jan 4, 2007)

you can make 2 hi's and 2 lows and then have a 3 way switch, high low and both. try the lenses in plastic, that would be lighter, assuming that they are glass now. 

i know that auto projectors use a cut off, dunno how that would reflect back into the refelctor though....may be good or bad


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## NewBie (Jan 6, 2007)

65535 said:


> NewBie how can I get this lens? I need one.



I'd go poking around the various optical surplus places, searching for aspheric, aspherics, and aspherical. IMHO, I'd really want to pick out parts with as large of a diameter as I can get, with as short of a focal length that I can get, to collect as much light as possible.

Recently Surefire finally adopted apsherics, because SAIF designed the optics for the KROMA. If you ever get a chance, take a close look at the lens profile.


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## HaPPI (Jan 6, 2007)

65535 said:


> NewBie how can I get this lens? I need one.


 
I saw a pair of driving lights in the WalMart auto area for cheap that have lenses. Around $15 if I recall. See if they will fill the bill?

HaPPI


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## SuperNinja (Jan 9, 2007)

All Electronics and Electronic Goldmine have some lenses.

http://www.allelectronics.com/cgi-bin/category/355/Lenses_and_Optics.html

http://www.goldmine-elec-products.com/products.asp?dept=1096


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## martonic (Mar 3, 2007)

Here is an idea for "reasonably effective" collimation of the output of multiple small light sources. This is a seat-of-the pants idea, needs testing etc.

Place multiple leds in a circle centered around a point slightly behind the focal point of a large (say 3 to 4 inch diameter) parabolic (section) reflector. The distance behind the focal point is equal to the radius of the circle. All led's point forwards (parallel to axis of reflector).

Then, use a (fairly thin, flat side inwards) plano-convex lens to correct for the offsets of the sources from the focal point of the reflector. 

Using this method, it seems possible to collimate most of the foward-emitted light within a few degrees. The reflector does much of the work, and the lens tightens it up.

Any thoughts on this idea?


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## ktronik (Mar 3, 2007)

great looking lights!!! :goodjob: 

I have done a lot of work with hub dynamos & LEDs...

I have many different circuits you could hook up to your dyno hub, to give different power cruves, for different types of riding...

one circuit will pump up to 1A in to 3 LEDs (peak @ 30km/hr)...but the main circuit I use, is the one that gives only 80ma variation between 18km/hr-30km/hr (peak around 560ma)... & uses a voltage doubler circuit for extra boost below 10km/hr... if you need any info please email me for a spreadsheet of the stats & pics if the circuits...

keep up the great work

best

Ktronik


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## tspoon (Mar 4, 2007)

I've seen various designs around the web, but probably don't really need to worry about low speeds, as my commute is relatively flat and the lowest speeds encountered would be 13-15 kmh on a particularly windy day. For now I just use a schottky bridge rectifier with 2 mfd of smoothing/reservior caps for lowish speeds. I coupled that with a 1/2 farad supercap standlight circuit which gives about 90 seconds running front light(s) and rear (front fairly dimly). In the same box is a dual 555 flasher circuit for the rear which alternates two flashers in a fairly simple setup. It all fits in a pretty small project box mounted under the handlebar stem, from where I can turn all lighting on/off with one switch - very handy.

I'm intrigued about the 1a at 30kmh - does that use series capacitance to balance out the dynamo inductance perhaps?
My current setup is now only 2 aspheric beams with an Inoled fitting from which I stripped out the electronics and wired the Luxeon LED in series with the other 2 Cree's. This provides a lot more close in spill, leading to a better all round light setup. I've just ordered an SSC P4 to see how much more light can be had from the Inoled fitting. I've also gone and purchased some 30mm aspheric lenses from the same supplier to see if I can get the same results in a smaller fitting. I decided to make the whole fitting on the lathe, but it's a little beyond my skill level, however I'll keep trying different ideas.


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## ktronik (Mar 4, 2007)

tspoon said:


> I've seen various designs around the web, but probably don't really need to worry about low speeds, as my commute is relatively flat and the lowest speeds encountered would be 13-15 kmh on a particularly windy day. For now I just use a schottky bridge rectifier with 2 mfd of smoothing/reservior caps for lowish speeds. I coupled that with a 1/2 farad supercap standlight circuit which gives about 90 seconds running front light(s) and rear (front fairly dimly). In the same box is a dual 555 flasher circuit for the rear which alternates two flashers in a fairly simple setup. It all fits in a pretty small project box mounted under the handlebar stem, from where I can turn all lighting on/off with one switch - very handy.
> 
> I'm intrigued about the 1a at 30kmh - does that use series capacitance to balance out the dynamo inductance perhaps?
> My current setup is now only 2 aspheric beams with an Inoled fitting from which I stripped out the electronics and wired the Luxeon LED in series with the other 2 Cree's. This provides a lot more close in spill, leading to a better all round light setup. I've just ordered an SSC P4 to see how much more light can be had from the Inoled fitting. I've also gone and purchased some 30mm aspheric lenses from the same supplier to see if I can get the same results in a smaller fitting. I decided to make the whole fitting on the lathe, but it's a little beyond my skill level, however I'll keep trying different ideas.




Don't want to hijack this thread...please email me & I will send you all the test stats...

best

Ktronik


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## pokkuhlag (Mar 27, 2007)

Did anyone buy the smaller aspherical lenses to compare with the 52 mm ones?


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## johnny13oi (Mar 27, 2007)

This has probably been answered but where can I get that lens and for how much .. sorry I looked through a few pages and was too excited and just scrolled to the pictures.


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## PhantomPhoton (Mar 27, 2007)

I think you can get the lens here.


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## joedm (Mar 27, 2007)

I'm interested to see what the lens looks like on Newbie's flashlight? 
C'mon.... give us some pics.. =P


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