Narrow beam reflector for 30-40W LED

Hi guys

I just became a member here. Did the misstake and tried CPF first.
Posted in the wrong forum and got Gretas kind greetings……

Im planing to build a 30-40W LED light from scratch, housing and everything.
I have the driver built since before and it is processor controlled so it can be used for anything up to 150W.

My idea is to have a single, tripple och quad led solution with a reflector solution that gives me a spot at about 7-8 degrees.

So far I have been looking a using XM-L2 U2, 3 or 4 of them depending on what reflector I can find.

Can someone here help me find a suitable reflector/reflectors for my build?

I have looked at using this one LED-TECH.DE Online Shop

I have a limit of 58mm diameter to fit the reflectors in. The depth can be changed to what is needed.

Welcome to BLF, Lumpen!

Those are great looking reflectors you linked to but I doubt you will get 7* beam from them with an XM emitter. Those are designed for use with an XR-E emitter which has a far tighter beam to start with. Your better bet might be with 3 or 4 20 mm Carclo 7* TIR optics in conjunction with 3 or 4 dedomed XM-L2 emitters. ;)

Please keep us updated on your project. I for one am very interested to see what you have up your sleeve. :)

Since you are building everything from scratch, maybe you can try aspheric. The beam might be ugly at certain distances, but this will get you an intense hotspot. Remeber to use Noctigons/Sinkpads since you are planning to drive them hard.
I reccomend active cooling since you are doing your own host

I will use watercooling so the heat will not be any problem :wink:

Which one of them do you mean is aspheric likevvii? The link you posed is to several reflectors and none of them has any spec about the beam degree.

JohnnyMac any place I can find those reflectors? I goggled and found the manufacturer but they don’t specify the degree on them. just the diameter.

My goal is to have a light at about 3000Lumens and a really tight beam. Like a laser sword.

laser sword = asperic. All those reflectors are pretty much the same thing (parabolic). You cant really choose what beam you want when using reflectors for LED’s other than using the “orange peel,” bumps on the reflective side to make beam wider. I think the reflectors I showed you are all basically 5-10 degree beam. Aspheric lenses can be from 5 degree to 200 degree depending on how far you put them away from the LED. I own both an asperic and reflector light, Aspheric is much cooler for throw since there is no light spilled out. Try Xpg2 instead of xml2 if you want good throw, and of course…. dedome.

This is greek to me… what is the difference between a asperic reflector and a reflector? I don´t understand?
And what is dedome?

I looked at the xpg2 and they have only half the lumens of the xml2. Why would the less bright one be better?

There is no simple way to explain it to you. You need to know what you need to know or else you end up building garbage. 90% of my lights are from pure scratch and probably 40% of them are somewhat useless because I did not know any better.
If you want throw, you need the brightest surface area. Amount of Lumens compared to your Area. Xpg2 is 1/4 the size but only half the lumens. I don’t know the math but this means more throw. This is a aspheric lens: Lens I suggest you to buy one of these and try it out. If you do decide to try one, buy THIS ONE. I bought over 8 lenses from different people and they do not focus as good as this one. (I am not related to this seller.)

Since you do not know what dedomed means, that means you need a lot of reading on “throw” try searching for some keyterms: throw, pencil beam, deep reflector, throw king, dedome, Wavien Collar.
DrJones’ magical text

Good luck, I suggest you start small.

That made a big difference. In your first post your wrote “reflector” and now you are writing “lens” and the link you posted was to reflectors.
This is why I didn´t get it.
I understand how a lens works, but I had hoped to be able to use a reflector instead.

Lumpen what you are trying to achieve is what many of us here are trying to achieve also. I'll outline the basics for achieving a big thrower:

- You want as high as possible surface brightness per mm2. I'm not too sure about MT-G2, but an XP-G2 has the highest surface brightness per mm2 (or brightness density, I don't know what it's called) and an XM-L2 has the second highest surface brightness from Cree. Not too sure about SST LEDs from Luminus Devices.

- You can increase an LEDs surface brightness by making the apparent die smaller. This is done through de-doming which is the removal of the silicon dome. If done properly will double your throw (in lux, not distance).

- The bigger the reflector, the more focused your beam will be. The perfect ratio of width to length hasn't exactly been worked out yet, but there also isn't much discussion or research going into it. Aim for a reflector as big as possible. A member here, Xandre (from taschenlampenforum) uses 89mm reflectors in his 2million lux thrower.

- Any light from the LED that doesn't hit the reflector will become your 'spill', so try to get as big as a reflector as possible.

- An XM-L2 will have less throw than an XP-G2, but more lumens and therefore a generally brighter spill and wider hot spot.

- Achieving high drive levels is important so minimise resistance in the circuit as much as possible by using larger wires. You won't be breaking any records driving an XP-G2 at 3A.

- XP-G2 can be safely driven up to 5A, XM-L2 can be safely driven up to 6A - probably higher with good thermal management. You are using water cooling so you can probably drive them much higher as you're not relying on conduction and radiation (marginal), but conduction, radiation and convection.

- 4x the lux/candela(cd) = 2x the distance.

Eg. (to 0.25cd):

50k cd = 447m,

100k cd = 632m,

200k cd = 894m

There's probably more but I can't think of much more off the top of my head. Good luck.

Thanks for a great reply!

Just to be clear, Im not after setting any records or even get close to them.
I just want a light that has a good spot and that can shine 20-30m away, not more. But as bright as possible and a little halo is ok!

Im not after distance or records, just a good spot.

Is it possible to use more then one emitter when you are using a lens or is it going to cause problems?

I have build video lights before with a lot of spread, but not a narrow beam like this.

It’s definitely possible to use more than one emitter. You can have separate reflectors or reflectors which overlap each other.

But in any case you’re only looking to shine 20-30m away. This is definitely easy to achieve and doesn’t need watercooling. Modified lights such as the Supbeam K50 & K40, Thrunite TN31 & TN32, Fenix TK61, BTU Shocker (which has three emitters) can throw over a kilometer easily. Now as for how much you’d be able to see, they’d probably be good for about 600-700 meters with the naked eye since there’d be a lot of glare from the beam itself.

For a good spot to shine 20-30m away you should look towards an aspheric light this here:
It will definitely shine 30m, I’m assuming it has around 45kcd which is good for 424m to ANSI standards, and closer to 200m that you’ll actually be able to make things out at.

Im going to have the light in water so the cooling comes anyway.

The one you linked to is nothing I can use, Im making it from scratch so I don´t want to mod a existing light.
Mine is going to have external batterypack and be waterproof.

Watercooling is nice, but a 40W light does not need water cooling at all! A simple fan would do the trick.

Do post pictures when you are building it!!

As I wrote before, it will be in water so I cant change that.

Im still struggling to find a one piece reflector to use with 4 leds that has a narrow beem.