Long Throw Head/XR-E...better results...

Ganp

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Carclo,the makers of the 2 degree collimator I am using in my LED Head project (here ) do not have a Cree XR-E compatible version yet and I understand that they are waiting to see if there is enough demand.

So...I tried modifying one of mine to see if I could use the Cree LED with it. I had hoped that it would work OK, but I have achieved no practical improvement over Luxeon LED's with this optic. :mecry: Not surprising really as it is designed for Lux lll's and Lux 5's......but I thought it was worth a try and here is how it turned out.

The collimator needed to be "bored out" at the back to allow the XR-E to sit into the optic more and achieve better focus. This resulted in a large area of the silvered mirroring being removed. :sweat:

IMG_5068copy.jpg

Standard collimator.


IMG_5062copy.jpg

Collimator modified for XR-E.


IMG_5175.jpg

Modified - front view.



Here are the results, with a U bin Lux lll for comparison.(The modification for the Luxeon collimator is much less severe). All at 1 metre.


XRE-Luxlllstdcol.jpg

Focusing with standard collimators.


XRE-Luxlllmodcol.jpg


Focusing with modified collimators.


LuxlllXREmodcol.jpg


Overexposed to show the spill.


LuxlllXREmodcolb.jpg


Underexposed to show center brightness.


The XR-E modified collimator gives much better focus, but the center spot is no brighter than the Luxeon. IMO this is mainly due to the removal of the silvering. I tried placing some non-conductive silver foil around the LED and it did slightly increase the brightness. The spill IS brighter and more concentrated around the central area.

If I had used a heatsink with a pedestal for a Cree emitter, and removed the corners of the LED base, then I could possibly have bored out to a smaller diameter and obtained better results.

So...until I have time to work on this some more I'm sticking to Luxeons with this optic, and they do throw well. But it would be nice if Carclo made a XR-E compatible optic of the same fitting so that the LED Head could take advantage of the Cree's extra lumens.


Colin.

Edit...Now some better results in post 4.
 
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dabiscake

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Re: Long Throw Head/XR-E...I'M NOT CHUFFED!!!

Nice pics, I have one 2deg I was going to try as well when my Crees come in. I guess you've pretty much covered it here. Thanks!
 

Ganp

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Re: Long Throw Head/XR-E...I'M NOT CHUFFED!!!

At last I am getting better results with the XR-E and the 2 degree collimator, although the mods to the optic are quite severe....changing the center pocket that the LED lens sits in, and having to polish it back to a good surface.

I cut as much as I could from around the metal ring of a Cree, and mounted it on a heatsink with a short pedestal. It would be better if even more was removed, but this leaves hardly anything of the solder points. With all this cut away it is possible to recess the LED into the back of the collimator without having to remove so much of the silvering, and it is definitely making more of those extra lumens.

creeonpedestal1.jpg



Here are the beamshots comparing with a U bin Lux lll, and a V bin Lux 5W. This Cree is an early P bin from Cutter. In use the eye adjusts for the hotspot and the spill is not very apparent.


Trio-underexposed.jpg

Underexposed to show the hotspot.


Trio-normal.jpg

Standard exposure.


Trio-overexposed.jpg

Overexposed to show the spill.
 

AilSnail

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Good work! Still looks like the luxiii is brighter? any idea how the carclo compares to a mag C/D reflector? Here is a beamshot of its smaller sibling, a 42mm, lux3 Ux1L, ca 600mA and 3.7v (greenish) vs cree P3 WC in fenix p1, ca 275ma and 3,18v (blueish). I didn't manage the focus you seem to be getting with the 50mm I have either - they seemed pretty comparable to me. Perhaps I need to fiddle a bit more with them. Maybe it has to do with the joker different image location?
315947226_25e0fb3e1e.jpg

310203633_c076b7367d_o.jpg
 
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Ganp

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Lunal_Tic said:
Any chance you've tried the SSC. Isn't it's beam dispersion closer to that of the Luxeon?

-LT

Although the SSC P4 is similar to the Luxlll in beam pattern and physical dimensions, it does not focus well in this collimator.
The beam is very similar to the Cree XR-E, and modifying the collimator may focus it, but does not put the extra lumens into a usefull spot or spill.


Colin.
 

SteveTheReaper

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Dec 8, 2006
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You should try the Edison Opto KLC8. It's die height is much closer to the that of the Luxeon than the SSC P4.
 
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