# Cree XP-L, XM-L performance in an XP size package



## bose301s

200 lpw, 1079lm @ 10 watts 85C. Impresses me.

http://www.cree.com/News-and-Events/Cree-News/Press-Releases/2014/May/XPL-intro

http://www.cree.com/LED-Components-and-Modules/Products/XLamp/Discrete-Directional/XLamp-XPL


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## sticktodrum

Oooooh, pretty. Can't wait to see what it turns up in.


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## newbie66

I wonder how's the tint going to be like....


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## mds82

Hot Damn... This looks like the XB-H, but in the standard XP Package. According to Mouser here is the price for these as well 
Part number: 
[h=1]XPLAWT-00-0000-0000V4051[/h]
  1:  $6.10  
  10:  $5.87  
  50:  $5.64  
  100:  $5.40  
  200:  $4.70

 
 500:  $4.46  
  1,000:  $3.09  
  2,000:  $3.01  
  4,000:  $2.93


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## Der Wichtel

Nice, I think it's time to build a new light


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## RetroTechie

Checking the datasheet, I'm reading 150+ lm/W for the cool white, highest output bin. More if you can keep the LED cool. Those are some amazing numbers for a LED this size & at those output levels... oo:

Looking at the spectrum graph, I'd hesitate to use this for general lighting purposes. But for flashlights: PERFECT!

With this as a drop-in for XP-G(2), I'm wondering what Cree comes up with as XM-L(2) drop-in... Looks like this might be the new "gold standard" where XP-G2's were used before.


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## m4a1usr

RetroTechie said:


> Checking the datasheet, I'm reading 150+ lm/W for the cool white, highest output bin. More if you can keep the LED cool. Those are some amazing numbers for a LED this size & at those output levels... oo:
> 
> Looking at the spectrum graph, I'd hesitate to use this for general lighting purposes. But for flashlights: PERFECT!
> 
> With this as a drop-in for XP-G(2), I'm wondering what Cree comes up with as XM-L(2) drop-in... Looks like this might be the new "gold standard" where XP-G2's were used before.



I like your thinking! :twothumbs"


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## Canuke

And the heatsinks get smaller again.

I notice that CRI's only get over 80 in the warm white zone... neutrals top out at Min. 80 and cool whites will just be "standard".


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## ShineOnYouCrazyDiamond

This is a potential game changer for XP based lights. Very similar, but slightly lower Vf curve.

3.0A support - bring on a Vinh modded V10R!

Much better thermal performance - 2.5*C/W (same as the XML2) versus 4*C/W.

Same viewing angle as the original XP-G. 125* versus 115* for the XP-G2. There was some disagreement when the XP-G2 came out of whether or not a wider viewing angle or narrower viewing angle produced more light into the spot of the beam - I will not argue that point here.

The tint CRI binning is right in line with the current suite of available LEDs so it doesn't bother me.

Holy Lumens though.

@~1A a R5 binned XP-G2 will push out 347 lumens.
@1050mA a V4 binned XP-L will push *440 lumens*. A gain of *26.8%*. That is pretty huge compared to the normal 7% binning gains we see.


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## monkeyboy

RetroTechie said:


> Checking the datasheet, I'm reading 150+ lm/W for the cool white, highest output bin. More if you can keep the LED cool. Those are some amazing numbers for a LED this size & at those output levels... oo:
> 
> Looking at the spectrum graph, I'd hesitate to use this for general lighting purposes. But for flashlights: PERFECT!
> 
> With this as a drop-in for XP-G(2), I'm wondering what Cree comes up with as XM-L(2) drop-in... Looks like this might be the new "gold standard" where XP-G2's were used before.



Pretty sure this is using an XM-L2 size die, not XP-G2 size. Nothing new here really, just a smaller package and slightly lower cost.


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## ShineOnYouCrazyDiamond

monkeyboy said:


> Pretty sure this is using an XM-L2 size die, not XP-G2 size. Nothing new here really, just a smaller package and slightly lower cost.



That is an interesting point. I am looking through the documentation and I cannot find an exact spec for the die size but Cree's diagrams do show a larger die on the XP-L. The documentation does specify it as the replacement for the XM-L line of LEDs.

Now just because of that I wouldn't dismiss this LED the way you have. It is still over 25% brighter than a XP-G2 in the same package. It will really require waiting until some XP-G2 lights are swapped with this new LED using XP-G based reflectors that we will see where things stand. I would expect a little bit floodier, but still probably brighter in the spot - but not as bad as a XM-L based reflector would be. Also the fact you can safely drive it up to 3 Amps is pretty cool.

My real question - will the lens be small enough to fit into the Carlco XP based triple optics? Imagine a 9Amp triple in something the size of a Tri-EDC.


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## RetroTechie

ShineOnYouCrazyDiamond said:


> It is still over 25% brighter than a XP-G2 in the same package. It will really require waiting until some XP-G2 lights are swapped with this new LED using XP-G based reflectors that we will see where things stand. I would expect a little bit floodier, but still probably brighter in the spot - but not as bad as a XM-L based reflector would be.


Yeah, the datasheet indicates even a bit higher lumens output than XM-L2 highest output bins. So "XM-L2 performance (and then some), in an XP-G(2) size package" seems like best description for the time being. One thing seems certain: it's not a drop-in fit for XM-L(2) footprints, so upgrading eg. XM-L based lights would probably involve a swap of the LED board, not just the emitter. And possibly reflector too, if an exact beam profile is to be maintained.

Of course we'll need to see some actual lights built using this (or emitter swap), and see how datasheet specs hold up in real life.


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## ShineOnYouCrazyDiamond

Cutter has the cooler tint bin available right now, but I love my neutrals so I'll be holding out another few weeks/months until the 4000K tint becomes available. At that time I will upgrade a few XP-G/XP-G2 lights and try to take comparison beamshots of the process. My hope is that the increase in brightness will outweigh the increase in floodiness of the larger die.

Lights I plan to test upgrades on are: LF2XT, V10R, HDS Clicky. My goto selection of lights.


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## monkeyboy

The naming convention would suggest the larger die. 
e.g. 
XR-*C*, XP-*C* = ~0.5mm^2
XR-*E*, XP-*E*, XP-*E*2 = ~1mm^2
XP-*G*, XP-*G*2 = ~2mm^2
XM-*L*, XM-*L*2, XP-*L*? = ~4mm^2

I think the XP-L must be using the same die as the XM-L2, as the specifications are too close. The XP-L has a few very minor differences in typical values including slightly more lumens at 10W but this could be due to the binning document being published at a later date where small improvements have been made to the fabrication process.


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## Canuke

User "welight" on a different forum, reports that these don't fit XP optics (e.g. Carclo). I infer from this that the dome is a bit bigger than XP-G2. Not really an XP- replacement then.


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## WeLight

we have tried them under Carclo and Ledil triples, no joy,Primary dome too large, not bad with a Regina Reflector but no hot spot. Works ok on a Triple 32mm board with CUTE optic but again no super spot, Will be trying with Khatod PL1672 but its a 35mm single optic but lovely thrower for XPG-2 or XML-2 so Im thinking this will be a nice match
Cheers
Mark


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## ShineOnYouCrazyDiamond

Mark - Thanks for that information. I was afraid of that due to the bigger lens. Even going from XP-G to XP-G2 I had some issues with regular reflectors because of the greater dome size on the lens.

Have you had a chance to upgrade any XP-G2 based lights that use a more standard reflector rather than an optic? I'd be interested in hearing your experiences.


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## Canuke

Me also. 

One thing of interest: the dome looks as if it were actually too big for the footprint, and "trimmed" to fit, resulting in flat faces on four sides. Because of the physics involved, as dedoming aficionados know, that's going to alter the quality of the light coming out of the sides. The first folks to get these into existing reflector setups, especially smooth and mild OP ones, are going to find out that their hotspots are different somehow - possibly XB-D like in their color pattern.

Can't wait for the first beamshots to see whether I'm right.


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## Steve K

I haven't been keeping up with the latest stuff, or even the not-so-latest.... so I'm a bit amazed that they can put 10 watts through this little package and not cook it! 

Does anyone sell stars for use with this package? I can't imagine a hobbyist making their own board that could get the heat out of this package.


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## RoGuE_StreaK

It's the same physical footprint as the XP-G/E/C, so just using their stars.
Which as you say, raises my biggest concern; how are you supposed to get XM-L2 heat out of a thermal pad 1.3mm x 3.3mm, compared to the XM-L2's 2.78mm x 4.78mm??   Sounds to me like direct-to-copper or it'll be toast, seems like a major bottleneck


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## Steve K

same as the XP-G? that's not so awful, I guess. I did make some copper mounts for a few XP-G's a couple of years ago. Pretty low tech, and using crude tools, but it worked when putting 3 watts into the LED. Not sure if I'd have the nerve to put 10 watts through the same size package.


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## ShineOnYouCrazyDiamond

I too have some concerns with the cut side of the lens. I guess only some real world testing will show if it causes any weird beam issues.


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## RoGuE_StreaK

Steve K said:


> same as the XP-G? that's not so awful, I guess. I did make some copper mounts for a few XP-G's a couple of years ago.


Times have changed, now you can buy proper direct-to-copper boards like the copper sinkpads or noctigons, for not much at all.
I guess if you are extracting the heat properly then perhaps it won't build up as much to start with, so may not be such a bottleneck. I don't have any particular reason to try them though, larger XM-L2 is fine for my purposes.


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## Bronco

Is it safe to assume that the surface brightness of this LED will be a pretty close match to the XM-L2?


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## monkeyboy

If you compare the data sheets between the XM-L2 and XP-L and use some extrapolation, the XP-L V5 flux bin is equivalent to the XM-L2 U3 flux bin and V4 is equivalent to U2. The XM-L2 U3 is quite rare and I've only seen it offered in cool/green tints, but you can already get neutral XM-L2 U2 3D , so we'll have to wait and see what bins are available when the XP-L is released. But looking at the preorder options from cutter.au, there are cool V5 bins and neutral V4 bins, so it doesn't look any better than the XM-L2.
My main concern about the XP-L is that the frosted dome will reduce throw, but are these pre-production pictures even accurate? If you look at the pictures of XP-L on PCBs from cutter, the domes look perfectly smooth to me.


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## tstartrekdude

I really wish that Cree would stop changing how they bin LED's, the change in binning temperature made sense but why change the current from 700ma to 1050mh? They even have brightness listed for multiple currents in the documentation but omet the most useful one, the one that would give a direct comparison.


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## degarb

tstartrekdude said:


> I really wish that Cree would stop changing how they bin LED's, the change in binning temperature made sense but why change the current from 700ma to 1050mh? They even have brightness listed for multiple currents in the documentation but omet the most useful one, the one that would give a direct comparison.



I was going to write Cree, "Hey, Dudes! Would it be so hard to list 700 and 350 ma, alongside 1 amp for the xp-l? Cause while it looks most efficient at 500 ma, I am not getting 200lpw (my calc program is buggy)." Then, at end of the last post, my fingers either got cramped, I got too vented, or that ad on top of page diverted my attention.
Hmm. Hey, looks like 4sevens has a new light to check out....


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## mds82

you can always go to http://pct.cree.com/dt/index.html and figure out the bin's of them also. Takes a bit more work but its really useful


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## misterobotique

I got the chance to obtain 2 samples of XP-L reflowed on a classic aluminium star (Cree came yesterday at work).

I took some close-up photos of the sample and thought I will share them with you guys. 

The photos are pretty large so I just post the link:
*3500K and 5000K http://i62.tinypic.com/550x85.jpg*
*3500K face up http://i60.tinypic.com/3356ssw.jpg
3500K inclined http://i57.tinypic.com/25so9oo.jpg
3500K side view http://i61.tinypic.com/20go0h1.jpg

*Hope you like it!


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## monkeyboy

misterobotique said:


> I got the chance to obtain 2 samples of XP-L reflowed on a classic aluminium star (Cree came yesterday at work).
> 
> I took some close-up photos of the sample and thought I will share them with you guys.



Thanks for posting. How would you describe the appearance of the dome? It's hard to tell from the picture. It doesn't look frosted as it does on Cree's website but I'm seeing a slight concentric circle pattern from the light passing through onto the die.


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## misterobotique

The dome is completly transparent, with no trace of frosting.
When I first saw the photo on Cree's website I was a little bit concerned by those concentric circles pattern on the dome but the sample I got at work doesn't seem to have them.
I will have a closer look tomorrow and take some photo if I notice anything.
By the way, the shape of the dome itself is interesting : it's not totaly spherical but it looks like it has been "cut" to feet to size of an XP-G package (as you can see it on Cree's website).


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## ShineOnYouCrazyDiamond

Please post beamshots!  I want to know how these trimmed domes are going to perform in a reflector situation.


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## bshanahan14rulz

I wonder if there may be a stronger forward bias to the light output.


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## ShineOnYouCrazyDiamond

I am more concerned about funky artifacts.


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## bshanahan14rulz

Play that funky high flux white light.. Play that funky high flux light!

Yeah, wonder if instead of a square shaped "corona," maybe this will have an octagonal corona, or a smoother but "wider" transition to spill. I'm guessing these were meant to be packed in side-by-side in tight quarters for a lot of light from a relatively small array. Like for indirect lighting or something like that. But I'm glad to not see those ugly molding circles in the final sample.


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## monkeyboy

misterobotique said:


> When I first saw the photo on Cree's website I was a little bit concerned by those concentric circles pattern on the dome but the sample I got at work doesn't seem to have them.



I was actually referring to _your_ pictures when I mentioned the concentric circles. The light shining through the dome seems to cast a concentric circle pattern on the die which suggests that in fact there might be this pattern on the dome. Concentric circle patterns and cut sides are not necessarily a bad thing though, I mean you have to assume that these Cree engineer guys know a thing or two about designing LED domes. :duh2:


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## Megatrowned

I don't think we need to worry too much about the dome being completely clear. I recently read that scientists have discovered very tiny scales on a species of firefly (on the area that emits the light they make), which allows the light it produces to appear about 50% brighter. Maybe Cree is trying something similar?


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## bshanahan14rulz

Or rather, it might be a means to cope with the color separation issue that XM packaged LED had. I would imagine they can vary the angle of the surface as long as the farthest and closest emitting points on the die are not past the critical angle for reflection/refraction, and I would guess that they have the technology to figure that stuff out to improve color mixing without sacrificing package efficiency.


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## ShineOnYouCrazyDiamond

Why is it I feel like it wasn't anything that technical and they just slapped a lens on there and chopped the sides to fit?


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## RoGuE_StreaK

ShineOnYouCrazyDiamond said:


> Why is it I feel like it wasn't anything that technical and they just slapped a lens on there and chopped the sides to fit?


That's pretty-much how I'm seeing it


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## Canuke

Perhaps that subtle crinkling is there to break things up just enough to mitigate potential artifacts from those flat faces.

The second generation of XM-L and XP-G seem to have mitigated the color separation issue, based on examples I have to hand, so perhaps this is another step in that direction.


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## monkeyboy

In stock now at cutter.

http://www.cutter.com.au/products.php?cat=Cree+XPL

They have them on standard 10mm PCB and 16/20mm Noctigon PCB! 
They also have 3C tint bin (neutral white) in V5 flux bin! (equivalent to XM-L2 U3 3C)

EDIT: I just ordered a bunch of them. Already feeling the buyer's remorse.

EDIT 2: Got email from cutter to say that the items are back ordered, not in stock.

EDIT 3: In stock now!


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## RoGuE_StreaK

monkeyboy said:


> Already feeling the buyer's remorse.


Just think of yourself as an Innovator, getting in before the Early Adopters.
Was there a group of wildly cheering people awaiting you as you exited the virtual building, like there is at such times with Apple?


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## psychbeat

monkeyboy said:


> In stock now at cutter.
> 
> http://www.cutter.com.au/products.php?cat=Cree+XPL
> 
> They have them on standard 10mm PCB and 16/20mm Noctigon PCB!
> They also have 3C tint bin (neutral white) in V5 flux bin! (equivalent to XM-L2 U3 3C)
> 
> EDIT: I just ordered a bunch of them. Already feeling the buyer's remorse.



Thanks for taking the plunge!
Keep us posted on yer results!


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## gunga

No worries. I'll buy some neutrals off of you if your remorse gets too extreme!


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## TnC_Products

I got 20 samples from Cree. Both cool white and warm white. They decided not to send me Neutral white for some reason.  I am trying to figure out what light I want to put this in to test out the beam pattern and any artifacts that might be present in the beam.

If there are no beam shot pictures posted here when I test these out I will post some. I will see if I can do side by side test with XP-G2 and XP-l and then XM-L2 and XP-L.

Need to see if this will fit in my custom XP-G2 reflectors. After seeing the size of the die I am not very hopeful.

Chris


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## monkeyboy

Apparently my Cutter order is backordered, not in stock (grumbles).
EDIT: In stock now!

@ TnC, Yes we'd be very interested to see the results. Thanks for taking the time to do this.


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## monkeyboy

My XP-L's from cutter arrived today!

These are V5 3C bins (equivalent to XM-L2 U3 3C). Illumination supply is also selling cool white V6 bins (emitter only) so I'd say we're getting about 1 flux bin better than the best XM-L2 emitters. Looking at the emitter, yes there is some very light frosting on the dome and a slight concentric circle pattern, although not as much as the pictures on the Cree website make it appear. It's hard to see with the naked eye but you can clearly see it through a magnifying glass. I have upgraded the following lights to the new XP-L:

Jetbeam RRT-2 (with XP-G2)
Jetbeam RRT-2 (with XM-L2)
Spark SD6 (with XM-L)

Unfortunately, I don't have a lux meter to do a throw comparison, but my impression is that the throw is as good as the XM-L2/XM-L or maybe even a little better. Perhaps this is due to the higher flux bin but I don't know. What's important is that it seems to focus perfectly with the original reflector, the frosting and pattern on the dome doesn't seem to affect the throw, and the cut sides don't produce any strange artefacts. 
The colour separation of the XM-L2/XM-L is still there and doesn't seem to have improved. i.e. the light emitted forwards is more blue and the light emitted sideways is more yellow resulting in a yellower hotspot and bluer side spill when used with a reflector. Not a big deal though. Overall, the 3C bin LEDs I received from cutter have a perfect tint. Not too green, not too red.


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## ShineOnYouCrazyDiamond

Thanks for that information Monkeyboy. I'd like to find out a bit more details on the RRT-2 upgrades.

For the one with XP-G2, did the move to XP-L give it a wider spot? Does it throw as far?

For the one with XM-L2, did the move to XP-L give it a tighter spot? Does it throw better?

If you compare both RRT-2 lights (where I assume the reflector is a bit different due to the original sized LEDs) do both beams look exactly the same or is the one from the XP-G2 tighter?

Before and after beamshots to compare the spot/flood would be great if you have them.


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## monkeyboy

ShineOnYouCrazyDiamond said:


> Thank for that information Monkeyboy. I'd like to find out a bit more detail son the RRT-2 upgrades.
> 
> For the one with XP-G2, did the move to XP-L give it a wider spot? Does it throw as far?
> 
> For the one with XM-L2, did the move to XP-L give it a tighter spot? Does it throw better?
> 
> If you compare both RRT-2 lights (where I assume the reflector is a bit different due to the original sized LEDs) do both beams look exactly the same or is the one from the XP-G2 tighter?
> 
> Before and after beamshots to compare the spot/flood would be great if you have them.



OK, so the RRT-2 XP-G2 to XP-L (smooth reflector), the hotspot is definitely wider with less throw, although the overall output has increased.

for the RRT-2 XM-L2 to XP-L (light OP reflector), the difference is harder to see. I think the throw is about the same or a tiny bit better but can't prove it without a light meter. 

My XM-L2 RRT-2 started off as the XM-L version so had a higher drive level to begin with. It's more powerful and throws further despite the OP reflector. Otherwise the XP-G reflector gives a slightly tighter spot.

Sorry, I didn't do any beamshots.


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## m4a1usr

monkeyboy said:


> My XP-L's from cutter arrived today!
> 
> These are V5 3C bins (equivalent to XM-L2 U3 3C). Illumination supply is also selling cool white V6 bins (emitter only) so I'd say we're getting about 1 flux bin better than the best XM-L2 emitters. Looking at the emitter, yes there is some very light frosting on the dome and a slight concentric circle pattern, although not as much as the pictures on the Cree website make it appear. It's hard to see with the naked eye but you can clearly see it through a magnifying glass. I have upgraded the following lights to the new XP-L:
> 
> Jetbeam RRT-2 (with XP-G2)
> Jetbeam RRT-2 (with XM-L2)
> Spark SD6 (with XM-L)
> 
> Unfortunately, I don't have a lux meter to do a throw comparison, but my impression is that the throw is as good as the XM-L2/XM-L or maybe even a little better. Perhaps this is due to the higher flux bin but I don't know. What's important is that it seems to focus perfectly with the original reflector, the frosting and pattern on the dome doesn't seem to affect the throw, and the cut sides don't produce any strange artefacts.
> The colour separation of the XM-L2/XM-L is still there and doesn't seem to have improved. i.e. the light emitted forwards is more blue and the light emitted sideways is more yellow resulting in a yellower hotspot and bluer side spill when used with a reflector. Not a big deal though. Overall, the 3C bin LEDs I received from cutter have a perfect tint. Not too green, not too red.



Since I don't know the reflector sizes in the lights you made changes to, but am reading your comments regarding beam differences, do you have the current measurements at the LED in those lights? The differences (if any) in how they are driven could shed some light on beam disparities. I'm hoping to jump on the XPL train myself but am seeking as much info as possible to know where to start.


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## phantom23

monkeyboy said:


> Unfortunately, I don't have a lux meter to do a throw comparison, but my impression is that the throw is as good as the XM-L2/XM-L or maybe even a little better. Perhaps this is due to the higher flux bin but I don't know. What's important is that it seems to focus perfectly with the original reflector, the frosting and pattern on the dome doesn't seem to affect the throw, and the cut sides don't produce any strange artefacts.


Properly focused XP-L can give 5% more lux/1m than XM-L2, not more. It won't be brighter either.


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## ShineOnYouCrazyDiamond

phantom23 said:


> Properly focused XP-L can give 5% more lux/1m than XM-L2, not more. It won't be brighter either.



I read your statement and the first thing I wanted to write was where you were getting your empirical evidence from to support your claim. Then I brought up the XM-L2 and the XP-L spec sheets from Cree's website. It's very hard to directly compare the flux bins because the XM-L2 is binned at 700mA and the XP-L is binned at 1050mA.

U2 still remains a 300 lumen rating regardless of where the current of binning is at. So U2 XM-L2 and U2 XP-L cannot be compared directly.
Following the Relative Flux curve on the XM-L2 up to 1050mA it appears to be at ~1.4x. So I would factor a U2 bin to be the equivalent of 300 x 1.4 = 420, which is directly equal to a V3.

Comparing the output at the specified currents of 1500ma and 2000mA from the charts:

XM-L2 580 728
XP-L 566 708

So you appear to be right that the XP-L cannot maintain an equivalent output as current rises.

Compared to a XP-G2, the XP-L is significantly brighter though. Doing a comparison of my favorite tint in the 4000K range I can get a XP-G2 in R5 flux and a XP-L in a V4 flux. At the available comparison current of 1500mA:
XP-G2 R5 = 458 lumens
XP-L = 593 lumens

How that compares in the real world I will not be able to tell until I actually get some later this week but an increase of 30% is significant although the gain may not be useful if it's lost in a bigger spot and more flood.


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## monkeyboy

phantom23 said:


> Properly focused XP-L can give 5% more lux/1m than XM-L2, not more. It won't be brighter either.



Yes it is brighter. Look at the cree comparison tool.

http://pct.cree.com/dt/index.html

The V6 bin cool and V5 bin neutral XP-L are equivalent to U4 cool and U3 neutral XM-L2 which are not available anywhere as far as I know. Even at 3 amps the top bin XP-L (V6) is brighter than the top bin XM-L2 (U3).

Where are you getting these figures from anyway?


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## monkeyboy

ShineOnYouCrazyDiamond said:


> the XP-L cannot maintain an equivalent output as current rises.



It's much easier to use the Cree Comparison tool. Yes this is true, but the difference between the equivalent XM-L2 bin is only a few lumens (up to 3 Amps at least). V6 bin XP-L is still significantly brighter than U3 bin XM-L2 at 3 amps. Perhaps it's a different story if you overdrive it to 5A for example.


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## phantom23

monkeyboy said:


> Yes it is brighter. Look at the cree comparison tool.
> 
> http://pct.cree.com/dt/index.html
> 
> The V6 bin cool and V5 bin neutral XP-L are equivalent to U4 cool and U3 neutral XM-L2 which are not available anywhere as far as I know. Even at 3 amps the top bin XP-L (V6) is brighter than the top bin XM-L2 (U3).
> 
> Where are you getting these figures from anyway?


I don't like theory, I prefer practice. I got my figures from another forum where someone already got XP-L V6 and compared it to XM-L2 U2 in the same setup. Results were clear - at the same current output was basically identical (XP-L scored 0,5% less lumens).


If you're going to overdrive it, XP-L V5 becomes less efficient even than XM-L2 T6.


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## monkeyboy

phantom23 said:


> I don't like theory, I prefer practice. I got my figures from another forum where someone already got XP-L V6 and compared it to XM-L2 U2 in the same setup. Results were clear - at the same current output was basically identical (XP-L scored 0,5% less lumens).
> 
> 
> If you're going to overdrive it, XP-L V5 becomes less efficient even than XM-L2 T6.



This is just one person's results and you haven't provided a link so we can examine the testing methodology. There are many different factors that could affect these results. e.g. 
Are the PCB's identical? 
How accurate are the current measurements?
How accurate are the voltage measurements? (Important if you're taking about efficiency)
Did they use a calibrated integrating sphere?

If you don't at least say where you got your figures from and provide a link, then these results have zero credibility.


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## ShineOnYouCrazyDiamond

Whether my calculations from the spec sheets are truly spot on accurate or not, I am completely underwhelmed.

I swapped a 5B4 tinted XP-L into a V10R. The focus with a XP-G reflector was probably about as good as it will get and I was not impressed. A bit bigger spot than the XP-G2 and definitely more flood. The tint was not great and close up to a wall I could catch some square edges just outside the corona.

Compared directly with a XP-G2 V10R with similar reflector the XP-G2 had a brighter spot and nicer beam. Brightness appeared about equal.

Compare to a XM-L2 V10R the spot was a bit tighter but not really brighter.

Tint was just so-so.

I don't see the XP-L as a drop-in replacement for the XP-G2 in flashlights. I think it is more oriented towards more general lighting applications.


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## bshanahan14rulz

I would bet an array of these driven conservatively would make a nice streetlight. But, smaller area of thermal path, makes sense that it doesn't do so well at higher powers I guess.


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## RetroTechie

ShineOnYouCrazyDiamond said:


> I think it is more oriented towards more general lighting applications.


+1

Perhaps... maybe... flashlights is NOT where you should be looking for XP-L's. :thinking:


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## gunga

This is great feedback. Thanks for taking the effort to try these out. I wonder if they would perform better in an optimized reflector. May not be worth the effort though.


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## Kestrel

FWIW, it appears as though Nitroz has had some good results with the new XP-L in a SF U2.
http://www.candlepowerforums.com/vb...ra-XP-G2-mod&p=4460430&viewfull=1#post4460430


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## djozz

I did an output test in my integrating sphere on a XP-L V6 2C (obtained from Illumination Supply) and compared it to a XM-L2 T6 3C (from Fasttech), both mounted on copper Sinkpads. I will just reproduce the graph here. If you like to know how I did the measurements please refer to the other flashlight forum.


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## leaftye

I'm very surprised that it opened up a greater lead at higher currents. With the smaller substrate, I expected bigger gains at lower currents, quickly falling off at higher currents, with a the crossover at ~7.75 amps. Hopefully Carclo puts XP-L optics into production soon.


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## ShineOnYouCrazyDiamond

I don't think comparing a T6 XM-L2 bin to a V6 XP-L bin is a fair comparison. A T6 using the Cree comparison tool looks like it would line up closer to a V2 if you want to do a fair side by side comparison. If you are just comparing what is available then you also need to take into account that the V6 is 4 bins brighter and should be SIGNIFICANTLY brighter across the chart - which it is not.


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## djozz

The test was focused on the new XP-L, the XM-L2 T6 3C was what I had in the spare leds box and I figured that it made a useful comparison, I'm sure you guys are capable of extrapolating the results to a top bin


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## phantom23

ShineOnYouCrazyDiamond said:


> *I don't think comparing a T6 XM-L2 bin to a V6 XP-L bin is a fair comparison*. A T6 using the Cree comparison tool looks like it would line up closer to a V2 if you want to do a fair side by side comparison. If you are just comparing what is available then you also need to take into account that the V6 is 4 bins brighter and should be SIGNIFICANTLY brighter across the chart - which it is not.


Why its not a fair comparison? It turned out that its more than fair! It also prooved that there's something wrong with Cree's calculations and that XP-L isn't more efficient/brighter than XM-L2. More - its less efficient!


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## monkeyboy

phantom23 said:


> Why its not a fair comparison? It turned out that its more than fair! It also prooved that there's something wrong with Cree's calculations and that XP-L isn't more efficient/brighter than XM-L2. More - its less efficient!



All it shows is that a V6 XP-L is brighter than a T6 bin XM-L2 up to 7.5A according to a guy with a home made integrating sphere and that one particular emitter happens to have a higher Vf than the other. An improvised integrating sphere is not an accurate way of measuring these small differences in lumen output as it is not independent of beam pattern. I am grateful to djozz for doing these tests but this is NOT a more reliable source than Cree's own data. 

The other link you PM'ed me showed that a V6 XP-L matches a U2 bin XM-L2 at around 3.8A and so presumably beats it at lower currents.


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## phantom23

Two LEDs with the same die and nearly identical beam patters were tested in the same setup, how on earth the results can be skewed towards one of them?

As you noticed XP-L was very slightly brighter but not more efficient (because of higher Vf). Thing is that based on Cree specs the difference should be quite big and noticeable and here we have another test that shows that it isnt. They cant all be wrong.


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## djozz

monkeyboy said:


> All it shows is that a V6 XP-L is brighter than a T6 bin XM-L2 up to 7.5A according to a guy with a home made integrating sphere and that one particular emitter happens to have a higher Vf than the other. An improvised integrating sphere is not an accurate way of measuring these small differences in lumen output as it is not independent of beam pattern. I am grateful to djozz for doing these tests but this is NOT a more reliable source than Cree's own data.
> 
> The other link you PM'ed me showed that a V6 XP-L matches a U2 bin XM-L2 at around 3.8A and so presumably beats it at lower currents.



I have seen professionals using fancy equipment failing miserably at doing their job, and I have seen people using simple home-made equipment doing brilliant measurements. I think that simply dismissing the above measurements because the sphere is home-made is a bit simplistic.

Building an integrating sphere that is effectively beam pattern independant and gives consistent and lineair readings is not exactly rocket science. With a bit of initial reading, and the build is done with a bit of common sense, and some checks have been done on the performance, these simple home-made spheres do their job well within 1% accuracy and consistancy, while the differences that show in the graph above between the two leds are more like between 5 and 10%. Such a sphere is perfectly adequate to show relative differences between leds or for that matter complete flashlights. Calibration is a different story, getting the sphere within 1% of the actual lumens is more difficult, to be precise 400 dollar difficult for me (spent on having a constant light source -or the sphere- officially calibrated). I have not spent the 400 dollars, so I can not guarantee my sphere within 1% of the actual lumens (as explained in the build thread of the sphere in another flashlight forum)

Same goes for measuring voltages. A simple middle-of-the-road multimeter measures voltage within 1%, the voltage differences between the two leds in the above graph are 5-8%.

Cree's data are as far as I know not produced with the leds on Sinkpads, and do not go above 3A (from which current it is just starting to get interesting  ) , the aim of these measurments is not to reproduce or improve Cree's data (although I really don't mind checking their data  )

There is differences between individual leds that are spec'ed the same. In that aspect the above results of 1 led each can vary a bit. Everyone who is interested in these kind of data knows that that is the case and realises that when interpreting the data. I wonder however if that variance can be expected to be as high as the 0.3V difference found between the two measured leds.


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## monkeyboy

phantom23 said:


> Two LEDs with the same die and nearly identical beam patters were tested in the same setup, how on earth the results can be skewed towards one of them?
> 
> As you noticed XP-L was very slightly brighter but not more efficient (because of higher Vf). Thing is that based on Cree specs the difference should be quite big and noticeable and here we have another test that shows that it isnt. They cant all be wrong.



What other tests are you talking about? 
The first link you PM'ed me doesn't prove any of the claims you initially made now all of a sudden that link is no good but this one is? 
With regards to Vf, it's well known that Cree's LEDs are not Vf binned and can vary by large amounts.


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## Tobias Bossert

djozz said:


> I did an output test in my integrating sphere on a XP-L V6 2C (obtained from Illumination Supply) and compared it to a XM-L2 T6 3C (from Fasttech), both mounted on copper Sinkpads. I will just reproduce the graph here. If you like to know how I did the measurements please refer to the other flashlight forum.



Hi,
before we start discussion upon accuracy of cree product characterisazion tool we should first check for reasonable accuracy of our own measurements.
Djozz, did you checked the accuracy of your equipment against variating spectral pattern?
You compared XM-L2 3C (more red) against XP-L 2C (less red). Can you guarantee that your sensors measure 3C and 2C with the adequate calibration factors? Even more, do anybody know whether the spectral pattern of XM-L2 and XP-L is identical in case of identical colour binning? May be Cree has modified the phosphors too and the spectral pattern is quite different. Identical color bins can be achieved by different spectral patterns which produce similar subjective sensation for human eyes, but may be measured by sensors completely diffrerent, in case the sensors don't use exactly the same spectral sensitivity of the three colors for the human eye.
Tobias


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## djozz

Tobias Bossert said:


> Hi,
> before we start discussion upon accuracy of cree product characterisazion tool we should first check for reasonable accuracy of our own measurements.
> Djozz, did you checked the accuracy of your equipment against variating spectral pattern?
> You compared XM-L2 3C (more red) against XP-L 2C (less red). Can you guarantee that your sensors measure 3C and 2C with the adequate calibration factors? Even more, do anybody know whether the spectral pattern of XM-L2 and XP-L is identical in case of identical colour binning? May be Cree has modified the phosphors too and the spectral pattern is quite different. Identical color bins can be achieved by different spectral patterns which produce similar subjective sensation for human eyes, but may be measured by sensors completely diffrerent, in case the sensors don't use exactly the same spectral sensitivity of the three colors for the human eye.
> Tobias



Hi Tobias, thanks for your questions . Reasonable accuracy is indeed what I am looking for. My concern is not how to obtain the most accurate numbers in the world, in my budget I will never be able to get there anyway, my concern is to get the numbers accurate enough to tell the story. 

About accurate recording of the different wavelengths, of course it is something I worry about, but it is also something that I can not measure easily: if the luxmeter that I use in my sphere was an expensive one (they start at 500+ dollars), it would come with a very good colour filter in front of the sensor, and with the datasheet that told me how well it follows the human eye response to the visible spectrum (the luminosity function that is at the basis of the lux/lumen). In that case I might be able to give a well thought-over answer to the question: how much does it matter that I compared a 2C bin to a 3C bin, will it affect the hight of the curves so much that it leads to different conclusions? My luxmeter however is a relatively cheap chinese one. Undoubtedly the spectral response of this cheap luxmeter will match less with the luminosity function. The luxmeter (a Ceto CT1330B) came with a very vague (nonometers ) and not reliable looking chinese graph, well, let's just show it here:




...that suggests (if we believe that the graph is representing actual collected data) that the meter follows the luminosity function quite reasonable from 490nm onwards, below 490nm funny things happen, it is in a less sensitive colour region, but it is also where the blue spike is in the white leds that we measure.
Sooooo, I don't know how bad it is, and I don't know how to measure it. I only assume that it is not a big deal when comparing tints that are not that far from each other. Only thing I could do is do a test on a XM-L2 T6 2C led and see how much it differs, but then the variation between leds in the same tint and bin category would give another ground for discussion.
My question back is (and it is really something I have not a clue about): there's quite a few here at CPF who have integrating spheres, do they use those colour-response-accurate luxmeters?, is there anyone who has tried to measure it, or is there any data from other sources on how much it matters?

One thing what I would like to add, despite that I really like a good discussion: there is a tendency here (at least with some) when confronted with measurements that are potentially useful, to pinpoint every possible flaw in the method used, however likely or unlikely. And that last bit is what I miss a bit in the discussion: how likely is it that what you see in the data is noise or systematic flaws in the method, and how likely is it, despite every objection that you can come up with, that the data are simply not that far off, and show something that is real?


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## Tobias Bossert

I asked because your results deviate by 15 to 20% from Cree pct.

As far as I can read your measurement curve, you found @3A:
XM-L2 T6 about 1220lm and XP-L V6 about 1270lm

Cree pct gives for Tj=25°C @ 3A:
XM-L2 T6 1048lm and XP-L V6 1226lm

Values of XP-L V6 match good (1270 to 1226), 
but values of XM-L2 T6 don't (1220 to 1048)

Do you have another XM-L2 to reproduce the measurement?


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## leaftye

How does Cree test their LED's? That can explain the difference if they've been using a mcpcb with a dielectric layer under the XM-L2, but then switched to a mcpcb with a direct thermal path for the XP-L. Other tests indicate that Cree datasheets typically represent output based on using a mcpcb with a dielectric layer thermally insulating the LED.


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## WeLight

Tobias Bossert said:


> I asked because your results deviate by 15 to 20% from Cree pct.
> 
> As far as I can read your measurement curve, you found @3A:
> XM-L2 T6 about 1220lm and XP-L V6 about 1270lm
> 
> Cree pct gives for Tj=25°C @ 3A:
> XM-L2 T6 1048lm and XP-L V6 1226lm
> 
> Values of XP-L V6 match good (1270 to 1226),
> but values of XM-L2 T6 don't (1220 to 1048)
> 
> Do you have another XM-L2 to reproduce the measurement?



I agree the T6 Data does not make sense at 3A, sure you didn't have a higher bin XML


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## leaftye

WeLight said:


> I agree the T6 Data does not make sense at 3A, sure you didn't have a higher bin XML



Yes it does. It's the difference between a mcpcb with a dielectric layer under the LED and a mcpcb with a direct thermal path.


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## Tobias Bossert

leaftye said:


> Yes it does. It's the difference between a mcpcb with a dielectric layer under the LED and a mcpcb with a direct thermal path.



No!
I used parameter Tj=25°C, that means, termal path doesn't matter, because flux is measured dynamically (pulses much shorter than termal time constant).
Different pcb technologies could not explain, why the measurement is much above Crees statement under ideal condition.
May be, the device under test was noXM-L2 T6 but U2 at the upper tolerance end - this could explain the difference. 
Therefore it is necessary to repeat the XM-L2 test with another sample. 
Only djozz can do this, because the measurement must be repeated with the same equipment.


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## leaftye

Tobias Bossert said:


> No!
> I used parameter Tj=25°C, that means, termal path doesn't matter, because flux is measured dynamically (pulses much shorter than termal time constant).
> Different pcb technologies could not explain, why the measurement is much above Crees statement under ideal condition.
> May be, the device under test was noXM-L2 T6 but U2 at the upper tolerance end - this could explain the difference.
> Therefore it is necessary to repeat the XM-L2 test with another sample.
> Only djozz can do this, because the measurement must be repeated with the same equipment.



Except actual tests show that it does make a significant difference. You should look for Match's tests. 

You seem to have some good ideas about how to do some reliable tests. Hopefully you're up for doing some tests. Even if your test doesn't match the datasheet and doesn't use a professional integrating light sphere, the data should still be very useful if you document your testing methods well enough. This forum could use some test results from members that spend most of their time here instead of the other forum where members are typically much more thrifty with their flashlight expenditures.


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## Tobias Bossert

leaftye said:


> Except actual tests show that it does make a significant difference. You should look for Match's tests.



Still no!

In case of spezified 'Tj' (juction temperature = die) thermal resistance from 'solder point' to 'heat sink' doesn't matter by definition, because temperature in front of this thermal resistance is used. Under real test conditions this is realized by driving the device under test with short pulses and slow repetition rate, for example 1ms on and 1 sec off. With such a drive situation heating doesn't matter, the average power is about 10 mW only, but you can measure the light output during the on period at about 10 W. So if you use parameter 'Tj' in Cree tool you get the absolut maximum output, which could never be realized with continuous drive. But the result of djozz is higher than this theoretical upper limit.

Your argumentation is still failing in case you use parameter 'Tsp' in Cree tool, because the theramal path is a series circuit of resitance from 'junction' to 'solder point' and of resistance from 'solder point' to 'heat sink'. Only this second part of the path varies for different kinds of pcb.

*So I kindly would ask djozz to cross check his results with a second sample XM-L2.*

As far as I read Cree tool, light output of XM-L2 U3 and XP-L V5 match in the range below 1A. At higher levels XP-L V5 loses some percents with respect to XM-L2 U3, but not so much. At 3A the difference is still under 2%. So I would say, XM-L2 U3 and XP-L V5 are 'alike'. The benefit of XP-L is that you can get even V6 bins, whereas there is no U4 bin announced for XM-L2.


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## djozz

Perhaps it was not the best of ideas to post just the graph here while most of the discussion on the tests is done and the method used is accounted for in another flashlighforum (however easy it is to find it, hint: my username over there is djozz). But there sure is a crowd here that pays attention to details  . 

I am a flashlight modder. The reason I do emitter tests is to provide practical information for people who are considering using the leds in flaslight builds. For them what they first want to know when a new emitter hits the market is (at higher currents than the manufacturer has data for, and in real life, and on copper boards) voltage data and things like: at what current maximum output is reached (on a side note: for my builds I aim for 80% of max output). I explained above (and on the other forum) my current and voltage readings are pretty reliable and the optical properties of my sphere are good, but the least reliable parameter in my tests (because it is just not easy to get it right without spending a lot of money) is the output calibration of the sphere. For a flashlight builder, precise lumen output of a emitter is nice to know, but more interesting than that are comparisons to leds that are already out there: how much better is it? I think my sphere is within 7 or 8% of real lumen output (I really like to be more precise but I can't guarantee that), but output consistancy relative to the next emitter tested I think is closer to 1%. Another -I think less influential- parameter that I can not guarantee (or measure) is, as discussed above, that my luxmeter follows the luminosity function for all wavelengths. For theoretical discussions, like those that are happening here this is food for lots of doubts, a flashlight builder will care much less (I think).

I did not check my results with the Cree characterisation tool. Never thought about doing that because what I want to know about the XP-L is not available the through the Cree tool: what happens at high currents? (So at least I was not biased by what I should find when I did the tests  ). I checked the tool now (as Tobias did), and indeed my XM-L2 numbers agree with a U3 bin (at 25degC junction temperature: at 3A my cooled copper mount could very well have kept the junction temperature close to room temp). I'd rather have the XP-L results agree with the tool than the XM-L2 results; the XP-L was bought from Illumn.com, I really trust their bin claims, while the XM-L2 was bought from Fasttech, I do not know how much their bin claims can be trusted, although getting a U3 bin when a T6 bin was ordered is not the first thing that comes to my mind LOL. Only thing I can say is that I can't think of how I could have done something different when measuring the XM-L2 emitter compared to how I measured the XP-L: the measurements were carefully done, right after each other on the same equipment that before and after the test series gave within 1% the same readings on some reference lightsources that I use.

I have a second XP-L V6 2C led (I destroyed the first one in the above test), it was next to the first one in the same reel. I am curious how different the result will be, so I will do the exact same output test on it one of these days (I will report here and there). I have no XM-L2 U2 2C led to test next to it as Tobias requested. The only source I trust that had it is intl-outdoor, but they are sold out (Mouser/Digikey have way too high shipping costs to the EU). So I'm afraid that I will not do that test any time soon. Only thing I can do is: I have one more of those XM-L2 T6 3C leds from Fasttech, I could test that one, but that will give limited extra information/assurance for the discussion going on.

BTW, I really wouldn't mind, and will be curious about the results, if someone else than me does an output test on this XP-L led as well, so that my work can be checked/compared....


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## psychbeat

^^thanks for all of the effort!


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## wildstar87

WeLight said:


> we have tried them under Carclo and Ledil triples, no joy,Primary dome too large, not bad with a Regina Reflector but no hot spot. Works ok on a Triple 32mm board with CUTE optic but again no super spot, Will be trying with Khatod PL1672 but its a 35mm single optic but lovely thrower for XPG-2 or XML-2 so Im thinking this will be a nice match
> Cheers
> Mark



I'd be interested in knowing if they work under the Khatod 7 up XP-G optics


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## WeLight

wildstar87 said:


> I'd be interested in knowing if they work under the Khatod 7 up XP-G optics



nope


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## leaftye

Like I said, it would be nice to see someone here doing some tests to test the tests. That's how science works. Thank you Match and djozz for actually testing these emitters.


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