# Cree XM-L is a year old now; what next?



## flashflood (Jul 16, 2011)

Not to be greedy or ungrateful, but... It seems like the pace of LED improvements has stalled a bit, doesn't it?

The XM-L is about a year old now, and T6 remains the brightest widely available flux bin.

Luminus has not moved the ball since the SST-50 and SST-90, which are a couple of years old. (The CSM-360 isn't what I mean by new; it's really just a 4 x SST-90 package. The point is, same emitter technology.)

Ditto the rest of the field, as far as I can tell: Seoul P7, etc.

So are we on the brink of a wave of new products, or are we stuck because it's getting harder to improve?

We know that Cree has 231 lm/W in the lab, but how far is this from production?

Anyone have the inside scoop on this? BTW, I get LEDs Magazine and even there it's been awfully quiet lately on the fundamental technology front.


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## Harold_B (Jul 16, 2011)

I think you might run into an information roadblock since inside scoop often means there's also a nondisclosure in place. Some NDAs are so restrictive that once signed it can't be mentioned that one is working with that company let alone anything about new technology. Getting news beyond the industry mags that have access will be a challenge. Not to say that word won't get out sooner or later!


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## easilyled (Jul 16, 2011)

I think XM-L's are here to stay for a good while longer. U2 bins are becoming much more available now.
The XM-L seems an excellent product and I'm not in a hurry for anything to supercede it.
Having to upgrade all one's lights every time a new and better product comes out is a PITA.


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## deadrx7conv (Jul 16, 2011)

I'd like to see higher output bins on all the LEDs mentioned here. 

And, more availability of higher-CRI choices too in warm, neutral, or daylight white. 

SST-50 or SST-90 with 90+CRI, 85CRI... 
P7 D-bin has been out a while. Where is the E-bin, or a higher CRI version? 
MC-E is available in N-bin. But, that LED isn't mentioned much here anymore. What about higher CRI?

How about a quad XM-L package for those that want 4000lm? 

They should also rename the "XM-L" or the "XM-L EasyWhite". Using "XM-L" in two different LEDs wasn't too smart of their marketing department. Its not like we ran out of letters in the alphabet. The "EasyWhite XM-L" looks like a quad XP-E(?) . 

The 231lm/w is great for bragging but is useless without CCT and CRI.


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## MichaelW (Jul 16, 2011)

Cree should go smaller. They need a 3mm^2 LED in the xm package.


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## richpalm (Jul 16, 2011)

deadrx7conv said:


> SST-50 or SST-90 with 90+CRI, 85CRI...
> P7 D-bin has been out a while. Where is the E-bin, or a higher CRI version?
> MC-E is available in N-bin. But, that LED isn't mentioned much here anymore. What about higher CRI?
> 
> How about a quad XM-L package for those that want 4000lm?



I think all of these have been overshadowed by the XM-L. The couple of SST's that I tried were blown away by the XM-L. With a quad setup, what would you do with heat/amperage in a not-monster sized package?

The difference between now and the Luxeon days is that modern LED's are bright enough in flashlights to _see_ with for a change, even for me, not like a green or purple Luxeon that had to be upgraded every time a newer setup came along. So I wonder if there will be a plateau for awhile.

Rich


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## jtr1962 (Jul 16, 2011)

I'm sure in the next few years we will see further efficiency improvements as lab research knowledge makes it to the production line. I've little doubt though that future efficiency increases will be smaller, and come at longer intervals. The reason is a richpalm alludes to-LEDs are plenty _good enough_ for a whole host of practical uses at their present state of development. There just isn't as much immediate need to improve them greatly in order to facilitate adoption. LEDs have all but taken over portable lighting applications, for example. And they're starting to work their way into general lighting. I think what we'll be seeing will be more evolutionary than revolutionary.


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## PCC (Jul 16, 2011)

MichaelW said:


> Cree should go smaller. They need a 3mm^2 LED in the xm package.



Yes! That's what I want to see. Not only that, but, how about an XP-E sized die on an XM package for the throw junkies? Imagine being able to push 2A through an XP-E sized die or 2.5A through an XP-G sized die.


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## radioactive_man (Jul 17, 2011)

The XM-L with its 160 lumens per watt has come a little earlier than Haitz' Law predicted. We may have reached a plateau, or Haitz' Law may need revision.

Let me attempt a quick and dirty revision of Haitz' law: When I got interested in flashlights the XR-E (released october 2006) was the hottest thing in town. This LED had a maximum efficacy of around 85 lumens per watt (someone please correct me, if this is wrong). The XM-L T6 has a max. efficacy of 160 lumens per watt and was released in april 2010, which roughly corresponds to a 88% increase in efficacy in 43 months. This is equal to an increase of 19.3% per year. Cree seems to have already broken the 200 lm/W barrier, so I expect to see LEDs of this efficacy within a year. This prediction agrees with my model, which predicts 228 lm/W two years after the release of the XM-L. However I still think that the development of the XM-L marks a plateau in development, and I don't believe we'll see hotter emitters until about a year from now.

I have an MSc in math and a minor in physics, and I've just extrapolated from a model based on two arbitrarily chosen data points. Somebody please kill me 

EDIT: And by the way, since the theoretical max. efficacy of a white LED is around 300 lm/W, this model breaks down in a few years.


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## MichaelW (Jul 17, 2011)

PCC said:


> Yes! That's what I want to see. Not only that, but, how about an XP-E sized die on an XM package for the throw junkies? Imagine being able to push 2A through an XP-E sized die or 2.5A through an XP-G sized die.


 
I think the smallest die that can be utilized, without making too much changes is the xp-g's [ez1400]. See the spacing of the triple bond wires. Still Cree could rate that at 2 amps, and the 3mm^2 at 2.5 amps.


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## OneSingularPerson (Mar 25, 2012)

It has been 8 months since the last post in this thread. Any new info or speculation?


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## csshih (Mar 25, 2012)

OneSingularPerson said:


> It has been 8 months since the last post in this thread. Any new info or speculation?



XP-E HEW, XT-E White, XB-D. Just check Cree's Press Releases. http://www.cree.com/press/pressreleases.asp

C


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## flashflood (Mar 26, 2012)

csshih said:


> XP-E HEW, XT-E White, XB-D. Just check Cree's Press Releases. http://www.cree.com/press/pressreleases.asp
> 
> C



But still no XM-L successor.

At the time of its introduction, the XM-L was roughly 2.5 times the output of the XP-G and about 20% more efficient. An equivalent technology leap today would be a new emitter with 3.0 Vf, nominal output 1000 lumens @ 2A (170 lm/W), maximum output 2500 lumens @ 6A (140 lm/W). This does not seem out of the realm of possibility given that Cree has had 231 lm/W in the lab for about a year now.

I want my
I want my
I want my MT-V!


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## FPSRelic (Mar 26, 2012)

I heard that laser light was the new black in lighting technology. At least, that's what BMW thinks

http://www.autoguide.com/auto-news/2011/09/bmw-to-replace-led-lights-with-laser-headlights.html


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## easilyled (Mar 26, 2012)

FPSRelic said:


> I heard that laser light was the new black in lighting technology. At least, that's what BMW thinks
> 
> http://www.autoguide.com/auto-news/2011/09/bmw-to-replace-led-lights-with-laser-headlights.html



Interesting, but the OP was asking about LED improvements, this being the LED section, rather than a completely different form of lighting technology.


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## csshih (Mar 26, 2012)

flashflood said:


> But still no XM-L successor.
> 
> At the time of its introduction, the XM-L was roughly 2.5 times the output of the XP-G and about 20% more efficient. An equivalent technology leap today would be a new emitter with 3.0 Vf, nominal output 1000 lumens @ 2A (170 lm/W), maximum output 2500 lumens @ 6A (140 lm/W). This does not seem out of the realm of possibility given that Cree has had 231 lm/W in the lab for about a year now.
> 
> ...


Your what?

Tech does not scale linearly, nor does Cree soley cater to the flashlight market. I would say that Cree is focusing more on the fixed lighting market as they've been releasing more and more high voltage emitters.
See: XT-E HV, XM-L EasyWhite, MT-G, MP-L, CXA2011, ML-C, ML-E, MX-3S, MX-6S... yeah. 
In fact, as we start getting ridiculously lower and lower Vf of LEDs, I bet Cree will purposefully put out higher voltage options to keep efficiency levels optimal.

Anyways - the fixed lighting market will always be much bigger than the flashlight market for obvious reasons. Cree isn't a non-profit organization.



FPSRelic said:


> I heard that laser light was the new black in lighting technology. At least, that's what BMW thinks
> 
> http://www.autoguide.com/auto-news/2011/09/bmw-to-replace-led-lights-with-laser-headlights.html



For one - that article is terribly misleading. PR probably wrote it and you know how that gets. 
In a nutshell- 

They are pointing 405nm lasers at a phosphor (instead of blue leds at a phosphor).

However, the numbers that they quoted (100lm/W vs 170lm/w of laser light efficiency), is almost comparing apples to oranges. 
Their 100lm/w rating (which is a slightly outdated in the first place) is (probably, I can't predict from what sort of strange places PR pulls "competition" numbers from) a relatively honest figure,
but their 170lm/w rating is complete nonsense (please correct me if I'm wrong). From personal testing, I'm only getting 10-20% efficacy from a 405nm diode (~500mW in, 60mW out), and that's *before - so assuming they have some super premium LDs, I doubt it'll be higher than 20-30%.

Alright, now let's take a look at Cree's current Royal Blue emitters(the base of white emitters). Something modern, in this case the XT-E. at 1A it consumes approximately 3.25W (eyeballing graphs)- and (I'll choose a lower bin to not make BMW PR look bad) and puts out... 1.2W. that's 37% for a non super premium bin emitter (electrical efficiency)

Now, we already established that current incoherent sources are much more efficient - so how did the PR department get their super high 170lm/w figure?

From this information, it seems that their rep was quoting the lm/w figures of the led correctly, but was quoting the lm/w figure of the phosphor conversion of the laser.

I could be terribly wrong, it won't be the first, but BMW isn't a laser company. I doubt that they'll come out with anything super groundbreaking with laser tech.

Craig


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## FPSRelic (Mar 26, 2012)

easilyled said:


> Interesting, but the OP was asking about LED improvements, this being the LED section, rather than a completely different form of lighting technology.



True, so I guess I should clarify by saying that the linked document shows that the reason LED technology has not improved greatly recently is because its reaching the limit of its boundaries, and that a newer technology may be around the corner that replaces led's, just like led's replaced incan.


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## csshih (Mar 26, 2012)

FPSRelic said:


> True, so I guess I should clarify by saying that the linked document shows that the reason LED technology has not improved greatly recently is because its reaching the limit of its boundaries, and that a newer technology may be around the corner that replaces led's, just like led's replaced incan.



not at all, LED tech is still improving greatly, especially with Cree finally using thin film and remote phosphor.

Craig


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## slebans (Mar 26, 2012)

flashflood said:


> But still no XM-L successor.



Last week I read an interview with someone from Cree management. He stated that the XT-E LED would take them to 200 lumens per watt. When I tried to post this info the LED forum was down. I cannot remember OTTOMH where I found this statement. 

Stephen Lebans


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## csshih (Mar 26, 2012)

Currently available XT-E/XB-Dss do around 180 lm/w at low drive levels  as newer bins come out - I'm certain they'll hit 200lm/w.

Unfortunately, they don't do so well in flashlights do to the phosphor distribution (in the dome), and the multifaceted flip chip die.

Craig


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## FPSRelic (Mar 26, 2012)

csshih said:


> not at all, LED tech is still improving greatly, especially with Cree finally using thin film and remote phosphor.
> 
> Craig



Apologies

I didn't see your post before I posted. I'll leave the discussion to more knowedgable people on the subject than myself


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## easilyled (Mar 26, 2012)

FPSRelic said:


> True, so I guess I should clarify by saying that the linked document shows that the reason LED technology has not improved greatly recently is because its reaching the limit of its boundaries, and that a newer technology may be around the corner that replaces led's, just like led's replaced incan.



If you have been following led advancement in technology as long as I have, you'd know that huge leaps in efficiency have been followed by flatter periods of consolidation. Think of a step-pattern graph with efficiency being the vertical axis and time being the horizontal axis.

There have been several giant leaps followed by lulls and there is absolutely no evidence whatsoever to suggest that this won't continue for many more years to come.


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## csshih (Mar 26, 2012)

FPSRelic said:


> Apologies
> 
> I didn't see your post before I posted. I'll leave the discussion to more knowedgable people on the subject than myself



sorry, I came off as a bit grumpy when I posted!
LED tech has come a long way since the luxeon craze:

I was planning on writing up a more comprehensive/explanatory led emitter index but haven't had the time.





Top Row left to right: *Luxeon Lux I LD (low dome)*, Luxeon Lux III, *Cree XR-E*, Philips LumiLEDs Luxeon K2 TFFC(philips bought luxeon), *Cree XP-G* (oops, that xr-e and k2 should be swapped.)
Respectively, *1W, 45 lm* (all figures are rough), 3W, 90 lm, *3.5W, 255lm*, , 5.7W, 300lm, *5.25W, 460lm*

Bottom Row: *Luxeon LuxV*, Seoul SSC P7, *Cree MC-E*, Cree XM-L. (the first three are quad dies  )
*4.8W, 120lm*, 10W, 700lm, *9.5W, 750lm*, 10W, 910lm.

soon to be added: Cree XB-Ds 

Also note: the SSC P7 uses Cree chips (and so does the ssc p4, not pictured)

Craig


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## ledstein (Mar 26, 2012)

Yes, XM-L is old and from looking at the newer MT-G i just hope we get a LED that handles heat much better. If you go deep down into the datasheets there is a graph that shows out lumen flux is affected by heat. As we are mostly hobbyists without any lab equipment we really need to care how a LED behaves when is hot because that flux its is what we actually get.

The XM-L flux goes down to 82% when working at 100C junction temperature...






Anyway until the new Cree LED comes (Light and Building is near, maybe we know then) we can enjoy the drop in prices for the XM-L. Now you can even buy one for as low as 4.90€ as i see on this shop: http://www.ledrise.com/leds/high-power-leds/

Any of you found anything cheaper?


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## ledstein (Mar 26, 2012)

I dont seem to be able to upload the chart image with the flux change at 100C, anyway, here is the link:

<br>



<br><br>


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## Kinnza (Mar 26, 2012)

If I remember well, Haitz article stated a trend of doubling performance/cost each 18months, and not a constant increase on performance, as we all know (Haitz included) the physical limits of energy conversion into visible light. For many years, LED manufacturers were focused on increasing the performance of LEDs, in order they can compete with other lighting technologies and goes getting into market niches. But once they have reached the 150lm/W figure, now they are focused of reducing prices at the same trend they increased performance before.

Until now, price per LED unit of a given power has dropped very little. Instead, the manufacturers offered a new device emitting more light, but at give or take the same price. It has been a slow decline in price with time, but very small compared with the increase in light emission. Now the focus is on offering the same amount of light at lower prices, and last releases of all main manufacturers clearly points to cheaper packages.




csshih said:


> For one - that article is terribly misleading. PR probably wrote it and you know how that gets.
> In a nutshell-
> 
> They are pointing 405nm lasers at a phosphor (instead of blue leds at a phosphor).
> ...



I bet I know where that false figure came from. In one of the articles about laser converted white light which arises some months ago, there was a claim of a 70% improvement on light output per burned watt, but on very special conditions which may appear on car headlights: very high current density on the chips and very high power density on the board. On that conditions, LEDs suffer a strong decrease on efficiency, while lasers not, and thus when needed a powerful beam of light, on current state of the art of both technologies, laser converted white may be advantageous. 

That situation just happen on conditions where LEDs gets low efficacy (not cited directly on the article) due the operating conditions.

The author of the article surely saw that figure of 70% improvement, took the typical efficacy of white LEDs as reference and calculated the supposed laser converted efficacy. Obviously, it gets a false figure, as the comparison surely was performed with LEDs emitting 50lm/W as best.


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## saabluster (Mar 26, 2012)

csshih said:


> Unfortunately, they don't do so well in flashlights do to the phosphor distribution (in the dome), and the multifaceted flip chip die.
> 
> Craig


Mine don't have phosphor in the dome. Seems people have been confused about this for some time. The phosphor is just applied across the entire surface of the substrate.


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## csshih (Mar 26, 2012)

saabluster said:


> Mine don't have phosphor in the dome. Seems people have been confused about this for some time. The phosphor is just applied across the entire surface of the substrate.



for both the XT-E and XB-D? I haven't gotten my hands on those yet to check myself. how do they distribute the phosphor over the funky die?

Craig


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## saabluster (Mar 26, 2012)

csshih said:


> for both the XT-E and XB-D? I haven't gotten my hands on those yet to check myself. how do they distribute the phosphor over the funky die?
> 
> Craig


Well I don't have those either but they appear to employ the exact same deposition as the HEW which I have torn apart and examined.


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## ledstein (Apr 19, 2012)

Whats next?

Cree XB-D, Zhaga like modules, Mt-G II
Philips K 4 to 24 UP

details here: http://www.candlepowerforums.com/vb...t-LED-fair-Cree-Nichia-Philips-Seoul-new-LEDs


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## bose301s (Apr 22, 2012)

csshih said:


> not at all, LED tech is still improving greatly, especially with Cree finally using thin film and remote phosphor.
> 
> Craig


You realize LEDs were thin film from day 1 right?


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## RoGuE_StreaK (Apr 23, 2012)

Huh, just received an email from Cree saying that my XM-L sample has been posted... _three months after the sample order was approved_!! Had just given up and ordered some from LedRise only a few days ago!


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## csshih (Apr 25, 2012)

bose301s said:


> You realize LEDs were thin film from day 1 right?



forgot the flip chip, duh!

Craig


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## happyguy82 (Apr 26, 2012)

Ahh! I didn't realise the XM-L was over a year old already. This means that when SureFire releases their upcoming 500lumens lights such as the DM2, it may not be using the best LED on the market.


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## SemiMan (Jul 28, 2012)

Actually back thinned which is probably more accurate is new for power LEDs developed by Osram an licensed to Cree and Lumileds and others. New being years.


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## RichLee (Jul 29, 2012)

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Built on the revolutionary SC³ Technology Platform, the XP-G2 LEDs combine high light output, reliability and efficacy to deliver up to 151 lumens per watt at 350 mA, 85°C or 165 lumens per watt at 350mA, 25°C in cool white (both at 6000K). In warm white (3000K), the XP-G2 LED delivers up to 133 lumens per watt at 350 mA, 85°C or 145 lumens per watt at 350mA, 25°C. The SC³ Technology Platform leverages Cree’s advanced silicon carbide technology, features advancements in LED chip architecture and phosphor and showcases a new package design to deliver the most advanced lighting- class LED components in the industry.
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*


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## flashflood (Jul 30, 2012)

And this thread is now a year old, which makes the XM-L over two years old!

The XP-G2 and MT-G2 are good, but there's still no hint of an XM-L successor. Cree has poured a ton of money into their new silicon carbide platform, but this doesn't appear to be delivering (significantly) more lumens or (at all) better color, just lower cost -- which is great for commercial lighting, but not as relevant for us. I know, I know, we don't matter -- but I really thought we'd be talking about the XJ-Q by now. And complaining that when Cree released the W2 flux bin, it looked a bit green compared to the trusty old V5 and V6.


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## rambo180 (Jul 30, 2012)

similar thread:

http://www.candlepowerforums.com/vb...-in-18650-flashlights-and-LED-chip-technology!


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## mds82 (Jul 30, 2012)

I've heard there will be a XM-L2 coming out soon as well.


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## bshanahan14rulz (Jul 30, 2012)

I'd rather see a smaller chip with the same output of the XM-L, even at the cost of a funky optical source like the DA series


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## fyrstormer (Jul 30, 2012)

What's next? Hopefully something that's easier to focus. The XM-L requires an annoyingly large reflector to get a good beam. The XP-G was just about perfect for pocket-flashlight use.


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## yliu (Jul 31, 2012)

fyrstormer said:


> What's next? Hopefully something that's easier to focus. The XM-L requires an annoyingly large reflector to get a good beam. The XP-G was just about perfect for pocket-flashlight use.



Hence the XPG2


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## fyrstormer (Aug 2, 2012)

yliu said:


> Hence the XPG2


Yes, though I've heard the non-flat die in the XPG2 is harder to focus than the XPG1.


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## bshanahan14rulz (Aug 2, 2012)

As it turns out, the XP-G2 is a flip chip, much like rebels. So it will be just as easy to focus, with no bond wires or anode grid to get in the way.


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## easilyled (Aug 2, 2012)

fyrstormer said:


> Yes, though I've heard the non-flat die in the XPG2 is harder to focus than the XPG1.



Who from and what were their justifications?


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## bose301s (Aug 2, 2012)

easilyled said:


> Who from and what were their justifications?


I think he's getting XP-G2 and XT-E mixed up.


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