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Thread: Cree XM-L2 Finally announced

  1. #31
    Flashaholic* BenChiew's Avatar
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    Default Cree XM-L2 Finally announced

    Quote Originally Posted by Gunner12 View Post
    Read the data sheet, the lumen output at 700 mA, 1 A, 1.5A, and 2A are all on there. Both data sheets too.
    Thanks. Looks like nearly similar to one another.

  2. #32
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    Default Re: Cree XM-L2 Finally announced

    If they claim it's double the lumens per dollar compared to the XM-L, and the lumens haven't increased all that much, I guess that can be interpreted as meaning there'll be a significant price drop?

    That said, the XP-G2 seemed to initially be cheaper at Cutter than the XP-G, but it's now definitely more expensive.

  3. #33
    Flashaholic* bshanahan14rulz's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Is the die larger? Why are people saying it will put out more light but not throw as well?
    Last edited by bshanahan14rulz; 12-12-2012 at 08:13 AM.

  4. #34
    Flashaholic* uk_caver's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by RoGuE_StreaK View Post
    If they claim it's double the lumens per dollar compared to the XM-L, and the lumens haven't increased all that much, I guess that can be interpreted as meaning there'll be a significant price drop?
    I think it's a maybe historic comparison.

    "..and double the lumens-per-dollar of the original XM-L"

    How much was the XM-L when it first came out?

  5. #35
    *Flashaholic* easilyled's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by bshanahan14rulz View Post
    Is the die larger? Why are people saying it will put out more light but not throw as well?
    Which people?
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  6. #36
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    Default Re: Cree XM-L2 Finally announced

    Data sheets say the "old" XML does 1040 lumens at 10w.
    And the "new" XML2 does 1052 lumens at 10w.

    That doesn't seem so revolutionary to me.
    Last edited by twl; 12-12-2012 at 11:30 AM.
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  7. #37
    *Flashaholic* Gunner12's Avatar
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    Default Re: Cree XM-L2 Finally announced

    I think the XM-L's ratings were at 25C while the XM-L2s are at 85C, so if you tested the XM-L2 at 25C like the original XM-L, there should be a larger improvement.

  8. #38
    Flashaholic* BenChiew's Avatar
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    Default Cree XM-L2 Finally announced

    Cree should do their spec sheet based on some standard parameters. At
    least it will be easy to compare between emitters.

  9. #39

    Default Re: Cree XM-L2 Finally announced

    186 lumens per watt is a decent jump. After getting my first Quark light with a 165 lumen per watt XP-G2 l.e.d., I think I'll wait awhile before getting another high end light. I'd like to see a light at least in the 200 lumen/watt range before I blow more money on another big purchase. Cree has lab tested l.e.d.s in the 250+ lumen range now and with their lower cost SiC l.e.d.s, production is going to skyrocket, costs are going to decrease, and research and development are going to produce better products at an excellerated rate to keep ahead of the competition. I don't think I'll have to wait more than a year to get 200+ lumen/watt l.e.d.s (probably 3-6 months).

  10. #40
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    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by Hooked on Fenix View Post
    I don't think I'll have to wait more than a year to get 200+ lumen/watt l.e.d.s (probably 3-6 months).
    I fully agree. 2013 should be the year we finally see production 200 lm/W LEDs. It seems Cree's production usually lags their lab results by 3 years or so. That should mean 250+ lm/W by 2015.

  11. #41
    Flashaholic* Sinjz's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Could someone please help me understand how the XM-L2 is an improvement on the XM-L? I'm not great at reading these spec sheets, but from what I can tell it looks like the XM-L2 Forward voltage is a hair less at any given current, but it also seems to give up a few lumens in exchange. Everything else seems to be pretty much the same. I don't get it. what am I missing?

  12. #42
    Flashaholic* uk_caver's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Look at the datasheet (linked earlier)
    A T6 XM-L produces >=280lm@700mA at 25C
    A T6 XM-L2 produces >=280lm@700mA at 85C and >=318lm@700mA at 25C, so ~13% more light for the same bin and temperature.

  13. #43

    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by Sinjz View Post
    what am I missing?
    You're missing the discussion that happens virtually on every page of these XP-G2/XP-E2/XM-L2 announcements.

    The new generation Cree LEDs are rated at 85C junction temperature, while the previous generation is rated at 25C. When a LED gets hotter its performance drops. Cree has changed its rating policy to better account for real-world usage scenarios, since running a LED at 85 degrees is much more common than at room temperature. Cree did not retroactively re-rate its 1st gen LEDs, so you get the disparity.

    To correct for the difference in temperature you should decrease the output of 1st gen LEDs by some 13..16%. The rule of thumb is that a 2nd gen LED of the aforementioned families is roughly two flux bins ahead of the 1st gen; i.e. an XM-L2 T6's output and efficiency is roughly identical to XM-L U3 (bins go T6 -> U2 -> U3). The average performance improvement is around 15%, to give a rough estimate.

  14. #44
    Flashaholic* Sinjz's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by uk_caver View Post
    Look at the datasheet (linked earlier)
    A T6 XM-L produces >=280lm@700mA at 25C
    A T6 XM-L2 produces >=280lm@700mA at 85C and >=318lm@700mA at 25C, so ~13% more light for the same bin and temperature.
    I assumed the XM-L was tested at 85C straight across, so everything looked so similar. Why did they change?

  15. #45
    Flashaholic* Sinjz's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by moozooh View Post
    You're missing the discussion that happens virtually on every page of these XP-G2/XP-E2/XM-L2 announcements.

    The new generation Cree LEDs are rated at 85C junction temperature, while the previous generation is rated at 25C. When a LED gets hotter its performance drops. Cree has changed its rating policy to better account for real-world usage scenarios, since running a LED at 85 degrees is much more common than at room temperature. Cree did not retroactively re-rate its 1st gen LEDs, so you get the disparity.

    To correct for the difference in temperature you should decrease the output of 1st gen LEDs by some 13..16%. The rule of thumb is that a 2nd gen LED of the aforementioned families is roughly two flux bins ahead of the 1st gen; i.e. an XM-L2 T6's output and efficiency is roughly identical to XM-L U3 (bins go T6 -> U2 -> U3). The average performance improvement is around 15%, to give a rough estimate.
    I haven't read any of those other threads, so thanks for the info!

  16. #46

    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by Sinjz View Post
    I assumed the XM-L was tested at 85C straight across, so everything looked so similar. Why did they change?
    Because 85C is much more realistic.

  17. #47
    Flashaholic* uk_caver's Avatar
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    Default Re: Cree XM-L2 Finally announced

    I do wonder if it might have been clearer if they'd switched to a new output binning description at the same time - presumably they're not planning on repeatedly changing the temperatures they bin at, so it would likely have been a one-off change.

  18. #48
    Flashaholic* BenChiew's Avatar
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    Default Cree XM-L2 Finally announced

    From now forth, I hope CREE will report their future emitters using the 85C standards. Makes it easier and more apparent for us.

  19. #49

    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by bshanahan14rulz View Post
    Is the die larger? Why are people saying it will put out more light but not throw as well?
    Nobody is saying that. How are you getting that from what is being said?

    The XM-L2 is going to throw 20% better (barely noticeable) because it is 20% brighter in the same optical package as before. The reason some here including myself are talking of viewing angles and being disappointed with them is because is because the XP-G2 got a bigger optic with a narrower viewing angle, thus leading to a 50% bump in lux, something that was sadly not repeated.


    Quote Originally Posted by Benchiew
    From now forth, I hope CREE will report their future emitters using the 85C standards. Makes it easier and more apparent for us.


    Why do you hope that? There is nothing to have to hope for, Cree said they were moving to the 85C being standard and that is what they have done.

  20. #50
    Flashaholic* BenChiew's Avatar
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    Default Cree XM-L2 Finally announced

    And where did you see CREE saying that?

  21. #51
    Flashaholic* uk_caver's Avatar
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    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by tstartrekdude View Post
    he XM-L2 is going to throw 20% better (barely noticeable) because it is 20% brighter in the same optical package as before. The reason some here including myself are talking of viewing angles and being disappointed with them is because is because the XP-G2 got a bigger optic with a narrower viewing angle, thus leading to a 50% bump in lux, something that was sadly not repeated.
    I hadn't realised the XP-G/XP-G2 beam shape difference had effects that large (presumably ~25-30% lux boost to add to 15~20% efficiency gains?)
    What kind of optic was that with (reflector, TIR or aspheric)?

    Scaling/overlaying the spatial distribution curves on the same scale shows what looks like a small difference - XP-G maybe being 2 or 3% brighter over much of the off-axis viewing angles - it's surprising that such a seemingly small change has such an effect.

  22. #52
    Flashaholic langham's Avatar
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    Default Re: Cree XM-L2 Finally announced

    So do any of you have any predictions for improvements that this led would give to the more high end lights that use the U2 bin led? If what is said here is true then you would be able to see an approximately uniform 15% increase (I got closer to 12), and that means that the OSTS TN31 would be able to put out up to 316250cd and at a low 256000cd. I don't think that Saabluster would go for that, but being able to have a 300kcd+ hand held light . The construction is slightly different as well, I have heard discussion of possibly flipping the die upside down and that eliminated the tracks as well as dropping to 2 leads to the active area. This seems like it would make the new led easier to de-dome, which I am interested in. The anode seems to have a slightly different construction, and there doesn't seem to be any topside pads for connecting to power source (though after looking at the diagram at the bottom of the data sheet it does seem to be separated down the middle for one side positive and the other negative).

  23. #53
    Flashaholic* uk_caver's Avatar
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    Default Re: Cree XM-L2 Finally announced

    It does seem odd, if the light used a reflector, that a more centre-biased LED would give greater lux.

    Assuming accurate measurements and not some mundane thing like better positioning with the XP-G2, it would make me wonder if it was a larger dome refracting the 'somewhat sideways' light less and making the effective die size smaller, rather than being some function of a slightly different nominal viewing angle.

  24. #54
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    Default Re: Cree XM-L2 Finally announced

    Quote Originally Posted by uk_caver View Post
    Scaling/overlaying the spatial distribution curves on the same scale shows what looks like a small difference
    I did the same thing today with the XM-L and XM-L2 sheets, appears to be a very slight narrowing on the XM-L2. Or it could just be that the graphs aren't that accurate.

    Looks like all physical dimensions are exactly the same, I found an updated XM-L sheet that showed it has the same dome radius as the XM-L2.

  25. #55
    Unenlightened M79's Avatar
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    Popcorn Re: Cree XM-L2 Finally announced

    Hi,

    I`ve spotted xm-l2 emitters on digikey; min. order quantity is 250 and at the moment there are only t5 (4.62$/piece@250 reels) and t6 (whooping 7.16$/piece@250 reels) cool white bins available (in stock!).



    cheers


    PS There are also prices given for many other bins (incl warm white) in 1000 or 1 piece quantities.

    full list:
    http://www.digikey.com/scripts/dksea...=0&ptm=0&fid=0
    Last edited by M79; 12-16-2012 at 06:13 PM.

  26. #56

    Default Re: Cree XM-L2 Finally announced

    There are U2s available in single pieces, too. CCT 6650 K, though.

  27. #57

    Default Re: Cree XM-L2 Finally announced

    They're available at mouser too.
    Last edited by hellokitty[hk]; 12-16-2012 at 10:32 PM.

  28. #58
    Unenlightened M79's Avatar
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    Default Re: Cree XM-L2 Finally announced

    @moozooh: only t5 and t6 cool white are immediately available at digikey
    @hellokitty: brilliant, my favourite 2700k`s in stock. Guys please note: xm-l2 2700k (ht2e8) 1 piece, 4.82 euro`s and xm-l 2700k (ht2e8) 1 piece - 7.0. If it is not only introduction price, then we indeed have some nice price drop here

  29. #59
    Flashaholic* psychbeat's Avatar
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    Default Cree XM-L2 Finally announced

    Quote Originally Posted by moozooh View Post
    There are U2s available in single pieces, too. CCT 6650 K, though.
    Get warmer with the top dropped
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  30. #60
    Flashaholic* monkeyboy's Avatar
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    Default Re: Cree XM-L2 Finally announced

    5700k u2 bins are on order at mouser and available to preorder. E2 grouping.

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