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Thread: XM-L for the sake of XM-L?

  1. #1
    Flashaholic Blitzwing's Avatar
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    Default XM-L for the sake of XM-L?

    Just looking around it seems the XM-L is being put into a lot of smaller lights that don't have the heatsinking ability to handle the emitter when driven hard. 1.5 and 1.75A drivers and so on. Small pocket lights with small reflectors.

    Why not just run and XP-G and run it at a similar current? I know folks like to see "500 lumens" in ads for small pocket lights and no doubt that sucks a lot of folks in. As does the "XM-L" in the title. But most of us know that the XM-L isn't anywhere near its best in a small reflector or when run soft. There are also the heat issues in the very small lights.

    From my own experience in P60 lights, the XM-L only really comes into its own when run near 3A, giving decent throw and tons of spill. And then you have some pretty rapid heat buildup if used constantly. The XP-G is also no slouch in the same format, either mind you and you get none of that heat.

    So - is the XM-L being used for the sake of it in smaller lights, or what? Will the XP-G G2 get similar market exposure or will the XM-L continue to overshadow the smaller emitters?

    Just a thought.

  2. #2
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    Default Re: XM-L for the sake of XM-L?

    The XM-L has the highest lumens per Watt of any currently available emitter, though the XP-G2 is going to give the XM-L a run for the money. Taking an XR-E or Luxeon out of a light and replacing it with an XM-L will give you a higher volume of light with a large hot spot compared to the older emitters, though the intensity of the hot spot will be less. You don't necessarily need to run the emitter at three or more Watts to benefit from the higher efficiency. Leaving the driver and just changing the emitter will almost double the output of most older lights.

  3. #3

    Default Re: XM-L for the sake of XM-L?

    Quote Originally Posted by Blitzwing View Post
    I know folks like to see "500 lumens" in ads for small pocket lights and no doubt that sucks a lot of folks in. As does the "XM-L" in the title.
    Yep, XM-L has become almost a synonim for brute power and it surely does make flashlights sell, especially in a budget light market. But, as you say, other things must be counted in when someone's building a flashlight around XM-L (size of the reflector and heatsinking properties of flashlight itself, available current etc.) or everything doesn't make much sense. If someone's happy with a 500lm non-thrower pocket rocket that heats up in the matter of minutes, that's OK. BTW, my night-time EDC is Solarforce L2 with a (properly heatsinked) single-mode LC-XML drop-in

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  4. #4

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    I like floody beam provided by the large emitter in small head - don't want pure flood though, just a big hotspot and smooth transition to spill. I run my lights mostly in the single digit lumen range so heat is rarely a problem. Using single cell Eneloops and 14500s, I don't spend much time at max.

  5. #5

    Default Re: XM-L for the sake of XM-L?

    Why not just run and XP-G and run it at a similar current?
    That doesn't help at all with the heat issues that you're talking about.

    I like the flood. I would much rather have an XM-L especially in a small form factor light because for a small light, I'd probably use it for closer things.

  6. #6
    Flashaholic* madecov's Avatar
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    Default Re: XM-L for the sake of XM-L?

    I like the XML in my lights maore than the XPG. I find even though it is a floodier beam it throws just as well and is more suited to every day tasks.
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    *Flashaholic* fyrstormer's Avatar
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    Default Re: XM-L for the sake of XM-L?

    There really is no reason to use the XM-L in a small light except for the reasons the threadstarter stated. Big numbers, high efficiency, and most people put more of a premium on the WOW factor than on a specific beam pattern.

    I just bought some RRT-0's on clearance. I opted for the XP-G version because it just plain works better in that small of a light. I have a TC-R1 with an XM-L, and while it does produce an impressive amount of light, even pointing it at a wall a few feet away I can see the RRT-0 XP-G has a sharper beam. Maybe the XP-G2 will sway things back in the direction of a beam with a proper hotspot instead of a wall of light.

    That being said, if a wall of light is what you want, a hard-driven XM-L (or better yet, an SST-50) works very well. I don't know if it works as well as a Tri-XPG with a 3-up TIR optic, but it does a fine job.

  8. #8
    Flashaholic* Lou Minescence's Avatar
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    Default

    I like the XML for high and low lumens.
    The larger hot spot f the XML on low is more useful to me than the XPG. I also like the larger hot spot of the XML in my neutral and warm lights over my XPG neutral and warm lights.

  9. #9
    *Flashaholic* kramer5150's Avatar
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    Default Re: XM-L for the sake of XM-L?

    Peter beat me to it... Lumens per watt efficiency I think is the main reason. I think a lot of folks would prefer a smoother flood-beam in a small EDC, the bigger XML will flood more (generally speaking). I also think (generally) the XML color tint is more stable at lower drive currents. My 1A tint XMLs fade towards the yellow spectrum at lower currents, while my XPGs almost always appear more green.
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  10. #10
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    Default Re: XM-L for the sake of XM-L?

    Blitzwings thoughts are justified. I think it to a certain level can be that the title XM-L sells. Very small lights have not adequate heatsinking for high outputs, and according to what recently has been said at this forum XP-G is more efficient at low outputs. But for the sake of a floody beam XM-L is great.
    Last edited by Swedpat; 08-10-2012 at 12:39 AM.

  11. #11
    Flashaholic* skyfire's Avatar
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    Default Re: XM-L for the sake of XM-L?

    i agree with blitzwing. i dont see a point in having a XM-L in a small light. none of the lights in my stable use a XM-L, but thats also because i dont have any lights larger than a 1x18650 form, and i have a huge preference for high CRI. i still prefer the tint and CRI of the high CRI XP-G over a XM-L 3000k.

    hellokitty is correct in that a small to medium size light pushing an XP-G at 1.5 amps can still generates plenty of heat.
    I for one, dont like any lights that can get too hot for its own good.

    an XP-G can be just as floody as a XM-L. beam pattern is all in the optics design. but a XM-L cannot have the throw of a XP-G when trying to be as compact as possible. a XP-G can be even more compact if designed for flood.

  12. #12
    Flashaholic Blitzwing's Avatar
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    Default Re: XM-L for the sake of XM-L?

    Interesting and enlightening comments.

    I too thought about the optics options with the XP-G to give more flood.

    I quite like my three mode Solarforce XP-G dropins, even though they are conservatively driven. To my eye, they throw as well as my Ultrafire three mode XM-L dropin which is one of the harder driven P60's out there according to reviews.

    I have a Roche F12 coming soon, with the XM-L so I'll be interested to see what that's like. (the Intl-outdoors version)

  13. #13

    Default Re: XM-L for the sake of XM-L?

    The problem with small lights isn't XM-L, it's that they're pushed too hard. XP-G isn't more efficient than XM-L at lower currents—XP-G2 is, and it's not yet used in mass-produced lights. XP-G at 1.5 A will generate more heat than XM-L at 1.5 A exactly because it's less efficient; i.e. more power will be converted into heat.

  14. #14
    *Flashaholic* Gunner12's Avatar
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    Default Re: XM-L for the sake of XM-L?

    I'll be cool to have a small temperature sensitive resistor attached to the heatsink near the emitter. as the emitter heats up, the resistor increases resistance so the current to the LED is controlled. This would add a few extra parts to the LED though and increase cost.

    As for XM-Ls in small lights, I like the efficiency they provide and that they allow very high output. IMO, as long as the user understand that he/she can use the light on max for too long, then the light should be fine.

    I think the XM-L is being placed into smaller lights both for the higher max output, the ability to market an XM-L light, and for the higher efficiency at lower currents.

  15. #15
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    Default Re: XM-L for the sake of XM-L?

    I like both for the reasons already stated. I like the XM-L and the "wall of light" effect for closeup work at low lumens, EDC and around the campsite. When I feel the need for a little more throw, tighter defined beam then I grab an XPG. They are both great IMO and I'm glad that I have each.

    The pocket rocket thing does seem a little excessive sometimes, but hey what ever makes you happy.

    These discussions are good for us non flashaholics.
    Last edited by bushmattster; 08-10-2012 at 10:22 AM.

  16. #16
    Flashaholic OneBigDay's Avatar
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    Default Re: XM-L for the sake of XM-L?

    Very interesting question and responses. Here is my $.02

    I think an XM-L is perfect in a small (~20mm) reflector. For example the new Eagletac D25 series. I bought a few of these in both XM-L and XP-G , and I prefer the XM-L not because of the output or marketing hype or whatever. I prefer it because the large emitter surface with a small reflector produces a great smooth floodlight with a huge hotspot. For EDC I think an XM-L in a 1xAA form factor is awesome.

    Bring on the flood!

    I never saw this with the SST-50 which in my opinion always had better more consistent tints than the XM-L. The SST-50 wasn't as efficient and was more expensive than the XM-L. For these reasons I think the commodity factor of the XM-L is higher and therefore it appears manufacturers are experimenting more with this LED in different formats and form factors. Maybe others have a different take on this but otherwise I can't explain why the SST-50 never took off in smaller form factors but the XM-L is definitely creeping into that space.

  17. #17

    Default Re: XM-L for the sake of XM-L?

    Maybe manufacturers will catch on that many want wider floody beams. Any of these LED's are capable of that with the right optics. XM-L just makes it impossible to get the tighter beam without a larger reflector. For most tasks I prefer a wider beam and spill as well.

  18. #18
    Flashaholic Blitzwing's Avatar
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    Default Re: XM-L for the sake of XM-L?

    I guess I'm biased in some ways as I prefer throw - horses for course of course.

  19. #19
    *Flashaholic* easilyled's Avatar
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    Default Re: XM-L for the sake of XM-L?

    So to summarise:-

    XM-L not for the sake of XM-L but for more efficiency and a floodier beam distribution than an XP-G

    XP-G for less efficiency and less output at the same drive level (than XM-L) but a beam distribution geared more for throw (smaller more intense hotspot)

    XP-G2 for similar efficiency to an XM-L but much more throw, significantly more than even an XP-G
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  20. #20

    Default Re: XM-L for the sake of XM-L?

    I just wanted to add my own comments to the discussion. After reading the thread I surmised that most people who prefer a thrower will agree that the trend of manufacturers adopting the XM-L is due to the desire to produce a floody light in a pocket size format. I think it is simply to keep up with trends in hardware where a newer more efficient emitter is available for a reasonable cost that gives an ample increase in output, with a significant gain in runtime. Sure you can drive an XP-G near it's limits at 1.5 amps and get a nice beam that is certainly bright enough for most of us but pushing the LED as hard as you can....or you could drive an XM-L at 1.5 amps, get more light output and not have as much heat plus still have another 1.5 amps of current to go before exceeding it's recommended operating range, thus extending the life of the LED itself.

  21. #21
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    Default Re: XM-L for the sake of XM-L?

    I think the xp-g2 is going to be sweet. Lots of light from a not too big source No problems to make it both floody and throwy, it's depending on optics. A step in the right direction for a "jack of all trades" led.
    For really wide flood with huge diffused "hotspot", i like the flood tir optics. The old malkoff m60wlf and univex aaa's are some of my most used flood lights around home The triple xp-g p60's also got a great floody beam. Havent seen any light with a xm-l and a flood tir optic yet, and a xm-l in a small reflector (mini-x), dont come close in floodyness to any of the above.

  22. #22

    Default Re: XM-L for the sake of XM-L?

    Color separation is a real problem with the XM-L as discussed in this thread:

    http://www.candlepowerforums.com/vb/showthread.php?309724-XM-L-Color-Separation

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