Question on Cree XM-L2 U2 tint LED

Timothybil

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I own a Nitecore EA41 (2014). In looking at the specifications, Nitecore says they use a Cree XM-L2 U2 LED. When I look at the datasheet for the XM-L2, I find the U2 in two separate categories: Cool White 5k-8k, and 70+ CRI 3.7K-5K. This is telling me that the U2 hovers around 5000 K, with individuals falling into either category. Is this correct, or is there some other reason?
 

Chicken Drumstick

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It's probably worth reading up on this.

U2 is the brightness bin. CREE bins the leads into different groups based on their output range. They then also have a tint, that many places don't tell you. Some tints are available across multi brightness bins, while others aren't.
 

yellow

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As has been typed:
Brighness bin has no value at all to light color tint ...

The Individual tint ranges are much tighter than the 3000 k you found
(must be some "general" tint overviews ...)
 
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WalkIntoTheLight

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As has been typed:
Brighness bin has no value at all to light color tint ...

The Individual tint ranges are much tighter than the 3000 k you found
(must be some "general" tint overviews ...)

Yeah, they probably just order whatever's cheapest, without regard to a specific tint. You play the tint lottery, after that.
 

Timothybil

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It's probably worth reading up on this.

U2 is the brightness bin. CREE bins the leads into different groups based on their output range. They then also have a tint, that many places don't tell you. Some tints are available across multi brightness bins, while others aren't.
That makes sense. The drop in I was looking at offers the following LED options:

  • XM-L2 U3 1A: Cool white (~6500K). Approximately 1125 LED lumens. OP (orange peel) or SMO (smooth) reflectors.
  • XM-L2 U2 3C: Neutral White (~5000K). Approximately 1075 LED Lumens. OP (Orange Peel) reflector.
  • XM-L2 T4 7B4: Warm white (~3000K). Approximately 850 LED lumens. 80+ CRI for more accurate color rendition. OP (Orange Peel) reflector.
  • Nichia 219B: Neutral White (~4500K). Approximately 500 LED lumens. 92+ CRI for superb color rendition. OP (Orange Peel) reflector.
So the U3, U2, and T4 are brightness bins, and within them the 1A, 3C, and 7B4 define tints, am I correct? And several different brightness bins could have a 1A tint, as well. That is starting to make sense, but now I am going to go crazy trying to find out which tint my XM-Ls are, since they are never mentioned in the specs.

Thanks for the info. It helps alot.
 

Chicken Drumstick

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Yep that's it.

As a rule the nicer/better tints aren't the highest output ones. But the difference in output is small enough that you really can't tell by eye. But tint you can tell all the time. I'd personally always buy on tint first, output second.
 

Cyrax

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I wonder why srt7 a better range and brighter than pd35, anything the later is a u2, whereas former is t6
 

WalkIntoTheLight

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That makes sense. The drop in I was looking at offers the following LED options:

  • XM-L2 U3 1A: Cool white (~6500K). Approximately 1125 LED lumens. OP (orange peel) or SMO (smooth) reflectors.
  • XM-L2 U2 3C: Neutral White (~5000K). Approximately 1075 LED Lumens. OP (Orange Peel) reflector.
  • XM-L2 T4 7B4: Warm white (~3000K). Approximately 850 LED lumens. 80+ CRI for more accurate color rendition. OP (Orange Peel) reflector.
  • Nichia 219B: Neutral White (~4500K). Approximately 500 LED lumens. 92+ CRI for superb color rendition. OP (Orange Peel) reflector.
So the U3, U2, and T4 are brightness bins, and within them the 1A, 3C, and 7B4 define tints, am I correct? And several different brightness bins could have a 1A tint, as well. That is starting to make sense, but now I am going to go crazy trying to find out which tint my XM-Ls are, since they are never mentioned in the specs.

Thanks for the info. It helps alot.

Go for the Nicha 219. I like the 219A, but the 219B is supposed to be good too. It will give you the best tint, though isn't high output.

For a good compromise between tint and output, go with a XM-L2 neutral white.

I haven't tried a 7B tint, but it sounds a bit warm for even my tastes. Might be nice as a "mood light", though.
 
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