XPL vs XPL-HI

greatscoot

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Dec 14, 2011
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I'd like to know what the difference is in these two LED's. Primarily I'm interested in tint and throw. Currently I have an M91 in both 4000K and 5000K XPL and the 5000K looks pretty white to me, but as much as I like to 4000K, in tends to be a little yellow for my tastes. I know that a lot of this is subjective, but I'm trying to figure out which LED I'd like to spec for a light I'm looking at.

Any thought would be helpful.

Thanks.
 

DIWdiver

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Jan 27, 2010
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The XP-L has a dome on it, the HI doesn't.

The dome increases total light output in lumens (explanation on request), but it also magnifies the apparent size of the die. This causes a reduction in the apparent surface brightness of the die.

Surface brightness, not total lumen output, determines how much throw you can get from an emitter. I can explain this too, but others can do it better. So applications that need lots of throw, like throwy flashlights, narrow spotlights, and projectors, benefit from the lack of dome on the HI. Applications that benefit from higher lumens, like area illumination, are better served by the XP-L.

Not too sure about this, but I think the dome also helps reduce color fringing or haloing, where the outer edges of the beam have undesirable color changes.
 
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