thesurefire said:
Most 5 watt flashlights that are driven at spec using even an ok luxV should put out 100+ lumens. The good ones should put out 150+ lumens.
Quite a few people, and even alot of flashlight manufacturers don't understand Lumens all that well.
Just because an LED puts out 100 lumens on the datasheet, it does not mean you get that in a flashlight.
First you have to realize that the 100 lumens on the datasheet is done with the die at 25C. It is much lower in a flashlight, as the die heats up quite considerably. You can get a 30% loss in lumens with no problem here.
Next, there is loss due to the reflector surface, which can amount to 30% or more, or less, if exotic reflector coatings are used.
Then you have loss due to the front lens, which can be as high as 12% or as low as 1%, depending on how exotic the glass and AR coatings are.
Most likely, the lumen increase is due to LED efficiencies, which have gone up alot. Though, don't take this as fact.
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