5W LS lumen output

The 1W LS is rated at 25 lumens max, the 3W at 80 lumens max and the 5W at 120 lumens max. So why are all the 5W Surefire lights at 65 lumens? I realize that not all of the light produced by the LED actually comes out of the flashlight, but only 54 percent? Some 1W lights almost reach the 25 lumens. Are there any 5W LS lights that come close to the 120 lumens?

It is fairly known here that SF list their light spec conservatively. That said, it is highly possible that the 65 lumens is the promised light output and you can get more in actual usage. ALso, SF's light is underdriven by about 666 mA so that count to a drop of ~20 lumens or so.

just my thought

first of all, those ratings aren't true.
they're not "maximums", they're averages.
an x binned 5watter can put out over 200lumens when driven at specs.

surefire doesn't drive the 5watters are full throttle. they are underdriven, though i'm what they are driven at.
assuming that their luxeons are 120lumen-bins (they could be more or less), then assume they are driving them so that they put out 100lumens.
then figure in optical efficiencies and you've got a lot less.

also figure that surefire rates their products very conservatively. if they say it puts out 65lumens, then it will likely put out at least 65lumens, meaning likely more.

by the way, is it 65 lumens? i thought some were rated at 85? /ubbthreads/images/graemlins/thinking.gif

Also remember that the lumen ratings given by lumileds are with a junction tempreture of 25 degrees C, something that just doesnt happen in most flashlights.

It is likely that Lumiled measured the LED bare, i.e. without any optics/reflector?

[ QUOTE ]
Alan Hsu said:
It is likely that Lumiled measured the LED bare, i.e. without any optics/reflector?

[/ QUOTE ]
Testing is done on the emitter only. Here is the official Lumileds word on optical testing. Note that all measurements are made in a single 20 msec pulse so heating in negligible.
AB08 Optical testing

[ QUOTE ]
Alan Hsu said:
It is likely that Lumiled measured the LED bare, i.e. without any optics/reflector?

[/ QUOTE ]
Sure. Otherwise it wouldn't make any sense.

Have a look at this posting/thread:
http://www.candlepowerforums.com/ubbthreads/showthreaded.php?Cat=&Board=UBB31&Number=317399&page=&view=&sb=5&o=&vc=1