Echo63 said:
rdh226 said:
Surefire U2
is a GREAT multi-level (6) LED, not as bright on high as the L4, but much more versatile.
your U2 must have flat batteries then
my U2 craps all over my L4
it is about equal when you turn the U2 down to about level 4
the L4 is a great light, it was my second surefire, i still have it and still use it regularly
although my EDC light is either my U2 or strion, simply because the strion is rechargeable and the U2 is so versatile, long running and dim or screaming bright - it does both and lives on Pila's so it is cheap to run too
OK, let me qualify that...not batteries (I swapped the pairs). The U2 high (stage 6)
definitely has a brighter center torus ("doughnut") than the L4 (to the crudely-
measured tune of 130fc to 100fc), but offcenter the L4 has a much broader swath
of light than the U2 (60fc [L4 to the U2's] 20fc), and it's a wider dispersion too.
My perception is that the L4 is much better at lighting up an area (room, hallway,
cave, etc.) than the U2 with it's much more concentrated throwy (center-weighted)
beam. The (my) perception is the L4 puts out more light overall, even though the
U2 is the no-contest brightest-single-spot winner.
This did make me look more closely at my earlier attempts to quantitatively mea-
sure the lights' TOTAL output using my Simpson 408 Illumination level meter
and its diffusion filter. Looking more closely at the diffusion filter I realized that
it very strongly favors center beam, which ironically caused the U2 to score very
low. My measurements ended up comparing L4 center-weighted beam to the U2's
donut hole! NOT what I intended to measure at all! Fascinating...
-RDH