Interesting. I looked at the size of that L5. I don't know what modded LED you have in it, but there is no LED out that will produce an actual 1000 lumen OTF output on ONE 18650. The XM-L is the brightest LED module out there right now. TWO of them could put that out, but not on one 18650.
My Jetbeam BC400 puts out over 800 actual out the front lumens, but it uses two 18650s.
However, many LED flashlights are rated at what they theoretically put out at the actual emitter, in the first second. Many companies take advantage of people by posting #'s they can't possibly achieve.
Yup, that's true, mfr's often post theoretical or at-the-emitter lumens. And you might be right about my L5, if it was a single emitter. But...
It's a tri-MC-E =) Using multiple emitters lets you take advantage of the higher efficiencies at lower current, stacked then across three emitters.
I do have another 1x18650 XM-L light, and it does produce almost 1000lumens OTF, not quite but almost =) It's a nice thrower.