one thing the fenix (in particular) uses one of the best curcuit methods around, actual current control, not PWM, or other methods that can waste a lot of power. and according to all the specs and charts and the myriad of data on all this stuff, it must be a very smart design, because the data shows its not wasting power left and right.
5MM leds provide a FLOOD pattern more often that not, and a SINGLE led in the bottom of a tight spot reflector will always LOOK much brighter.
which one can light up a whole room the same way when you hit the ceiling, is the total "lumens" output.
the fenix is 50% spot with unfocused spill running about, its certannly not a flood lamp.
spread 3sq inches of light out to 9 square feet, and there is less of it to go around, the math on that, something like 1296sq inches.
it looks like the corona curcuit design sucks, they dont need that kind of heat sinc for the little leds, so that sinc in there is probably connected to parts of the low efficiency curcuit, to keep the heat off of it. anything the spews out heat, is wasting the energy in heat not light.
There ARE reflectors for 5mm led, when added to a 5mm led, the light that escapes the edges (which still gets listed as lumens when analising the part itself) can instead be reflected foreward.
i have used the 5mm led Reflectors, and they can put out 40% more light foreward with them.
so some of this design itself , looses the light falling out the sides of the led, which can be quite a bit of the light.
5mm leds do not put out the same light they did 300 hours of use later, they are only decent output for 3000-5000 hours of use at SPEC, when driven over spec, they reduce in output very rapidly, and all "WHITE" leds using phosphors, the phosphors eventually fade, every "NEW" light looks great compared to yesterdays light, because phospors dont live forever. therfore, the most valuable most used "white" led flashlight is always going to dim over time, and the new ones will always wow you , even if they too will eventually fade in time (when used).
then if you say Love the fenix, there are people who have taken the HEAD off the fenix, and Stuffed it on a headband , and have a headlight, with a tiny bit of enginuity a headband, and something to screw a flashlight head into, any flashlights head can potentially become a headlight
OR, take the night eyes headband that holds a minimag, on the side of your head, and stuff your fenix in there instead. 5$ mod to give dual use to any flashlight.
anyways there is some thought about it.
here is a link
http://www.candlepowerforums.com/vb/showthread.php?t=171271
i have done similar things before with good results, a head is just a head , screw it off, and it can be connected to your head
