Originally Posted by
Burton
A while back I posted some specifics comparing the coverage and power requirements of a 15 degree beam
to a 45 degree beam. The long and short of it was that it would take about 9 - 300 lumen lights with a 15 degree spread to illuminate the same area with the same intensity as one 2,600 lumen light with a 45 degree spread. I think we're so used to narrow beams that the power requirements for anything else has been forgotten. LEDs are being marketed to the automotive industry, but an automobile headlight typically has a 90 degree spread and as a consequence, the power requirements for LED headlights aren't all that different from the halogen units they're replacing. But they do provide more light.
Actually, 2,600 lumens spread over a much larger area isn't all that bright. But personally I do find lighting a larger area provides a greater measure of safety. I wouldn't want to drive a car with only 15 degree beams for much the same reason.
That is correct, a lot of bicycle lights have a narrow cone of light, but in that process they light up tree tops that don't need to be lit up for us to ride with, which is what cars do, their lights are aimed low and wide instead of high and narrow like most bike lights, which is why the Phillips Saferide looks brighter and wider than most of the lights compared at MTBR backyard beam shootout even though it "only" has 400 lumens is because they aimed the beam similar to a car headlight. Other bike light companies need to focus on getting the beam aimed where we need it-on the road, and not at showing off lumen numbers, I could care less if I can see an owl sitting on top of a tree!