Originally Posted by
Mark Kelly
This.
What really matters is not so much the total lumens but the combination of this with spectral distribution. A 350 lumen LED gives a lot of light but much of it is useless - a white LED is basically a blue LED with a yellow phosphor in front, so you get two distinct peaks. This gives a dazzling light when you are looking at the source, but it can give very poor surface illumination if the surface doesn't happen to respond to either blue or yellow light.
An equivalent incandescent or HID lamp will spread those lumens over the entire spectrum so no matter what the surface it will be well illuminated.
The tradeoffs are luminous efficacy and cost - a 350 lumen incandescent will chew around 15 watts, an HID will chew around 5 watts but cost an arm and a leg, an LED will chew as little as 3 watts but give crap illumination as explained.
I went from a Light and Motion traditional light with a separate battery rated @ an alleged 650 lumens to this new 500 lumen light by Serfas. I did the Pcad Shed TestŪ. That's where I stand by my garage and shine the light onto my shed, 150 feet away to compare the light pattern and brightness. The Serfas light seemed identical to the Light and Motion light on its highest setting, despite being rated 150 lumens lower. The Serfas light is also a self contained and very compact flashlight design with an internal battery. Superior in just about every respect, including the fact that a spare battery (which you can easily carry in your pocket) weighs about as much as 3 AA batteries and is relatively tiny. The Serfas light goes on top of my helmet which really does provide a superior lighting experience to having it on your handlebars for a number of reasons. Plus if you have a puncture or other issue, you have light wherever you turn your head. Sure it looks dopey, but who's going to see you in the dark @ 5AM?