Originally Posted by slvoid
Ok, I realized that my light has a more efficient reflector and apparently, light & motion uses custom halogen bulbs that get 30 lumens/watt. Which means that the 16 watt beam that I normally run gets about 480 lumens, and the 11 watt beam gets 330 lumens, which explains why it gets almost as much light as a HID. And on both beams, I'm running around 800 lumens.
I'm pretty sure that there is nothing special about the L&M bulb, what they are doing is "over-volting," running a stock 6V halogen bulb at 7.2V.
There is an interesting article about watts vs. lumens here:
http://nordicgroup.us/s78/wattslumens.html
For me the most eye-popping thing is that a halogen bulb over-volted by 20%, like the L&M, can give more lumens per watt than a HID. The tradeoff is that bulb life suffers.
Here's another good article:
http://www.myra-simon.com/bike/lights.html