Actually shows some of the light patterns on the ground,,
Bicycle Light Comparison Guide - Modern Bike
In the woods, on the trails, at the speeds a sane person would ride at in most trail conditions, on a solo ride I found that 250-550 lumens is plenty on the handle bars for me, with a cateye at about 50 lumens on my helmet. But on group rides of three or more I'd want to have 550 to 750 lumens on the bars.
On all rides mount your most powerful light on the handle bar, your second most powerful on your helmet and carry a third backup light in your pack for that bad crash where you could loose one and damage the other..
Finding the one that popped off your handle bar with the helmet light broken, In the dark,, fun fun
My Primary light:
http://www.modernbike.com/niterider-...headlight-2015