Thank for the input! I wasn't actually planning on doing a tutorial - was hoping more on starting some kind of discussion on what cyclists would like to see in a headlight. Can't think of a better place than a forum to do that!

The beam spread I'm currently using is a personal choice and not necessarily a general recommendation. On several ocassions on my commute home late at night I've had kittykats with racing stripes (skunks) amble across the path - resulting in near misses for both of us. The broader beam picks them out easily and gives me lots of warning. Lots of worms in the grass late at night and I guess thats what they're after.

There is some scatter from the light, but the majority of the output is constrained to 15 degrees which, when aimed downwards - puts almost all the light on the ground. It has the added advantage of being brighter over a wider angle of view than a plain 15 degree light.

I gess we could start a discussion on how to aim lights but we'd have to start by deciding what the optimal beam pattern is - off-road and on-road. I'm thinking different people may have different preferences. But I certainly have enough lights here if anyone wants to make suggestions on optimal combinations.

Based on your earlier comment I'm thinking that a combination of two eliptical beams with one or two regular spots might be more to your liking. Lets see where the post goes with the rest of the forum.