On Sun, 10 Dec 2017 20:35:37 +0100, Sepp Ruf
wrote:
Tim McNamara wrote:

There are only two choices with a reversed crescent cutoff: Either
aim it low enough that it does not glare directly opposing traffic,
or aim it high enough to keep the 90 and 270 degree fields of vision
for fast curves.

Reversed crescent meaning the arc is oriented with the high point on
top or below?

single high point on top.

Ah. Well, that's the easiest way to do it given a round lens and
concave reflector. Having the ends of the crescent be higher, or the
top of the beam be flat, would do a better job of illuminating the
terrain into which one is turning without blinding those coming towards
you. That takes some computer analysis and optical manufacturing nous
to be able to do. I don't know if Oculus manufactures their own stuff
or assembles off-the-shelf components into their product. The latter is
quite common but not universal.