john

Headlamps are great for nighttime mountain biking.. But used in lightening
sky or with park / street lamps in background, it works as great stealth
technology.

This is old technology, it was use very successfully to attack u-boats
during ww2. By putting bright lights down the wings, etc, the aircraft was
no longer a black speck, but would fully dissappear into the background.

Please consider this before you ride on the road with your super bright
headlamp. your head and upper body will dissappear against a dusk or dawn
sky, or since the light is up so high, you may appear as a streetlamp. This
winter especially (maybe due to more cyclists going to headlamps? ) I have
missed seeing a number of headlamped cyclists and have almost hit them,
mostly on the waterfront. You are probably better off using two lights at a
normal expected height...
Just a observation/ FYI, be safe !