The NAO headlamp features "reactive" lighting to offer varied brightness and beam patterns that can spotlight physical features 300 or more feet away or provide soft illumination to read a map in your tent.

OK, most headlamps are adjustable these days, but with the NAO, the adjustments happen automatically. No fiddling with buttons and knobs—just point the light and it changes the setting for you. A light sensor (similar to those used in cameras) detects ambient light and communicates the information to two LEDs. It's an impressive range of lighting: The output grows from seven lumens (the lighting equivalent of a candlelit dinner) to 355 lumens; the beam goes wide for closer objects and concentrates to a spot for long distance.

Petzl's new NAO headlamp has guided my post-work, after-dark trail runs for the past month. The adjustments happen so fast and so smoothly that it's hard to tell it's working. But what is perfectly clear is that I see what I'm looking at—whether it's rocks at my feet or the next turn down the path. When I'm looking through the contents of my pocket or eyeing a dark shape in the middle of a pond, the NAO provides enough of the right light to see what I'm looking at.

The unique rigging is comfortable and lightweight, built for trail running and other endurance activities. A lithium-ion battery is recharged via a USB port, but you can use regular batteries for long backcountry trips. Plus, Petzl will provide free software for download that allows you to customize light reaction times and settings. Available July 2012. $175; petzl.com  —Olivia Dwyer