There are a few things to consider when purchasing a headlamp. The most important factor is the lumens, which measures the amount of light emitted by the headlamp. The higher the lumens, the brighter the light. Another important factor to consider is the beam distance. This is how far ahead of you the headlamp will illuminated. A headlamp with a long beam distance is ideal for night time activities such as camping or hiking. Finally, you'll want to consider the weight of the headlamp. If you'll be wearing it for long periods of time, you'll want a lighter weight model.
Some of the highest quality headlamps on the market include models from Black Diamond and Petzl. Black Diamond's Storm 400 Headlamp boasts 400 lumens and has a beam distance of 70 meters. It also weighs just 160 grams, making it one of the lightest weight options available. The Petzl NAO+ Rechargeable Headlamp also has an impressive output of 575 lumens and can run for up to 20 hours on its rechargeable battery pack. It has a slightly shorter beam distance than the Black Diamond model at 60 meters but is still more than adequate for most needs.