Bests & Worsts Reviews from Amazon

I bought this headlamp for its price/performance ratio and the glowing reviews. It has some impressive specs, and features, but in the end I was dissatisfied with the purchase. I have more LED headlamps and flashlights than one probably should own. Those devices set my expectations. Things I really like about this unit is the infinite dimming achieved by pressing and holding the power button, the proximity mode (even though it underperforms any other proximity headlamp I've come across, it is nonetheless useful) and the small light form factor. I was also impressed with the helpfulness and honesty of the Black Diamond customer service folks, who were very open about the fact that my main issue with the light was a side effect of the high power design and not likely to be eliminated by any action on their part. I also like the battery meter (3 levels only, but when red is a good thing to know). My first observation is the common view people have that doubling the lumens doubles the apparent light. It simply doesn't, the human perception of brightness, like sound, is not linear. I don't know the exact factor but you may have to quadruple the lumens to double the perceived brightness (this is simple physiology). So, going from say 50 lumens to 60 lumens may not be noticeable by most people while the increased battery consumption will be very noticeable. Hence, I was not surprised that the Black Diamond spot light was marginally brighter than an old Petzl both with new batteries even though the Petzl has far lower lumens. My second observation is the spot light is really tuned for distance with no adjustability. That's the target audience, if you want to use it more in a flood configuration this light is probably not for you. Adjustability would be nice for better versatility. However, you can cast a lot of light on a small up close area for detailed viewing and drop the intensity which makes it useful up close. This brings me to my primary issue. My big issue is the light has a bright white spotlight, but in the middle of that spotlight it emits a small area of bright yellow. This yellow region does not disappear if you lower the intensity. Because the light is very non-uniform in the focal area it completely distorts detailed viewing at that spot. As such, if you were trying to scan a surface for some kind of detail, and you are like me, this will drive you crazy. As mentioned earlier, I don't have any such artifact in any other LED light I own. Reaching out to the Black DIamond people, it seems that most people don't mind the distortion. This is the main reason I rank the light 2 stars, but looking at other reviews it seems it isn't a concern for pretty much anyone. Finally, I have a small gripe with the battery compartment. It's not intuitive how to open it and it is not spelled out very well. It's unnerving to pry the plastic and pull at the body as it finally unclips because it feels like it wasn't meant to be torn apart like that, but once I got it, it was okay. However, I can easily see someone prying it open at the wrong end and snapping the little plastic tabs that hold the case together which would render the light useless. In summary, really like the company, like several aspects of the light but would not recommend it for my use case. For trails, long range non-detailed lighting I would recommend it.