As a result of years of recommending lights on /r/flashlight, people have been asking me to write blog posts along the lines of "Best Flashlight for 20XX." Problem is I've never seen a good write up in that style. They are almost always horribly written affiliate content mill pieces. The fundamental purpose of my site is to show that there is a better way of recommending products, and I feel there has to be a better way. So this is my first attempt at breaking that mold: here's what to avoid buying.

Headlamps are possibly the most useful form of illumination technology around. They always put light exactly where you need some. How often have you set a flashlight down, only to find you still needed it a minute later? A headlamp is always with you. And most importantly, they leave both of your hands free. But there are hundreds of headlamps out there. How do you choose the right one for you?

First, think about what the headlamp is used for. I've found that there are two primary use cases:

• Working with your hands in the dark. Stuff like fixing things, cooking food, first aid.
• Moving around in the dark. Hikers, runners, bicyclists.

Your headlamp can be optimized for either of these. Working generally requires a broad, even beam pattern like a flood light. Generically this is described as "floody." Moving requires a lighting up things further away, with a tighter more focused beam. This is commonly described as "throwy." Every once in a while you find headlamps that are good at both. Having the wrong sort is extremely frustrating. Using a tightly focused beam up close is counterproductive. The small bright spotlight bounces back to blind you and makes it difficult to see anything outside that point. Using a floody beam at range means you have to run the light at turbo and the battery runs down quickly. For example, Outdoor Gear Lab kind of slammed the excellent Zebralight H602 because it is a short range floody light, and for night hiking they wanted a throwier model.

Camping is one of the tricker cases. A throwy light makes it easier to find the next trail marker, but a floody light is more useful for chores around camp. Good headlamp designers know this and there are headlamps with dual emitters for both flood and throw. Keep an eye open for them. Some headlamps offer flip-down diffusers. These are more fragile and produce an uglier beam, but are extremely handy. The next best thing is to get a headlamp with a tight beam and make a simple diffuser from a chunk of plastic milk jug or other translucent material.

Lumens

Some general observations: 50 lumens in a throwy headlamp is usually enough on the trails, with the occasional full-power burst for scouting. 10 lumens in the same headlamp will be plenty for getting around camp. Sub-lumen modes are sufficient for reading at night. Bicycling will need 300-500 lumens. For a floody work headlamp, the magic number to keep in mind is 150-300 lumens. Around that output, the light will be as bright as the late afternoon sun. Or at least it will be that bright within arm's length. You'll be able to work as quickly as you can in broad daylight. Of course it is possible to get by with less, but you'll be moving slower and more carefully. Any more than 500 lumens isn't really necessary.

Colored LEDs

I could write an entire post just about this, but multicolored beams are a useless gimmick. The only place they make sense are for specific military applications. "Red is good for night vision" is a myth the same way that "carrots are good for night vision" is a myth. So if you care about preserving night vision, look for a light with a sub-lumen firefly mode. There is also a myth that red is better for battery life. This is blatantly false when comparing specs. Across all of the flashlights that I know of, red consistently performs at half the runtime of dim white.

Tint

Headlamps are typically used for extended periods of time, so it is advisable to choose a shade of white light that is easy on the eyes. The best options on the market now are neutral white or high CRI. These tints of white have a lower blue component and a more even spectrum. Colors look more natural. After experiencing good tint it can be hard to go back to the harsh blueish actinic light that is common in cheap LEDs.

Ultralight Hat Lights

I see a lot of questions about these. Hat lights are lightweight flashlights with a clip designed to fit the brim of a baseball cap. There are two general styles of hatlight: those that are designed to be a hatlight, and those which are a normal small flashlight that happens to have a reversible clip. The dedicated hatlights typically have bad LEDs with ugly blueish tint and poor runtimes. I still pack a small one in every first aid kit because there are times when any light at all is crucial.

Batteries

Dead headlamp batteries are pretty annoying. You'll always be in the middle of something when they go. And if the headlamp was your primary source of light, you'll be fumbling with batteries in the dark. These are my primary considerations when thinking about what sort of batteries my next headlamp should use.

It feels like a tautology to say that a light only dies when you are using it, but it takes on extra significance with a headlamp. You're wearing a headlamp to do stuff, stuff that otherwise wouldn't be possible in less light. All work must stop when the batteries go. At least until fresh batteries can be swapped in.

With that in mind, headlamps with hardwired batteries and micro-usb charging are a terrible idea. They are inexpensive and compact, but stay far away from them. They are marketed as more convenient, but think about what happens when they run out. Drop everything, take off the headlamp, plug it into a powerbank, twiddle your thumbs for a few hours while it charges, and finally resume whatever the task was. Hopefully it wasn't anything important or time-sensitive. Maybe the moon (or even the sun!) will come up first so you can get back to work a little faster. If you are really fortunate, the headlamp continues to operate when charging. You get to keep working but now you're wearing a heavy powerbank and be careful of catching the USB cable or breaking the micro-usb jack. Convenient, right?

If a light takes normal replaceable batteries then a dead battery can be dealt with in seconds.

Next, think about the process of actually changing the battery. Maybe there isn't any other light. You'll be pre-occupied with whatever you were doing. Changing the battery should be fast and simple. The simplest to change are lights that only use a single battery. With multi-cell lights there is a constant risk of mixing old and new batteries, or putting in one of the batteries backwards. Either of those mistakes can cause batteries to catch fire. This is a bad thing to have happen while the batteries are strapped to your head.

The best options for headlamp batteries are either a single AA battery or a single 18650 battery. The AA battery is compact and ubiquitous. A single AA is my favorite for camping. I can easily go 5 days on just one if I am mindful of using the minimum light. For a floody work light, the single 18650 does the job because it can provide the magic 150-200 lumens for 8 hours. Just one battery can provide daylight at your fingertips for an entire shift.

The absolute worst option for headlamps is 3xAAA. These have slightly more (12%) capacity than a single AA, but that isn't the whole picture. 3xAAA is 35% bulkier and heavier than an AA. The internal resistance is 5 times higher for 3xAAA,stealing much of that 12% extra battery life on the higher modes. Finally, 3xAAA allows manufactures to be extremely lazy with their circuit design. They can connect an LED directly to alkaline batteries without any regulating circuitry. This produces an intensely bright output and slowly tapers down to nothing, allowing ethically flexible headlamps to claim absurd run times.

(Seriously, read that article. It's good reporting.) And I am disappointed to say that little has changed since manufacturers have been called out on it. For example, compare the Peztl Tikkina to the Petzl Pixa 1. The first uses 3xAAA and claims 100 lumens for 60 hours. The second uses 2xAA while claiming 60 lumens for 3.5 hours. Now we know that 2xAA should have almost twice as much runtime as 3xAAA, yet the Tikkina is performing 30 times better by Petzl's absurd numbers.

If you want something a little more compact than 1xAA, consider 2xAAA or 1x16340 headlamps. If you want a little more power than 1xAA but aren't interested in li-ion, 2xAA headlamps are alright.

For more serious treks, like spelunking or mountaineering, then lights that use multiple 18650 cells start to look like a good idea. Basically any time that you can't assume that you'll have the ability to change batteries. For most people though these extreme headlamps will be an encumbrance.

Final Recommendations

So, do I have a list of the "10 Best Headlamps" for you? Of course not. Everyone's needs and situations are different. I hope I've been able to convince you that you'll want a headlamp that uses 1xAA or 1x18650. Maybe 2xAAA, 1x16340 or 2xAA if you have unusual requirements. And of course something with a sub-lumen mode or good tint is highly recommended. Beyond those guidelines you should read reviews and find what is a good fit for you.

One last note. If you go for an AA or AAA powered headlamp, don't use alkaline batteries in it! The gold standard is the Eneloop NiMH cell. They will last you a lifetime and are worth every penny. Alkaline cells will eventually leak and destroy your nice headlamp. Use alkalines only in emergencies and take them out of the headlamp during the day or for storage. When buying 18650 cells, avoid Amazon and purchase from a reputable re-seller instead.

Still have questions? Come to /r/flashlight and we'll do our best.