Gear Review: Black Diamond Iota Headlamp

Black Diamond Iota headlamp
Black Diamond Iota headlamp

Ultralight Rechargeable Headlamp
Black Diamond Iota
$40, 2 oz.

Even as backcountry headlamps continually shrink without compromising brightness—indeed, today’s ultralight models keep getting more powerful—my first impression of Black Diamond’s Iota is how darn tiny it is. Smaller than a golf ball, it’s nearly unnoticeable on your head: After turning it off, you could forget you’re wearing it. This two-ounce beacon also represents a leap forward in the affordability of rechargeable headlamps. While the Iota’s relatively short burn time on a full charge limits its versatility, it will appeal to people who want an affordable, ultralight, rechargeable headlamp for outings of up to two or three hours.

BD says the Iota’s single TriplePower LED bulb projects 150 lumens at max brightness for more than 100 feet. Testing it on fall hikes in Great Smoky Mountains National Park and the North Cascades National Park Complex, and while car-camping in Idaho’s Sawtooth Valley, I found that the oval beam of light it throws illuminates a broad area well for perhaps half that claimed distance; beyond that range, dark forest and land swallow the light because the beam expands with increasing distance. Still, it adequately lit a pitch-black, forested section of the Appalachian Trail for me to hike that steep, rocky path before dawn, and it casts enough light for trail running.


Black Diamond Iota
Black Diamond Iota headlamp

Unlike some rechargeable headlamps, the Iota does not use batteries. A full charge of its lithium ion battery lasts 40 hours at the dimmest setting—really only bright enough for tasks at hand distance or reading—or two hours on high. BD says a charge lasts an average of three hours. Thus, the Iota’s only practical for relatively short, multi-day trips, unless you’re also carrying a portable, solar-powered recharging unit and you can count on consistent sunshine. But the Iota recharges via mini-USB in three hours (during the day or overnight) from a variety of devices, making it useful for short adventures or when you’re confident of needing light for only part of your day, like an early-morning trail run or hike.

Holding the power button down controls the dimming function. The Iota’s PowerTap technology allows you to instantly switch between the most-recently set level of dimness and max brightness by simply tapping the right side of the casing (marked by a bulb icon). Click three times quickly to engage white strobe mode. There is no red mode. The Iota’s lockout feature prevents it accidentally turning on in a pack: Hold the power button down for several seconds; a blue light flashes when lockout is engaged. Hold the power button down again to turn it back on. A power meter indicates remaining battery life in three levels—imprecise, but adequate. The IPX4 rating means it can withstand splashes of water or a light drizzle, but don’t let it get soaked. Lastly, the comfortable, adjustable strap will help you forget it’s on your head after you turn it off.

For multi-day trips or activities like mountain biking and alpine climbing, you’ll need a brighter headlamp with a much longer burn time, or battery life on a full charge. But for early-morning or evening trail runs, hikes, or schlepping back to the car after getting off a climb at dusk, the Black Diamond Iota will light your way without creating more battery waste or setting you back as much as other rechargeable lights.

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See all of my reviews of headlamps, hiking gear, and backpacking gear at The Big Outside, and my stories:

The Simple Equation of Ultralight Backpacking: Less Weight = More Fun
Gear Review: The Best Gear Duffles
My Top 10 Favorite Backpacking Trips
10 Tips For Getting Outside More

NOTE: I tested gear for Backpacker Magazine for 20 years. At The Big Outside, I review only what I consider the best outdoor gear and apparel. See categorized menus of all of my gear reviews at The Big Outside.

—Michael Lanza


Hi, I’m Michael Lanza, the creator of The Big Outside, recognized as a top outdoors blog by USA Today and others. I invite you to get email updates about new stories and gear giveaways by entering your email address in the box in the left sidebar, at the bottom of this post, or on my About page, and follow my adventures on Facebook and Twitter.

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