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Reviews > Lighting > Headlamps - LED > Black Diamond Iota Headlamp > Test Report by jerry adams

August 11, 2017



NAME: Jerry Adams
EMAIL: jerryaadamsatyahoodotcom
AGE: 63
LOCATION: Northwest U.S.
HEIGHT: 6' 2" (1.88 m)
WEIGHT: 195 lb (88.50 kg)

I started hiking about 50 years ago. My first backpacking trip was about 45 years ago. I currently try to do one backpack trip of 1 to 5 nights every month (which can be tricky in the winter). Mostly I stay in the Western half of Oregon and Washington. In recent years I have shifted to lightweight - my pack weight without food and water is about 12 lb (6 kg). I make a lot of my own gear - silnylon tarp-tent, bivy, down bag, simple bag style pack.



Manufacturer: Black Diamond
Year of Manufacture: 2017
Manufacturer's Website:
MSRP: US$39.95
Listed and Measured Weight: 1.9 oz (56 g)
Size: 1.25 x 1.25 x 2.125 inch (3 x 3 x 5.5 cm) outside dimensions not including the strap

The Black Diamond Iota Headlamp is a LED headlamp with a built in rechargeable Lithium battery. This LED headlamp is a little smaller and lighter than other LED headlamps I've used. Typical 3 AAA headlamps with Lithium batteries weigh maybe 0.5 ounce (15 g) more. With disposable battery headlamps, the batteries last me for several trips. I'm not sure how much I have left so I typically carry a spare set, which weighs another 0.85 ounces (24 g). With the Iota, I'll just charge it before each trip and not have to carry any spare batteries.

Headlamp with strap fully extended:

On/off switch is to the left of the picture, dimmer switch to the right of the picture:

USB charging port cover open on the left of picture, on/off switch to the right, lens on top, charge indicator light between the lens and USB charging port:

Front view of light - beveled lens cover at center, charge indicator at right, USB charge port cover opened to the right of that:

The front lens has about 20 rows x 20 columns = 400 total small pyramid shapes. I assume this is to make a more even, broad illumination. Other LED headlamps I've tried have a smaller circular area of high illumination. Testing will verify this.

To turn the light on, press and release the on/off switch. Press and release again to turn it off. Press and release three times to put into strobe mode. Press and hold for 4 seconds to lock (so it won't turn on in the pack). Repeat to unlock.

Added with Long Term Report:
To dim the light, after turning it on, press and hold the on/off switch. It will start cycling between dimmer and brighter, Let go of the on/off switch when the desired brightness is reached. To make that the default brightness, plug into USB charger. Unplug from USB charger. Within 25 seconds, Push and hold the on/off button. It will flash blue, then yellow. While it's flashing yellow let go of the on/off button.

Tap the dimmer switch to go between bright and dim.

Added with Long Term Report:
If the default brightness is set, then tapping the dimmer switch will go between that and full brightness.

Bright - 150 lumens, 40 meters (120 feet), 2 hours.

Dim - 4 lumens, 8 meters (24 feet), 20 hours.

The head strap is 2 feet (61 cm) around fully extended. 14 inches (35 cm) around minimum. It's elastic so it stretches a little bigger than this. The strap is 3/4 inch (2 cm) wide - this is a little narrower than typical LED headlamps I've used.

The headlamp is IPX4 waterproof (splash-proof - can't be submerged).

When charging, the charge indicator light is:
green flashing once per second - charging
green flashing twice per second - charging the last little bit
green - charge complete

When the light is first turned on, the charge indicator light is:
green > 50% charged
orange 25 - 50% charged
red less than 25% charged

The light can be tilted up for distant illumination, can be tilted down to see close up, and can be adjusted anywhere in between, like other headlamps I've used.

It comes with a short cable for charging - 0.5 ounces (14 g). There's a standard USB male plug that connects to a charger, and a micro USB male plug that plugs into the headlamp.


This looks like a really nice headlamp.

It seems well made and has a solid feel.

I tried the headlamp on. It seems comfortable. Everything works. I like the light weight.


I am really liking the Black Diamond Iota headlamp.

It is a little lighter weight than other LED headlamps I've tried.

It's rechargeable so I can fully charge before a trip and not have to carry spare batteries.

I'll be testing this on one trip per month for the next four months. About 6 nights per trip.

Look forward to my follow up report in a few months.



04/21/17 - 2-night backpack, 4-night car camp on the Deschutes River in north central Oregon. 48 miles (77 km), 650 feet (200 m) elevation gain, 32 to 70 F (0 to 21 C).

05/16/17 - 2-night backpack, 4-night car camp at Sand Point and Graves Creek in northwest Washington. 46 miles (74 m), 2400 feet (730 m) elevation gain, 45 to 65 F (7 to 18 C)

06/01/2017 - 2-night backpack in Trinity Alps in northern California. 21.5 miles (35 km), 2600 feet (800 m) elevation gain, 48 to 75 F (9 to 24 C)


First I did some testing at home.

I fully charged the Iota and then ran it on high intensity. The burn time was 8 hours. This was much more than the spec'd 2-hour burn time. The charge indicator was red the last 30 minutes. I never saw an orange charge indicator as mentioned in the instructions. They specify that it shows orange for 25-50% and red the last 25%, but I only saw red the last 6% or so. The headlamp was very bright. I compared it to another LED headlamp I have with slightly less lumens and the Iota seemed a little brighter, so I think maybe the Iota achieved the 150 lumens it's spec'd at. Another thing I noticed about the Iota was that the illumination was very broad and uniform compared to the more spotlight illumination of my other headlamp.

I charged the Iota again. It took 2 hours to charge, less than the spec'd 3 hours. The charge indicator blinked green while charging but I never saw rapid blinking for the last bit of charging as mentioned in the instructions.

I then ran it on low. The burn time was about the same 8 hours as high intensity. This was much less than the 20-hour spec. It was about half as bright as high intensity; I'd estimate about 75 lumens. The spec is 4 lumens.

Then I did my normal field testing.

I hiked 142 miles (230 km), did 6 nights of backpacking, and 8 nights of car camping.

Mostly, I just used the light around camp. The test period was during the season of long days and short nights so it was almost always fairly light when I wasn't sleeping. I used the light a few times at the end or beginning of the day, and if I needed it briefly get up at night. I used it at low intensity. There was a lot of illumination, way more than necessary. I would have liked it if the low setting was 4 lumens as advertised.

I never came close to completely discharging the light on my longest trip, which included six nights of usage. I just recharged it before the beginning of each trip. I carry a USB charging bank anyway to charge my MP3 player. If I used the Iota a lot it would have been easy to recharge it.

The light was very bright, with a broad, fairly uniform light. This picture gives an idea what the illumination is:


I was able to easily tighten and loosen the headband. It stayed in place after adjustment, but it seemed like it might slip. Aesthetically, I'd prefer the adjustment was a bit tighter so it wouldn't feel like it was about to slip, but this was no big deal.

I was easily able to rotate the headlamp up or down so the light would point further away or closer. It stayed in place well.

I was easily able to push the on/off button.

The button on the side to adjust intensity level was not so good - there's no tactile feedback so it was difficult to figure whether it worked or not, except I could see by the light, so this didn't much matter.

The charge indicator LED didn't work as advertised, but that made no difference to me. It did correctly indicate when it was charging and when it was complete which is all that's needed.

One thing I didn't do a good test of, which I'll remedy in the Long Term Test period, is to do a long walk at night.


Overall I was satisfied with the Black Diamond Iota headlamp.

All the basic functions worked fine - tightness of headband, head rotation for distance adjustment, on/off, time to charge and discharge. The broad uniform illumination was great.

In my opinion, the one big defect with this headlamp is that the low intensity setting (5 lumen) was much brighter than spec'd. This means the battery won't last as long as advertised, and when I want to get up at night it's so bright it bothers other people.



June 15, 2017 - 4-night backpack, 2-night car camp in Trinity Alps in northern California. 34 miles (55 km), 7000 feet (2000 m) elevation gain, 45 to 75 F (7 to 24 C)

July 1, 2017 - 4-night backpack, 2-night car camp on Mt Hood in north central Oregon. 50 miles (80 km), 9000 feet (2700 m) elevation gain, 48 to 85 F (9 to 29 C)

August 1, 2017 - 5-night car camp at southwest Washington coast. 25 miles (40 km), 58 to 75 F (14 to 24 C)


During the Field Report and Long Term Report periods I did 31 nights using the Iota headlamp. This was during the period of the year when the nights are shortest, but I got enough testing in regardless. Mostly, I just used it occasionally at night. I also did some night hiking just to test the Iota.

At the brightest setting, the Iota is great. Very bright. I could see at a large distance to see the trail, or figure out where it went. The only problem is that it was unnecessarily bright for camping. It annoys other people. And it is blinding if I looked at it, I think it could cause vision damage.

My only problem with the Iota was that the dim setting wasn't very dim, but on the last night of my testing, I figured out how to dim it more. If I turn it on, then push and hold the on/off button again and I can make it fairly dim. And if I plug and unplug from USB I can make that the default whenever I turn on the Iota. It's kind of an obscure user interface, in my opinion, but after going back to the website, there were some videos that made it more clear. The user manual that came with the Iota was not clear. I think it would be better if I could just push the on/off button again to cycle through intensity levels like most other headlamps I've used.

After my last trip I tested how long the battery would last on dim. It was 31 hours, much better than the 20 hour spec. The brightness was about the same at the end, as the beginning of this test.

The strap continued to function well. It was fairly easy to tighten to the desired position but didn't slip. It didn't show any signs of wear. The head rotated well to adjust between close and far away illumination.

Wearing at Trinity Alps:

After the LTR period I took another trip using the dim setting. This worked really good.


The Black Diamond Iota is a rechargeable LED headlamp.

The bright setting is very bright, more than enough for any night hiking that I'd do.

The dim setting is plenty for most uses.

The user interface to dim the light is very obscure and not well described.

The Iota burn time on high was 8 hours, better than the 2 hour spec. The burn time on low was 31 hours, better than the 20-hour spec.

The Iota is very light weight.

I think this will be the headlamp I use for trips in the future. I have several 3 AAA headlamps but they're heavier, plus I have to carry spare batteries because I don't usually know how charged the main batteries are.

Thanks to Black Diamond and for letting me test this.

This report was created with the Report Writer Version 1. Copyright 2017. All rights reserved.

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