Black Diamond Iota Head Lamp Review

Tim used a Black Diamond Iota head lamp during our Pacific Crest Trail thruhike in 2018.

Specs:

Lumens: 150
Weight: 1.9 oz (56 g)
Max Distance: High beam 131 feet (40 m) / Low beam 23 feet (7 m)
Water resistant (IPX rating: x4)
Battery Life: Low beam ~40 hours / High beam 2 hours
Internal Battery: Lithium ion, micro USB rechargeable

Pros:

Lightweight
USB rechargable
Small
Strong beam
Dimmable
Reasonable battery life
Recharges quickly

Cons:

No red light
Battery life not suitable for extended night-hiking

Size and weight

According to 0ur kitchen scale, the Black Diamond Iota is 1 7/8 ounces including the headband. That makes it one of the smallest and lightest rechargeable headlamps on the market. That’s why I bought it. It sacrifices on fancy features in order to be small, but for a thruhike fancy features aren’t needed. I needed light at night, portability during the day, and durability/dependability. The Black Diamond Iota was perfect in these areas.

Black Diamond Iota size - compare to lighter — The Black Diamond Iota is not much larger than a Bic lighter. This makes it convenient to store just about anywhere in a backpack.

Black Diamond Iota weight. 1 7/8 oz — At only 1 7/8 ounces, the Black Diamond Iota is one of the lightest headlamps on the market.

Rechargeable

The Black Diamond Iota is charged with a micro USB cable. It takes an hour or so to go from no charge to a full charge. It has a small light that turns green when charging is complete. Renee and I both had nice headlamps before hiking the PCT, but they were powered by AAA batteries. For a thruhike, rechargeable headlamps seemed important–carrying spare batteries solely for our headlamps seemed like unnecessary extra weight, and finding batteries for sale in resupply towns seemed like a hassle. We were right. Rechargeable headlamps were very convenient, especially since they could be charged from the same power bank that we had to carry either way for our phone and GPS watch.

Black Diamond Iota -- Micro USB port — A micro-usb port is located on the side of the Black Diamond Iota. There is a plastic flap to protect the port from rain.

Buttons

The Black Diamond Iota has an easy to find power button on the top of the unit. A short press turns it on or off, and holding the button down dims the light. When it reaches the most dim setting, the light does a quick flash before increasing in brightness, which is convenient for setting it to full dimness for conserving battery. When dim, a short tap to the side of the unit brings it up full brightness, and another tap brings it back to your previous dim setting. There is no button–you just tap the headlamp. This is convenient when you need to see well for a short time, but you are mostly using it on dim.

I mostly kept the headlamp in the hip-pouch of my backpack. On a few occasions, the light turned itself on in the pouch and the battery died on its own. This happened so rarely that it wasn’t a problem, but it is possible.

Black Diamond Iota main button — This button on top of the Black Diamond Iota is pressed to turn the unit on/off, or it is held down to adjust the brightness.

Black Diamond Iota side that can be tapped — The side of the Black Diamond Iota can be tapped to temporarily switch to full brightness. There isn’t a button here, just some sensor that knows when you quickly tap it with your finger.

Battery Life

I typically got about a week of battery life out of the headlamp during our PCT thruhike. This depended on how much I was using the headlamp, but since our schedule mostly revolved around waking and sleeping with the sun, it was mostly used for a few minutes a day just before sunrise and just after sunset. The specs from black diamond seem pretty accurate based on my experience — around 40 hours at completely dim or about 2 hours at completely bright. Around camp and in the tent, full or partial dimness was fine. But on the few occasions we tried to night-hike it was very nice to use the light at or near complete brightness. Therefore, hikers who rely on their headlamps for extended night hiking may want something with a longer battery life.

Adjustability

The head-band of the Black Diamond Iota is very easy to adjust. You just slide it to your head-size. After a few days of use it tends to loosen up a bit, so you just slide it back. The tendency to loosen over time is a fine trade-off for such simple adjustment. The lamp itself can be pointed straight-ahead for walking or pointed downward for close-at-hand tasks (such as sewing my pants and shoes in the tent after dark). This adjustability was very convenient and I used it all the time.

Black Diamond Iota pointed straight ahead — Headlamp pointed straight-ahead

Black Diamond Iota pointed down — Headlamp pointed down for close-at-hand tasks

Black Diamond Iota head band — The plastic clasps on the headband are very easy to slide to adjust the headlamp to different head-sizes or for use on top of a hat.

Durability

All of the pictures in this review were taken more than 1-year after I purchased the Black Diamond Iota. The year included 142 days of constant use during our PCT thruhike, additional use on several shorter hiking and camping trips, and regular use at home. The headlamp is dirty, but it works as well as the day I bought it. The battery life is as long as ever, the buttons work perfectly, the headband elastic is intact, and it is still fully adjustable. I am confident it will work for several years to come.

Summary

I was very pleased with the size, weight, durability, adjustability, and brightness of the Black Diamond Iota. Hikers who expect to do a lot of night hiking may want to consider a headlamp with a larger battery, but battery life was never an issue for me on the trail. I am very pleased with this headlamp and I plan to use it again on future thru-hikes.

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