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Black Diamond Zenix IQ LED Headlamp REVIEW

Combines 1-watt LED technical lighting prowess with more economical standard 5 millimeter LEDs for non-technical pursuits.


by Rick Dreher | 2005-09-27 03:00:00-06


Black Diamond Zenix IQ LED Headlamp - 1
Black Diamond Zenix IQ.

  • Do you need a high-performance headlamp that's suitable for technically challenging nighttime activities?
  • Do you need a versatile light that supports in-camp chores and bedtime reading equally as well as it lights your nighttime cross-country adventures?
  • Do you prefer the simplicity of a single control switch?
  • Do you want a light that's inexpensive to power and coaxes a lot of life from a single battery set?
  • Do you prefer the balance of a headlamp with a separate battery pack in back?

If so, take a look at the Black Diamond Zenix IQ. The Zenix IQ does its part in pushing the LED headlamp envelope further. It combines 1-watt LED technical lighting prowess with more economical standard 5 millimeter LEDs for non-technical pursuits in one lightweight and easy to use package. At less than 6 ounces with batteries, the Zenix IQ is a trim powerhouse.


Headlamp Type

Separate lamphead and battery pack, cable-connected

Light Sources

Single 1-watt hyperbright LED with integral reflector plus two standard white LEDs, fixed beam angles

Test Run-Time Range

24 hours in two-LED, high mode; 2 hours of maximum output in 1-watt, high mode

Modes and Settings

Two operating modes with three brightness levels and one strobe setting (approximately 90/minute) each (total of eight modes)

Other Features

Adjustable lamphead angle, colored LED battery life indicator also acts as a flashing "find-me" marker light


Two AA alkaline (provided), lithium or rechargeable cells optional


Backpacking Light measured: 5.7 oz (162 g) with alkaline cells, 4.0 oz (113 g) without batteries. Manufacturer: same.

Head Strap

Double strap bucket-style, adjustable-length elastic, fixed bands

Battery Access

Battery cover locks with thumbscrew



What's Good

  • Bright, collimated 1-watt main LED
  • Frugal and effective two-5 millimeter LED floodlight
  • Lightweight and compact
  • Effective current management
  • Power indicator/"find-me" marker light
  • Inexpensive to power
  • Well balanced on the head

What's Not So Good

  • Measured battery life is less than Black Diamond claims
  • Lamphead and battery box not gasketed against moisture and dust
  • Straps not completely removable


Black Diamond Zenix IQ LED Headlamp - 2

The Black Diamond Zenix IQ is the second-generation of this pioneering LED headlamp. The Zenix IQ' bright output supports challenging technical nighttime activities. The new light is more than two-and-a-half times as bright as its predecessor - an astonishing increase - and added circuitry assures the low-output mode (using two 5 millimeter LEDs instead of the main 1-watt LED) significantly extends battery life (the original did not). The IQ model also adds three power levels per mode and a battery life indicator: a small LED on the side of the lamp module that changes color as the batteries wane. This LED doubles as a flashing marker light that makes it easy to find the Zenix IQ in the dark.


The plastic-bodied Zenix IQ sports a single collimated "hyperbright" white LED (probably a 1-watt Luxeon), flanked by a pair of the familiar 5 millimeter white "superbright" LEDs. It operates in two modes: Mode 1 uses the main 1-watt LED and Mode 2 uses two auxiliary 5 millimeter LEDs (the three never operate together). Mode 1 provides a very bright pencil beam; Mode 2 provides a dimmer, more even and somewhat wider beam. Each mode has four settings: high, medium, low and strobe, giving eight total combinations. The strobe operates at the brightest output level in either mode. A single rubber-covered switch set beneath the lamphead controls all modes and settings. A full click turns the Zenix IQ on and off, switching between the two modes in turn (i.e., on Mode 1, off, on Mode 2, off...). With the light in the desired mode, clickless half presses roll through the four settings from high through strobe, then high... etc. When switched on, the IQ remembers the last mode used, but not the mode level.

When folded closed for storage, the mount plate protects the switch against accidental use. The switch can be operated wearing thin gloves and mittens, but mostly defied our attempts wearing thicker fare. The Zenix IQ's 1-watt LED's clear acrylic lens is slightly recessed in the housing to help protect it from scratching. The two 5mm LEDs are also recessed for protection; however, their wells also accumulate debris over time and require occasional cleaning. The battery monitor/ find-me light resides behind a tiny rectangular window on the lamphead's left side.

Surprisingly useful, the battery minder/find-me light uses a tiny three-color LED - green, orange and red - behind the small window. Whenever the IQ is switched off, the light blinks about twenty times a minute, making it quite easy to locate it in the dark or buried inside a backpack. Worrywarts can take comfort in Black Diamond's claim that the light will happily blink away for five years on a set of batteries.

In battery condition mode - whenever the light is switched on - the LED usually glows steadily. Green indicates the batteries are either new or relatively fresh. Per Black Diamond, at about 50% residual life the green switches to orange and the IQ's main light blinks twice as an alert that this has occurred. Thereafter, the red LED is displayed. When fresh batteries are first inserted, the orange indicator blinks several times as the IQ self-calibrates, then the light switches to steady green. It will occasionally self-test when switched on even if the batteries haven't been accessed. In our tests, we found this system rather helpful, although there's obviously a large "gray"' area between new and 50% batteries, and likewise between 50% and downright dead. At its most basic, before leaving on a trip it's easy to check whether to replace the batteries: green literally means, "go." Fuel cartridges should be this communicative!

The Zenix IQ's separate battery compartment is connected to the lamphead by a power cable routed around the headstrap's right side. Moderate tugs on either end of our sample's thickly insulated cable didn't pull it from its moorings, but note that the cable isn't provided with stress relief at the ends. The 3/4 inch-wide elastic head strap threads through a baseplate that's connected with a hinge to the bottom of the lamphead, providing a vertical angle adjustment (limited in range to straight-ahead). The bolt-and-nut hinge can be tightened using a flat-blade screwdriver, if needed. In our test it held the lightweight lamphead's angle throughout (trail runners take note). The adjustable-length head strap is long enough to fit over a helmet. The top or bucket strap cannot be removed without some seam-ripping, so its use isn't optional as with some bucket-style headstraps.

The battery box resides at the back of the headstrap. The hard-plastic box is curved to follow the head's contours and is padded by a couple of pieces of foam and the elastic headstrap. It's comfortable and not particularly noticeable, other than reading while lying face up. An advantage to this arrangement is that batteries can be kept warm under a parka hood, extending their life in cold weather.

The battery compartment opens by unscrewing a slotted, knurled plastic and metal thumbscrew and swinging the cover open. The cover completely separates from the compartment and is held captive by the top strap. The thumbscrew slot allows use of a screwdriver, coin or other tool - a nice option for cold, wet hands - and the screw is captive to prevent its loss in the field. The battery compartment has a metal threaded insert to accept the thumbscrew, which should prevent damage from over-torquing the screw. We didn't need to use a tool to open or close the compartment in our tests, and even heavily mittened hands could accomplish this feat - bravo! The battery box (and lamphead) is not sealed with a gasket or o-ring and will eventually take on water if immersed. This is not a light to use around saltwater. (Black Diamond's IPX-4 waterproof rating claim is that the IQ will resist a water spray from any angle.) Batteries stay in place when the compartment is open and it's easy to tell the correct alignment during replacement.

The Zenix IQ is current-regulated, which is perhaps its most important advancement over its immediate predecessor, the Zenix. The circuitry does a laudable job steadying light output except in Mode 1, high. It also noticeably steps the IQ down to the next lower level as battery wear progresses and, as promised, giving an advance blink to alert the user. This blink can frankly be a little startling if you're not expecting it - fresh batteries before the nighttime high-wire act are strongly recommended. As with all LED lights, the Zenix IQ's color temperature doesn't change as output drops.

Tracking the Changes

The Zenix IQ is a follow-on model to the Zenix, which came out scarcely a year before. It has several differences and one major performance advance:

Differences Between Zenix IQ and Zenix Headlamps
Zenix IQZenix
BatteriesTwo AAThree AAA
Current regulation?YesNo
Battery meter/find-me blinker?YesNo
Weight with batteries5.7 oz (162 g)4.5 oz (128 g)
Battery life max/min strobe (manufacturer)8-300 15-100
Center beam brightness (at 2 ft)1150 lux438 lux

That's a lot of added value for a piddling extra three dollars.

Lab and Field Performance

We measured beam center and off-center performance for all modes and levels, using a light meter.

Zenix IQ Output in the Six Continuous Settings
Measured in Lux from 2 feet*, fresh Alkaline Batteries, Room Temperature (75 °F)
SettingMode 1 (1-watt LED)Mode 2 (two, 5 mm 5 mm LEDs)
Beam center1 ft off-centerBeam center1 ft off-center

Beam Configuration and Usefulness

The Zenix IQ beam has a bright yellowish center spot surrounded by a broader, dimmer blue-white halo. The beam pattern and color are quite different from our test Princeton Tec EOS; surprising, since they use very similar emitters. Both, however, seem equally useful in the field. The halo surrounding the center spot in the Zenix IQ beam is a somewhat irregular series of bands. As the test data show, it is effectively a pencil beam with a sharp cutoff, good for long beam throw and technical nighttime navigation, not so good for cooking and reading. For those more prosaic campsite activities, the IQ's two 5 millimeter white LEDs provide quite adequate light without dazzling the eyes, and stretch the batteries at the same time. The 5 millimeter beam still isn't particularly wide but the center and edges vary far less than the 1-watt beam, so the effect is one of a floodlight.

We didn't generally require the Zenix IQ's brightest setting (Mode 1, high) for more than a minute or two a night; we found that most technical activities (sketchy trails, basic cross-country) could be performed using medium. Camp chores and nighttime reading are fine using Mode 2, accessing the three levels as the requirement varied. Mode 2, low is adequate for reading and preserves night vision the best of the six options.

Runtime Tests

Black Diamond Zenix IQ LED Headlamp - 1
Black Diamond Zenix IQ Intensity vs. Time (Output) Graph.
Click this link to see a larger version of this graph.

We chose to test three of the IQ's six continuous modes: Mode 1, high and medium and Mode 2, high. The graph shows that the current regulation holds the output steady, except for an initial drop in Mode 1, high. The Mode 1 graphs also demonstrate the stepping down that occurs as battery life drops. Mode 2, high output was rock steady for about a day, before winking off. All tests were with alkaline batteries at room temperature (75 °F).

We found run times to fall far short of Black Diamond's estimates (see the following table). Since the Zenix IQ shuts completely off rather than lingering dimly for days as with some LED lights, we can't know where the discrepancy comes from (sample variation?). We're not disappointed at our test IQ's performance, just puzzled at the great difference. What is gratifying is how effective the current regulation is in maintaining output.

Run Time, Specified and Measured
Mode 1 (1-watt main)
Manufacturer Specification
Mode 1 (1-watt main) Backpacking Light Measured
Mode 2 (two 5 mm auxiliary)
Manufacturer Specification
Mode 2 (two 5 mm auxiliary)
Backpacking Light Measured
High8 4.560 23.5
Medium19 5.5120-

Shortcomings and Suggestions

The Zenix IQ has few obvious faults, just strong competition, and Black Diamond deserves credit for following up the very good Zenix with the clearly superior Zenix IQ so quickly. Nevertheless, here are a few suggestions for improvement:

  • Make the top strap removable
  • Allow the lamphead to swing upward, past horizontal for overhead illumination
  • Add intensity memory to the mode memory
  • Gasket the lamphead and battery box and reinforce the cable entry points for true waterproofness
  • Enlarge the switch diameter to ease operation with mittened hands


Black Diamond Zenix IQ Headlamp - 3

The Black Diamond Zenix IQ is clearly a better headlamp than its predecessor, the Zenix. While it's slightly heavier and operates a shorter time in high-high mode, it's significantly brighter and offers more features. The addition of current regulation means the IQ can maintain steady light output longer as batteries wear and the switch to two AAs from three AAAs makes the light less expensive to power, with little weight penalty.

Comparing the main LED with the Princeton Tec EOS, our current favorite compact LED headlamp, the Zenix IQ is not quite as good a performer, either in the quality of the main beam or in battery life. It's also not submersible like the EOS and doesn't have a removable strap. However, the IQ offers a true floodlight/task light capability and the welcome battery meter/find-me light. For users who prefer a bucket-style strap and the superior balance and battery warming abilities of a separate battery pack, the Zenix IQ may get the nod.


"Black Diamond Zenix IQ LED Headlamp REVIEW," by Rick Dreher. (ISSN 1537-0364)., 2005-09-27 03:00:00-06.