The Black Diamond Zenix IQ is a 2 LED/Luxeon headlamp with 8 modes of operation. The bezel and switching mechanism are on the front of the user's head and the battery compartment is in the rear. Both sections are attached by a cable which wraps around the user's right side and the unit uses a 3 point elastic fully adjustable suspension system to attach to the user's head.

Two 5mm LEDs rest in recessed dimples on either side of a single Luxeon I emitter in the center of the bezel. The Luxeon LED uses an internal reflection collimating lens to produce a focused spot. The bezel is vertically adjustable 90 degrees and when pivoted all the way down the switch is protected from accidental activation. The battery box is easy to access without having to remove the straps. The unit runs on 2 AA cell batteries. Waterproofing is completely absent on the battery box.

The straps are elastic and are very easily adjustable. The strap attachment rings have gaps cut in them so that the straps can be easily removed for cleaning or replacement. The cable that runs between the bezel and the battery box is held on to the straps by two clips which are unnoticeable from a comfort standpoint.

On the side of the bezel is a clear window which displays a blinking "find me" LED when the lamp is off. The LED blinks about once every 2-3 seconds. When the lamp is on, the LED on the top shows different colors based on battery life remaining. Green means more than 50% remaining, yellow means between 50% and 20% remains, red means less than 20% remains. Black Diamond recommends changing the batteries when it gets to red. Since you cannot see the indicator when you are wearing the lamp, the main lamp blinks once when switching from green to yellow, and twice when switching from yellow to red.

The bezel contains the two 5mm LEDs, Luxeon LED and optics, and switching mechanism. There are 2 primary modes of operation and 6 sub-modes within them. A firm click turns on the headlamp in either 5mm LED or Luxeon mode. A second click turns it off. Third click turns it on in the opposite mode from before (5mm LED or Luxeon) and fourth is off again. While in either mode, a half-click will adjust the brightness. For both the 5mm LEDs and the Luxeon, the modes are high-med-low-blink which then repeats. Turning off the lamp for more than 5 seconds causes the light to turn on again later in the same mode (5mm LED or Luxeon LED) at maximum brightness.

Output is in the form of a wide spill of light from the 5mm LEDs for close work and a tight spot from the Luxeon bulb for distance work. On both modes you get a fairly smooth beam with few artifacts. As is to be expected, the 5mm LEDs are white but appear to have a bluish tint. The Luxeon LED in the unit received appears to have a very slight purplish tint (despite the photograph below) which is especially noticeable when switching from the 5mm LEDs to the Luxeon. However, your eyes rapidly become adapted to the color temperature of the Luxeon and the tint becomes completely unnoticeable.

   
Luxeon beam at one meter at target center and LED beam (LED beam enhanced for clarity)

Runtime Plot: A rather unusual runtime plot resulted from running the light on high with the Luxeon LED. At the 2 hour mark it undergoes a distinct step-down to a lower level of output, instantly losing about 30% of its brightness. After that it maintains the lower level of output for about another 2½ hours before dropping again to a very low output level. I would expect similar performance on medium and possibly low level as well. It appears that Black Diamond's runtime estimate, although "accurate" based on their disclaimers of what "usable output" is considered, are a bit misleading to the consumer since bright output on high mode is only really maintained for about 2 hours before dropping to a secondary level of output. Still - pretty darn good for just 2 AA cells! I'd bet that with lithium AA cells the light would perform better and the curve would look very different.

Runtime completed with included "Energizer" batteries. More information on runtime plots is available HERE.

The switch is a simple click switch covered with a rubber cap. It rests under the bezel so most folks will press it with their thumb when they grab the light with their hand.

Black Diamond says in the instructions that this headlamp is tested to IPX-4 water resistance and continues to work when sprayed water. They do state that water will get in the headlamp and it will need to be dried, but it will work. There are no visible seals in the battery box. The bezel has an O-ring at the primary separation and a rubber seal at the penetration point of the cable.

Ergonomics: Generally seems to fit well with no serious pressure points. I think the battery box may get a wee bit irritating pushing on the back of the head, but that's pretty typical for most headlamps. The bezel angle adjustment does not ratchet into place and I found mine moved too easily. There is a nut-and-bolt arrangement at the pivot hinge which you can tighten to match your preferences.

For batteries this lightweight unit runs on 2 AA cells. Either alkaline or lithium are permitted by the manufacturer. There is a thumbscrew in the back of the battery box. Spin it off with your thumb (it has a retainer so it doesn't get lost) and hinge open the compartment. The lid is attached to the central strap while the rest of the box is attached to the side straps. The box lid can come completely off. Insert your batteries and close the box. I found it was best to pinch the box shut so it clicks into alignment and then tighten the thumbscrew.

Batteries are included. No spare bulbs are needed for this light since it uses entirely solid state lighting.

What I Liked: Water resistant (splashable), Long battery life option available, Good output, Easy battery change, Battery level indicator, "Find me" blinking LED

What I Didn't Like: Should be more water resistant in my opinion.

Other Things I Noticed: Angle adjustment needed tightening.

Conclusions: Great lightweight headlamp! No bulbs to change, provides flood and spot options, long battery life possible by using the low output modes, and only runs on 2 AA cells.

Quick Facts Table: