UPDATE: Well, I'm an idiot sometimes. I misread my own numbers and falsely stated that the ArgoHP is not brighter than the original Argo. WRONG! It IS brighter. My OOPS! Corrections to the review have been made.

The Streamlight Argo HP (High Performance) is the next generation of the Argo headlamp from Streamlight. This version uses a Luxeon Star side emitting LED for light and contains a digital regulation circuit which provides 2 separate levels of brightness as well constant output from the LED for a considerable amount of time. Instead of 3 AAA alkaline cells, the Argo HP runs on two 123A lithium cells for better performance in cold weather and lighter weight. When compared to the original Argo, the "High Performance" part of this headlamp comes into play in two areas; both longevity and output!.

The body of the Argo is a tough black polymer with a rubberized ring surrounding the bezel for impact protection. The bezel is on top and the battery compartment rests below. The body of the light is attached to a forehead plate which is held on the head by a fully adjustable 3-point strap system of fabric elastic bands. The back of the forehead plate has a recessed foam pad for comfort. The light body is attached to the forehead plate by a ratcheting hinge to the forehead plate which allows you to direct the light where you need it. Included in the package is a fully adjustable two-point rubber hard-hat band as well. Straps are easily removed from the plate as a result of gaps molded into the attachment points. Unlike the original Argo, there is no battery level indicator on the unit.

The bezel contains a shatterproof polycarbonate lens, a partially textured silvered plastic reflector and the circuitry to drive the Luxeon Star LED. The light is set to a permanent focus and provides a wide spot of light. Since the LED and circuitry is practically impervious to impact and the bulb should never fail, there should never be a need to open up the bezel. Inside is the very compact circuit and LED.

Light output was in the form of a smooth wide spot with some minor artifacts. Running the light on high will go through two 123A batteries in about an 4.75 hours while low power will give you light for about 20 hours (advertised). Digital regulation circuitry helps maintain constant or near constant brightness throughout the battery life.

   
Beam at one meter at target center and at target edge to show spillbeam.

Runtime Plot: Well, Streamlight was right on the money this time! They claim 4.75 hours on high and I read about 5 hours before the headlamp drops out of regulation. Nice flat regulated plateau, too. Nearly constant brightness during the first 5 hours of use on high.

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

The switch is a simple rubber covered click switch which rests on top of the light. First click turns the light on low, second click gives you high. Dimming appears to be accomplished by current regulation instead of the more common "pulse width modulation". The result is that you will not see the sometimes annoying strobing of the LED which results from PWM regulation. The only thing you'll see is nice smooth output.

The light is sealed at the battery compartment and the bezel with well-lubricated O-rings. The light should be considered "dunkable", but is not rated for intentional submersion in water. If it does get wet inside, disassemble as much as possible without tools and let it dry out.

Ergonomics: The Argo HP is a little front heavy, but not excessively so. This is typical of headlamps with the batteries in the front instead of in a rear compartment. Of course the advantage is that there are no cables running around your head that can get caught on branches or obstructions.

The two 123A lithium batteries are dropped directly into the battery compartment under the bezel of the light. Simply unscrew the labeled cap on one end and place the cells in positive first.

Included with the headlamp in addition to the three point elastic headband is a two point rubber strap for attaching the headlamp to a hard-hat.

What I Liked: Water resistant, Variable output, Tough/impact resistant, Good output, Regulated, Easy battery change, Lightweight, Comfortable

What I Didn't Like: Nothing worth mentioning.

Other Things I Noticed: Slight artifacts in the beam but nothing serious. Pila rechargeable cells will fit in this headlamp and it will run with them. See this chart for more info. Output will not match using primary cells, but it is still very good.

Conclusions: A great little headlamp. Output is pretty good on "high", and more than adequate for most tasks on "low". Switch it to "high" if you really need it, or leave it on "low" if you need to conserve batteries. Somehow Streamlight managed to get both more output and more battery life out of this critter compared to the original Argo. Overall I like it and I think it's battery conservation ability and output selections will more closely match the needs of individuals who utilize headlamps for most common tasks compared to the short battery life of the original Argo.

Quick Facts Table: