(The opinions contained are my own and not necessarily those of the Department of Physics at Weber State University or of the Weber County Sheriff’s Search and Rescue team. I maintain this web site, so that is why I located it here.)

LRI Photon Fusion

Petzl Tikka

Black Diamond Moonlight

Homemade 4-LED retrofit to the Petzl Zoom (A "how to" page is under construction)

LRI Photon Fusion

I have a PhD in experimental physics and teach upper level optics and electronics courses. I have been involved in outdoor activities for nearly 40 years and have been on a Search and Rescue team for over 10 years. I have spent many hours experimenting with homemade LED headlamps and with LEDs on an electronics prototyping board. I’ve tried various combinations and quantities of LEDs, alignment schemes, brightness control modifications, transistorized current control, etc. I have also compared side-by-side LED lamps with halogen and standard light bulbs. I’ve experimented with skiing, hiking, climbing, and mountaineering with LED and regular headlamps. I’ve also been on search and rescue missions were some team members had LED headlamps and some had regular headlamps.

Observation #1: This report is out of date the moment I hit the save button. It is much like buying a computer, you can buy the fanciest LED on the market and next week there will be a better one. The designers of LED lamps are rapidly improving their products. They are creating brighter LEDs that use exactly the same amount of electrical current as the earlier (dimmer) models and often for exactly the same price. That means that you will get more light for the same battery lifetime with each new improvement in LED efficiency.

Observation #2: All LED "bulbs" are not the same. Some LED manufacturers have better lamp to lamp consistency. There are two primary reasons for this. The way LEDs focus the light is to have the end of the plastic LED body to be formed into a focusing lens. If the location of the light source (the tiny LED semiconductor and fluorescent assembly) is not at exactly the right position then the lens will not cast a clean, well-focused, beam. If the quality of the plastic and the molding process is not high enough then the lens will not perform well. The result is that some lamps have rings and bright spots in the beam and some have a very uniform beam.

Observation #3: No matter how many LEDs you have, the "throw" of the light (the distance that you can illuminate) does not compare well with any standard or halogen lamp system. Especially lamps that can be focused to change the illumination spot size. I can easily cast a spot on a rock wall 75+ meters away with a halogen lamp in a Petzl Zoom. LED lamps will illuminate objects 15 to 20 meters away, but adding more LEDs (I tried as many as ten) does not significantly effect the throw of the lamp. I was able to notice that distant (50+ meters away) rock or canyon walls were being illuminated by the LEDs but the lighting was not adequate for SAR work or detecting anything that would be at all subtle. More LEDs will make the ground in front of you brighter, but it will also seriously impact battery lifetime. Each LED typically draws about 20 milliamps. Doubling the number of LEDs will roughly half the battery lifetime. (At some point the battery lifetime is reduced even faster because battery performance drops as you draw more current.) In the end, I’ve decided that four to six LEDs is about optimal.

Observation #4: For night hiking, climbing, skiing, or mountaineering the LED headlamps worked very well. On one particular winter SAR mission (rescuing out-of-bounds skiers) my tired batteries (brand new batteries with several hours of use on this mission) in my standard headlamp were making it difficult to ski down the mountain. Meanwhile those team members with the three LED Petzl Tikka headlamps were having no problems skiing at reasonably high speed down the dark runs of the ski area. On a climb of Mount Rainier my (two different) LED headlamps were plenty bright for moving around camp, messing with gear, and for climbing. At the City of Rocks I could easily see far enough ahead for route finding and anticipating where to set pro for climbing after dark. In fact, I found the LED headlamps to be superior to standard lamps because the light was more uniform and less bright causing less dark adaption and contrast problems. I could look down at my feet and then immediately up ahead along the route and not have brightness or glare problems.

Observation #5: The LED illumination pattern is fairly important. In other words, how you point multiple LEDs makes a big difference in the quality of the light. LEDs typically have a 20 degree spread to the light beam. If all the LEDs are pointed in the same direction you get a brighter spot but you loose peripheral vision. If you point the LEDs slightly away from each other then you get nice broad illumination but it isn’t particularly bright.

Observation #6: Color varies substantially from one type of light source to the next. The standard light bulbs have a distinctly yellow-orange cast. The halogens are fairly white. And the LEDs vary from brand to brand with many of the LEDs having a distinctively blueish-white light. For most things this probably doesn’t matter, but for SAR work and patient evaluation you want to have the light as white as possible. I have made spectral scans of the various light sources in my laboratory and the results matched these observations. My very casual observation is that the newer LEDs seem to be getting better at providing a well balanced white light.

Observation #7: All headlamps will get dimmer as the batteries are "used up." I found that the LED lamps have a more consistent drop off of light then filament bulbs do. In particular, filament bulbs seem to stay fairly bright then suddenly drop off in brightness as the batteries become depleted. What manufacturer’s claim and what you observe for battery lifetime may not agree. Depending on what you are using the light for, you may be able to get adequate light for longer then claimed. The LRI Photon Fusion uses an electronic circuit chip to reduce this effect, however when the light does fail it fails fast. 

This was the most versatile headlamp with the most features. It was my personal favorite. It was also the heaviest headlamp (but comparable in weight to the homemade retrofit of a Petzl as described below). The headlamp that I was testing was a pre-production prototype. There were several manufacturing flaws and features that I was told have since been changed. Each of the concerns that I had were already addressed and fixed in the newer versions by the time I returned the unit. I have now reviewed the full production run model that my wife just bought and all the flaws have been fixed.

Features that I liked:

The six LEDs where very carefully aimed. Four of them are aligned to create a bright central spot while the two side LEDs are pointed slightly to the side (i.e., horizontally offset). This gave me adequate central illumination while also providing a pleasant amount of light for peripheral vision. I did not have the sense of tunnel vision that some of the other LED headlamps gave me.

The lamp has seven different modes of operation: full on, medium, dim, fast strobe, medium strobe, slow strobe, and auto-off/power gauge. The only real reason that I can see for the strobe feature is emergency signaling. I had no need for this feature and just cycled past it each time I changed modes. I might try the strobe for SAR use someday though.

There is also a "hyperbright" mode that is exactly that. The hyperbright mode is always instantly accessible at the single press of a button. In this mode you will run down the batteries much faster, but when you really want the light it is there.

Because of the circuitry, the lamps' output is controlled in such a way as to maintain a uniform light output followed by a sudden drop in brightness. This is compared to the slow and continuous drop in light output of the other lamps I experimented with. This makes the power gauge feature useful because it tells you how much life is left to your batteries.

The power button has a really cool feature in that it is faintly illuminated. It has a highly efficient phosphorescent chemical inside it that will cause it to glow without battery power for many hours. This makes it easier to locate in a dark tent and very easy to locate the on-off switch in the dark.

You can easily take the lamp head off and reconfigure it to act like a standard hand-held flashlight. I did not have much need for this feature, but I can see how it might be useful in some cases.

It is made out of bomb-proof material. While I don’t suggest that you try, you could probably drive your car over this headlamp then pick it up and use it.

Things I noticed:

The double-A batteries are probably overkill. I used it for two weeks of camping and on a climb of Mt. Rainier and never changed the batteries. Although triple-A batteries would make it more compact, it would have little impact because the design is such that the battery housing is also the base (and flashlight handle in that mode) of the unit. The only real advantage would be the small weight difference between the two battery types.

Things I didn’t like:

I’d have less strobe options if it was my design. But, in practice this is not a big deal.

The balance was slightly front heavy since the entire headlamp was mounted at the front of the straps. On the other hand this means that there are no wires running around the straps between a front lamp and back battery pack. Anyway, the balance issue is quite minor and the strap and headlamp system was comfortable and well designed. On the whole, I really liked this headlamp.

Petzl Tikka

Several members of our Search and Rescue unit own the Tikka headlamp and love it. They have used this headlamp on climbs of the Grand Teton and are completely happy with it.

Things I liked:

It is extremely light weight.

It is a very "clean" design with nothing to snag on anything. Then again, I’ve never had a headlamp snag on anything anyway.

Things I noticed:

There is no way to point the light in any particular (up-down) direction. On the other hand it seems to be designed to point in pretty much the direction I wanted anyway. Fine adjustment was fairly easy by simply sliding it further up or down on your forehead. I did not try this headlamp with a helmet on.

Things I didn’t like:

There is no way to control the brightness. Not usually a problem, but brightness control was a nice feature of the Photon Fusion.

The three LEDs generally provide adequate lighting, but the four and six LED headlamps gave just enough extra light to be really nice.

Things I liked:

As with the Tikka, the Moonlight was remarkably lightweight.

The balance was nice and the rear battery pack was plenty easy to operate.

You could direct the beam up and down as needed.

I really prefer the additional light you get with four LEDs instead of three.

Things I noticed:

It has a unique "look" to it. Sort of a Star Wars droid look. (I thought it was kinda cool looking actually.)

Things I didn’t like:

There is no brightness adjustment.

The unit I tried did not have well protected or solidly mounted LEDs. The result was that the illumination spot was sort of a vertical oval shape. I found that by using my fingernail to snag the LEDs I could bend the mounting leads around a bit to redirect the light and modify the spot size and shape. I found that I preferred having all four LEDs pointing forward into one spot. Although by shoving them around a bit you could get whatever pattern you wanted.

I have to wonder how well this headlamp would hold up if you took a major face plant while skiing at night. It has a fragile look to it, although Black Diamond claims that it is fairly rugged.

My homemade 4-LED retrofit to the Petzl Zoom (A "how to" page with assembly pictures can be found here.)

I made a four LED lamp that would fit into the Petzl Zoom. Since the Zoom is a 4.5 volt system it is especially easy to adapt to a white LED system. I was able to make it so that I could have both the halogen lamp and the LED lamp available for interchange as needed. Inside the back of the lamp housing is a spare bulb clip that will hold either bulb at the ready.

Things I liked:

I liked the price, since I own a Petzl Zoom already, the price of the components was less then $15. It takes me less than an hour to make one.

The battery life is awesome. Using the Petzl AAA battery adapter I tried to run it down while camping and really couldn’t do it with normal use in a week’s camping trip. If you used the large flat 4.5 volt battery it would have enough power to run for ages under normal use. I got tired of waiting for it to get dim so I took used AA non-rechargeable alkaline batteries that had been recharged anyway, turned it on, and stuck it in my kitchen freezer. Each day I’d check it and after 54 hours of being continuously on at sub-freezing temperatures with crummy batteries it was still bright enough to walk down a rocky dirt trail. The brightness had dropped enough to be annoying but was still plenty usable.

Things I noticed:

If you tried to point the LEDs outward slightly (larger, but dimmer spot size) it would not fit into the bulb opening in the Petzl reflector without carving out the hole in the reflector a bit. Ultimately, I decided that I preferred the more concentrated spot anyway.

While you can easily build this yourself (look for a future web page on the process) you can also buy two and three LED replacement lamps that are interchangeable with the 4.5 volt Petzl lamp.

Things I didn’t like:

If you don’t buy a bunch of LEDs or if you can’t get them locally then the shipping costs become a substantial fraction of the price.

You are limited to a maximum of four LEDs unless you really hack out the back of the reflector. (If you really wanted to, you could chop out the back of the reflector and mount twenty or more LEDs back there and get a lot of light. I never tried this.)

What would my ideal headlamp have? It would be like the Petzl Duo but with one side being a four or six LED lamp and the other side being a focusing halogen bulb system. Thus, you could really cast a long distance spot of light when you need it but conserve battery power when you don’t. (Note that the Duo is a 6 volt system and would require additional, but easy, modifications to run my homemade LED lamp.)

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