BeigeJournal

Well, it’s nearly Thanksgiving here in the USA and someone in a lab near my office at the Medical College has a radio cranked up playing “I’m Dreaming of A White Christmas.” At least it is late November. The Christmas displays went up in the stores before Halloween. I can hardly wait to hear “Jingle Bell Rock” a few thousand times next month. I do highly recomend Tom Flynn’s The Trouble With Christmas.

In the Dan’s Data tradition, but at a smaller scale, here is my LED flashlight review.

Original CMG Infinity

I own an old-style CMG Infinity single-AA powered single-LED light. The new style is brighter. Though not very bright it is bright enough to be very useful. It is great for use in a tent, for just a bit of light to find things by. It is a small cylindrical object, which you have to hold somehow. Headlights tend to be easier to use for many applications, so I purchased a head strap for it, but it is much harder to aim than a proper headlamp. The AA-size cell rattles a bit when the light is turned off. Battery life is excellent, as you’d expect from a low power light.

Black Diamond Ion

The Black Diamond Ion is a very tiny headlamp with twin LEDs. It is powered by a 6-volt silver-oxide battery that you are probably not going to find easily. REI sells them for $5. Claimed battery life is under two hours. I received mine as a gift and though I carry it with me always I’m still on the original battery after a year. It gets very intermittent use but it is very handy to have around. It is quite bright for its size, roughly the equal of the Princeton Tec Matrix. It has a single strap and the angle can be adjusted up and down. I was skeptical of the tiny, expensive, not-readily-available battery, but the small size is very convenient and the battery life with intermittent—a minute here, a few seconds there—use is quite good. It is probably not a good choice for extensive use as opposed to extensive keeping with you just in case.

Princeton Tec Matrix

The 2 AA-cell powered Princeton Tec Matrix headlamp (not to be confused with the new and much brighter Matrix 2) is my favorite. One strap goes around your head, another over, with the battery compartment and lamp assembly all one piece on the front, with the angle adjustable up and down. It has three white LEDs powered through a DC-DC converter that provides stable power for the LEDs whether supplied by fresh lithium cells (1.7V each) or nearly dead alkalines down below one volt per cell. You can swap back and forth with no visible difference in the light output. There are those who claim that declining output as the battery dies is a useful indicator of battery life. The people claiming this are too cheap to do it right. Since humans have very poor ability to determine absolute light intensity, you can only really tell if your light is getting dim if either it is so dim that you finally realize that you can’t see a thing or else if you swap in fresh batteries and notice the sudden increase in light output. That is not a convenient battery charge-state indicator in my book. I’d much rather have steady, full-output light until the cells are truly dead. Princeton Tec claims 40 hours on alkaline cells and over 100 hours on lithium cells. The availability of lithium AA cells is an advantage for AA-powered lamps, particularly for cold-weather use. After loading two alkaline cells that I pulled out of the trash (the incandescent lamp they were powering was getting quite dim), I spent two days trying to run them down. I got around 20 hours of service. Out of dead batteries. The end of life behavior is interesting: fading rapidly to no light once the input voltage drops too far, then, after the cells recover a bit, turning back on and running at full output again for a while until again the voltage drops too far, and the cycle repeats.

The lamp also comes with an incandescent module that can be swapped in for times when you need brighter light and much shorter battery life. I suppose uses for this can be imagined, since the reflector and bulb assembly is much smaller and lighter than a complete second headlamp, but it is also a lot more effort to exchange parts than to just use a second lamp, or to turn on the incandescent bulb in those lamps with both incandescent and LED sources built in.

This is not an especially bright light, with three LEDs apparently driven gently. It is suitable for reading, though possibly just a bit bright for that. A bit of diffusing material held over the light with a rubber band helps even out the light and dim it slightly. It is quite good for close-up work. I find it useful even in my brightly-lit apartment as supplemental light for fine work that can’t be taken to the workbench. It is bright enough for walking outdoors at night. What I wanted when I bought this light was something I could really put a lot of hours on without going through lots of fiddly little hard-to-find expensive batteries. I have found it. This is a light you can strap on, turn on, and leave on, without worrying about the battery. You have days of non-stop use right there on your forehead.