I recently went looking for a basic flashlight to replace one that had rusted out; no big deal. What I needed was nothing special, just a small one which used two or three AA or AAA batteries and was lightweight so it would be easy to carry. This would be simple: go to a store that had a wide selection of sizes and form factor, do some browsing, and make a selection. I assumed that all flashlights would now be LED units, not incandescent.

That trip was a revelation. Roughly one-third of the lights were LED, one-third were halogen (a special type of incandescent), and one-third were incandescent. I thought that the well-known, much-greater efficiency of LEDs, plus the fact that flashlights are inherently power limited by their battery capacity, would have overwhelmed the non-LED types by now.

So I started thinking, why do they still have non-LED flashlights? It might be that the vendors of these non-LED units have very low-cost production which is fully amortized, given the many years they have been making them. Or perhaps the cost differential between the LED and non-LED units at a given brightness level is still substantial for other reasons that I can't see. Perhaps some customers prefer the warmth of the incandescent glow.

From my perspective, the traditional incandescent bulb was reliable but they do eventually burn out (though some flashlights have a spare-bulb holder built into their base). They also survive shock and vibration amazingly well, but I have had problems with corrosion at the overall bulb into socket pairing which, in theory, would not have happened in an LED unit where the connection is soldered.

As an engineer, I did the obvious thing when looking at this array of flashlights: I tried to find and compare otherwise equivalent units with different light sources, but I found there weren’t “apples to apples” match-ups. For example, I hoped to find an LED unit and an incandescent unit with the same output, to see the difference in price and run time, but such an obvious match wasn’t there.

However, I did notice that many of the flashlight packages did have some ANSI specifications and brief definitions of each on the back of the package – in this case, identified as ANSI FL 1 (2009) – which did allow for fair comparison. Three parameters were called out: lumens, run time with batteries provided, and useful distance. Of course, this led me to the engineer's next question: under what specific test conditions are these standards defined?

An online search quickly brought answers, via a clear and useful exposition: “Understanding the ANSI FL1” from PLATO, the Portable Lights American Trade Organization (another group that's new to me) and the excellent PowerPoint presentation “Streamlight: ANSI/NEMA FL1 Standard.” The first one summarized ANSI FL 1 (co-authored by NEMA) is very useful and shows a path for comparison of different flashlights, and helped me make a decision; the second and longer one explained in plain terms with diagrams how the various tests are set up and provides more definitions (see image below). Summaries from other sources were also available online, of course.

I still don’t know why they are selling incandescent/non-LED flashlights, but at least I have learned about the ANSI/NEMA standard for these essential and often taken-for-granted consumer devices. So I'll call that win on my personal list of worthwhile but unexpected learning experiences that I obtained without having to go on a painful path to get there.

What's your view on why there are still non-LED flashlights? Can you recall situations where you inadvertently learned something useful looking while for the answer to a different question?

Bill Schweber is an EE who has written three textbooks, hundreds of technical articles, opinion columns, and product features.

“It's because optoelectronics engineers buy them in huge quantities for use as cheap portable IR sources for simple testing.”

“One disadvantage I have found with LED flashlights is that the beam is usually very narrow. Useful if you're trying to illuminate something specific but not if you are trying to scan an area looking for something. Some time ago I lost my car keys while

“David, I think your wondering as to “why they don't use tagged, soldered batteries” is answered by your previous statement “eventually the rechargeables would fail or lose capacity, and 99% of the great unwashed would then just chuck them out.”nAlso,

“Great article Bill. My flashlight question is why are there so many – most – flashlights that require shacking to get them to turn on? The soldered LED eliminates two potential “contact connections.” Even the good quality flashlights have this “feat

“People probably still buy old-style flashlights for the same reason they still buy analog multimeters”

“As a long time user of the venerable AA Minimag flashlight, I can easily compare the old Halogen versiu00f3n to the newer “LED conversiu00f3n” (made by Nite Ize). The failure with the LED versiu00f3n is that it cannot compete with the Halogen bulb A

“Bill…. maybe true… but in the solar garden lights the rechargeables are needed, so why not connect them in the most reliable way possible? To sell more of them? I make a point of not re-buying types that let me down. Re flashlights (sorry, I'm Bri

“They can make LED light sources just as “adjustable” but requires more optical elements. Actual lenses over just moving the incandescent bulb in relation to the focus of a reflector. AND be sure LED versions are out there, just cost more than most are

“LOL you joke BUT…nnNorthern cities when first converting to LED traffic lights had an issue when the snows came (obviously doing the incandescent switch in the warmer months. When show accumulated on the fronts of the traffic lights… because the LE

“Cost!nnMy 2xC cell Maglight flashlight and my LED flashlight are about the same in lumens. The Maglight cost me about $30 the LED $165. The LED is non adjustable which really sucks. The battery life is LESS for the LED. The advantage of the LED is s

“Where LED flashlights do shine is headlamps. I will not use an incandescent headlamp ever again.”

“If you shine a flashlight anywhere near someone's eyes, the LED is harsh and painful. When I teach kids about the phases of the Moon I need a bright incandescent flashlight to represent the Sun, otherwise the person portraying the Moon gets an uncomforta

“A couple times a day, I take a break from what I “should” be doing to read something of interest and follow links to answer questions that have come up. I learn things all the time, that help me make sense of the world. At some points in my career, I ha

“I've found LED flashlights to be superior to normal Maglights and other non LED lights. Problem is there are lots of poorly designed LED flashlights out there and a bunch of expensive collector FL's too. I've gone through a bunch of them over the years.

“Then, would you be so kind to tell us some brands or models, so that we could try to obtain a well designed unit, please?nnAs far as I have tried (I live in Mexico City, and in my travels to Houston TX have not found an acceptable unit in the stores the

“Battery contacts are a source of increased electrical resistance, no doubt about that. There is a company called “CAIG Labs” that even produced a contact enhancing liquid which purpose was to extract more light from a flashlight by reducing resistance.

“For your “old” favorite Maglite torch you can get LED bulbs, same size as the original tungsten filament bulb, and has DC to DC? (LED drive) converter built into the base ! Search eBay for example…”

“LED headlights are harsh on the eyes if you're the oncoming driver. Also, so many vehicles are higher than they used to be, putting headings even more in oncoming drivers' eyes.”

“As far as the Mag-lite flashlights go, the incandescent flashlights (starting with the 2D cell at 27 lumen) are probably still being sold because idiots like me are still buying them! I have had Mag-lites for about 30 years now, just bought another 2D ce

“I'm using Pilot Frixion erasable coloured pens for technical drawings, and I'd love to find an incandescent flashlight to heat up the paper to 60 degC where I want to erase the ink. (Rubbing the paper with the rubber eraser damages the surface.) A double

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