Police flashlight technology 101
By Ralph Mroz
The revolution in small, powerful, handheld tactical lights started by Surefire many years ago has now come to fruition. The market is exploding with lights from what seem like dozens of new manufacturers, all of them small, handheld and very bright. Today, you can buy a 60-lumen LED light at the checkout stand of your local Walgreen’s for $9.95. You intuitively know that such a cheap light isn’t up to the rigors of law enforcement work, but what’s the difference in all these new lights anyhow? What makes one better than another? Which one is right for you? In this article we’ll briefly describe the important features that differentiate one light from another.
Powerfully bright lights are now available in very small packages. (Photo courtesy of Pelican)
LED vs. incandescent
Incandescent lights are the kind that Thomas Edison invented, and that you grew up with. They cause electricity to flow through a filament (like tungsten) in a gaseous atmosphere (like Xenon or Halogen), and the glowing filament produces light. Incandescent lamps are fragile because the both the filament and the glass enclosure containing the gas can break. Thus they have to be shock-isolated if they are used in rough environments, such as attached to firearms. By contrast, LEDs (light emitting diodes) are essentially glowing pieces of a very special kind of sand. They have no easily breakable parts and are inherently shock-resistant. Incandescent technology is mature, while LED technology is gaining ground daily. Until recently, LEDs weren’t produced with good-quality, bright white output. Today they are getting more and more inexpensive, much brighter, and whiter. The bottom line is that incandescent technology is all but obsolete now unless you need IR capability, since most LEDs today don’t produce IR — however that capability is on the horizon.
Lumens, candlepower, corona, and throw
Lumens is a measure of the total light output of a lamp. Candlepower is a measure of the brightest spot in the total output. They vary independently and are not convertible to one another. The corona is the area in which light falls and is measured in degrees from the lamp; the larger the corona, the larger the area that the lamp illuminates. For law enforcement, we want a large amount of output — that is, lumens — and a pretty good size corona, because we want to see if there’s anything dangerous in as big an area as practical ay one time. We also want a uniform corona, without dark spots, and LEDs generally have an edge here. Throw denotes how distant the light remains useful for object or people identification. It can be measured in a highly technical way but the everyday, colloquial meaning above is sufficient—and probably more useful—for our purposes. Note that for a given lumen output, you generally trade throw for corona size.
While we don’t usually need diveable lights (lights that will withstand some number of meters of submersion), we do want lights that will survive a downpour or a dunking in a puddle or a river. Your light should ideally pass this test: turn the light on and throw it in a tub of water; you want to see the submerged light still working after an hour.
We drop stuff a lot, and bang it around even more. You want a light that can literally be thrown hard onto a concrete floor and keep ticking.
Powerfully bright lights are now available in very small packages — too small for my liking. I believe that the original 5-inch or so length is ergonomically optimal.
Most people agree that 60 lumens is the floor for a tactical light. That’s no problem because small lights today can easily put out 200 lumens.
I am a “traditionalist” in that I recommend a tail-cap switch that has only momentary-on capability. A side-body switch can’t be as safely manipulated during a tactical search with a gun, and a tail-cap switch that can be depressed to a constant-on position is in danger of being so depressed at the worst possible time, that is when you are searching for a bad guy and only want a blip of light, yet under the adrenaline of the moment you put the light constant-on, thus making yourself an easy target. A very few momentary/constant-on tail-cap switches are shaped so as to minimize this danger.
In the old days, you had to go with expensive CR123A lithium batteries to get “tactical” amounts of output. Today, with advances in LED technology, tactical lights can be powered by common AA (and even AAA) alkaline batteries. Also, 123A batteries have come down in price.
Strobing is becoming a common feature in tactical lights, and experience to date indicates that it is indeed useful for subject disorientation, distraction, and blinding. The controls on the light, however, have to be simple—very simple—so that you always get the output you expect: either momentary-on, constant-on, or strobe. Sometimes they are too complicated to be intuitive under stress.
Lights with low and high outputs can make a lot of sense: high for tactical work, low for routine searching for evidence or contraband. Sometimes the high output is actually too bright (too much glare) for routine searching.
Power management and run time
The longer the runtime at a given output, the better. More sophisticated lights will have power management circuitry to squeeze out those extra minutes. Also, runtimes are highly dependent on how well the light dissipates heat. The reason that one 100 lumen LED light may have a run time of one hour with two 123A batteries, and another similar light will run for two hours is usually due to how well the second light dissipates heat. In general look for runtimes at high outputs of one to two hours.
At the high end of this product class, only the very best LEDs will produce the whitest light, the longest run time, and so on. Every manufacturing cycle produces LEDs of varying quality, and those designated “Bin 1” are the best (Bin 1 LEDs may be only 1 percent of a manufacturing lot.) Manufacturers vary in quality, too; look for LEDs from Cree and LUXEON in high-end lights. Lights with less expensive LEDs will still work fine, but the difference between the light from the best LEDs and the more yellow or more blue light from less expensive LEDs is comparable to the difference between a regular duty handgun and a fine gun with extensive gunsmithing.
The weak link in most lights is the carry system. For uniformed wear most lights do come with an acceptable nylon holster, but for concealed carry, most lights also lack a well-engineered, compact, concealable carry option. After-market providers can fill this gap if a light’s pocket-clip doesn’t work for you, but since there’s no size or shape standard in tactical lights, you’ll probably have to send your light off to the holster maker.
Crenellated (scalloped) bezels are all the rage these days, but I don’t like them. If you really have to strike someone with your light, then the normal bezel edge will do the job just fine, functionally. All a crenellated bezel does is rip up someone’s face up and add to the excessive force lawsuit potential. I wish this fad would just go away.
Cops have become accustomed to rechargeable lights, but re-charging takes time and is place-specific, and rechargeable lights are inherently larger than non-rechargeable ones. With tactical lights and their batteries so small these days, many people prefer to simply carry a couple extra batteries in their gear bag, or even a second light on their person. Either option can make sense today.