Well, at least everything I’ve come to believe about them. In regards to civilian defensive firearms and self-defense.
Do you need a light at all?
For typical civilian defensive firearms uses, probably not. Tom Givens, the man with the data on such things, explains why here. Essentially, bad people attack good people in low light, but in enough light that 1) they can see what they are doing, and 2) you can see them and feel sufficiently threatened. This is because most violent attacks are co-incident with robbery. I hear the whining…but data. And logic.
That said, I do believe in carrying a light. Shined in the face of an assailant or unknown contact it’s a low-level force tool, and it can illuminate unknown areas (think a dark parking lot, or unseen hands).
I really don’t like lights on handguns. I used to have one on my service pistol when I was a cop, but we’re talking civilian self-defense here. (Handgun-mounted lights have the same advantages and disadvantages regardless of who is using them, but cops are often offensive and pro-active, in comparison to the mostly defensive and reactive use of weapons by civilians, and the trade-offs are thus weighted differently.)
1) There are two methods of activating a handgun-mounted light, and they both suck. Any operation by a finger either compromises your grip or (in some really faulty designs) causes your trigger finger to risk hitting the trigger. And designs that operate off of grip pressure become death traps when your grip, under stress, squeezes the button unintentionally and gives you away. Besides, you’ve spent your entire shooting career learning how to tightly hold the gun…and now you have to delicately modulate the pressure??? Under stress???
2) Rail-mounted lights cause you to violate Rule 2. Yes, academic theory says you can keep the gun lowered and search or ID threats with the periphery of the beam…but seriously??? And again: under stress??? This is a lifetime of free room and board in the making. We all get stupid under stress!
3) Least important, but a factor: they require funky holsters and make concealability more difficult.
What I prefer is a hand held light, with a nice ergonomic length of five or so inches, held to the neck or cheek, and operating the handgun one-handed with the strong hand. By far and away most defensive gun uses are short-range affairs, and you should be reasonably competent with your gun — shot one-handed — at short distances. If I really need to shoot two-handed with a hand-held light (very unlikely), there are a number of well-known techniques for so doing; pick the one that is most comfortable for you and retain some competence with it.
Of course the advantage of handgun-mounted lights is that two-handed shooting is easier (and more accurate). I can only see the trade-off of using a rail-mounted light if you have good reason to believe that your defensive handgun use is likely to be (not might be) at a long distance — quite a bit longer that Tom Givens’ data indicates is likely. In which case you might consider schlepping a long gun instead.
As I’ve said many times before, every defensive long gun needs an attached white light, one that can be easily and independently operated with the support hand. 1) There is no other option for a light — you can’t hold one in your off hand and run the gun. 2) Attached lights are tactically free – you don’t trade-off any other capability by having one: they don’t add significant weight, don’t affect function, and they don’t compromise carrayability. 3) Long gun engagements tend to be longer range, where you may well need the vision enhancement.
Now, employing a light on a long gun forces you to violate Rule 2, but there’s no other option except to not use a light.
A tactical light is not a utility light, and should not be used as such. A small utility light can be carried on a key chain or in a pocket, but a tactical light has only two purposes: searching and target identification, and it should be dedicated to those tasks.
A tactical light should have only one switch function: momentary-on, because that’s the only mode in which you can search and ID without yourself drawing fire. And it should be located on the tail cap. Most tail-cap switches are a combination momentary/constant-on switch, and these are suicide switches. Under the strength and clumsiness of stress you severely risk depressing the switch to constant-on when you only meant to blip it…and now you are an easy target for incoming fire. These two-stage switches are so common only because most light buyers simply do not understand the issue, and you know, more modes have to be better!
Even worse are the lights with multiple modes: constant-on, momentary-on, low output, medium output, high output, disco (strobe), fade, and reading your astrological chart. 1) It takes a user manual to figure out how to use them. 2) They always get into a messed up state, just when you need them. 3) They are too complicated to operate under stress. 4) You put them into the wrong state when you try and operate them under stress. 5) The only useful state is momentary-on anyway. These lights are sold mostly to nerds who have never actually used a light in, at a minimum, a realistic scenario. Consequently they sell well.
The light should be ergonomic: approximately five inches long and 3/4 to 1-inch thick. Any shorter and it becomes clumsy to operate, especially under stress, which means that it’s unreliable under stress.
Surefire got it right out of the chute, what – 25 years ago?, with the 6P. The more ergonomic 6Z shortly followed, although I preferred the less expensive polymer-body Nitrolon versions because I live where we get real (that is, damn cold) weather.
Lumens, and the other geeky stuff
The introduction of the Surefire 6P with an amazing 60 lumens(!) was like entering the jet age from the horse-and-buggy days of the old Maglites (or Kel-Lites, which was before even my time). No one in the tactical community complained about too little light then, and the whole discipline of tactical while light use (with handguns) was born.
60 lumens still gets the job done, most of the time.
Now with 1000 lumens available in reasonable quality packages for cheap, the temptation is to get seriously geeky about lumens, candlepower (it’s making a comeback!), coronas, throw, white color, and a dozen more technical characteristics of small, handheld LED lights. Places like candlepower forums are a great resource if you love the techy stuff, but really, it mostly doesn’t matter these days.
Color (that is, how “white” the white light is) certainly doesn’t matter. Nothing that you will ever have to see or identify, even at great speed, will suffer from a slight blue (or whatever) tint to a light that’s, for all intents and purposes, white.
Indoors, beam concentration doesn’t matter, because, and this is the overriding factor at work in all of this: we gotta lotta lumens these days. Lumens to excess in fact, and that makes a lot of things that used to matter irrelevant now. It’s like MIPS; do you know how many MIPS your PC has? Probably not because they are cheap and abundant these days, and all PCs have them in excess for most tasks. Twenty five years ago, if you knew anything about computers, you certainly knew the MIPS of your machine because it mattered for ordinary tasks. Progress.
Outdoors, at long distances, beam concentration can matter.
The great debate now is the question: Can you have too many lumens? One side says that you can easily blind yourself indoors with too much light, especially in rooms with reflective surfaces and white walls. The other side claims that you want as much light as possible to see into every dark nook. I’m kinda in the former camp, but not dogmatically. It is certainly true that, say, a million lumens would blind you, but handheld lights these days are in the range of, mo’ less, 200 to 1500 lumens. In this range what constitutes a blinding amount of light will vary by person, and for each person, by age. I find 200 lumens more than sufficient to see anything, anywhere, in any house I’ve been in, and past 400 or so it starts to feel too bright. YMMV.
Three pieces of context: 1) any reasonable amount of light will degrade your night vision for a time, and the more light the longer the degradation, 2) you only need a couple lumens to see a remarkable amount at room distances, and 3) outdoors you want all the lumens you can get.
Quality & ruggedness
Here’s where I stop being a Luddite curmudgeon. These are things worth caring about and spending money on. 1) Your light has to work when it has to work. 2) Shit happens at the worst times and you want your light to take a good drop — or follow you down when you fall — onto a hard surface and keep going.