There are a range of opinions on the subject. Today Merrill walks us though a little bit about flashlights, lumens, and cognitive dissonance. Mad Duo
(Grunts: Cognitive Dissonance)
Lumens Matter, But they Don’t
In front of me I have two different weapon lights. The power sources are exactly the same. One of them is 220 lumens and the other is a hair over 1k lumens. Which one can illuminate targets farther in the dark?
Easy question, right?
The subject of lumens, the amount of light emitted by a given source, is often contentious. Thought I’m currently a member of the quasi-cultish ‘All the Lumens’ movement, I admit to having toed a different line on a battlefield over this subject in the past. “XYZ lumens are too much” or “ABC lumens are worthless”.
We tend to focus on the raw number of lumens more than anything else about a flashlight. If you get a new light, it’s one of the first questions people ask. Why? Because it’s a quantitative measure that’s become the industry standard. Look up a flashlight and there it is (usually front and center if it’s a relatively high number, and small and in the back if it’s low). It’s stupid easy.
Understand that lumens are going to be measured in the best possible circumstances. At peak voltage with full charge batteries (actually more than likely hooked into a regulated DC source) at a distance which will record the maximum number. So undoubtedly your light won’t be as bright all the time as the advertised lumens. This really isn’t a big deal, and it’s the opposite of how the waistline is measured in your jeans from Old Navy.
And we could get into watts, lux, tint, foot-candles, artifacts, and all kinds of nerdery that will give engineers and flashlight geeks massive erections but put everyone else to sleep–so we won’t. Here are some links if you want to dive in more:
Throw, flood, hotspot, and spill matters a helluva lot more than just raw lumens.
Furthermore, each of those attributes have to work toward your intended purpose.
Like I said, lumens are easy numbers to spout off, defining the others can be a lot harder. People tend to use qualitative terms like “decent flood” or “medium hotspot”. These are completely subjective terms. While manufacturers have the ability to give you this data it will probably be worthless for most people.
Here’s an example:
“75 degree spill angle with 3,500 center lux at 1m, spot angle 30 degrees.”
If you troll around flashlight forums, there are people who conduct testing like this as well.
I used to be a shit-talker about ‘too many lumens’. I made condescending remarks to people with WMLs I considered too bright. And I was wrong.
“You planning on spotlighting deer with that?”
“Yeah, that will definitely make up for poor tactics.”
You could chalk this up to me being too old, or too old school. A decade and a half ago the best WMLs rocked 120 lumens for a whopping 20 minutes. And we were glad for it. Now it’s not impossible to run 10x that in terms of raw lumens. Light usage outside of a structure was also a huge no-no. But that really isn’t the reason, at least not entirely.
I’d seen and used lights that had so much hotspot they washed out red dot sights at closer ranges. Imagine putting your light on a limited-probability target, taking quick-but-careful aim, and….. red dot gone. Zip. Zero. In more than one instance a red dot got turned all the way up so it was a blooming mess in the dark, and the dot still wasn’t visible with the light running. There are multiple ways this issue can be fixed. First, you can simply reduce the lumens. Same reflector and lens + fewer lumens = a hot spot that isn’t as bright. Secondly, a diffuser of some kind could be used to reduce the strength of the hotspot and increase spill. A brighter RDS might do it, and you could even play Audie Murphy with irons. Or, you could just go with a different reflector and lens setup.
Instead of giving it full consideration, I went with ‘too many lumens’ answer. It was an easy-button, and though it solved that specific problem, it also decreased the abilities of the WML in other areas (namely in flood and spill). Though any of the other options would have worked, I ended up giving myself an unneeded and unwanted handicap. And it took too long to figure this out.
A Tale of Two Lights
Back to that original question. Which light could spot targets at a longer distance in the dark? In this instance they’re the same.
The 220 lumen light has a very tight hotspot with long throw, and the 1k+ lumen light is entirely flood. If you use both in a room, the 220 lumen light will actually wash out the red dot more and illuminate through spill less. That 1k+ light? No washout, and a ton of light to move around with. Despite having no discernible hotspot it can still pierce and penetrate far into dark corners, simply through the raw power it puts out.
You need enough lumens, and you probably can’t have too many lumens–but you absolutely can have them allocated incorrectly.
Don’t get sucked in. Think about what you’re using the light for. Go out and actually train with it. Admit when you’re wrong. Then try some more lights.
Mad Duo, Breach-Bang& CLEAR!
Emergency: Activate firefly, deploy green (or brown) star cluster, get your wank sock out of your ruck and stand by ’til we come get you.
About the Author: A combat veteran of the United States Marine Corps, Dave “Mad Duo Merrill” is a former urban warfare and foreign weapons instructor for Coalition fighting men. An occasional competitive shooter, he has a strange Kalashnikov fetish the rest of the minions try to ignore. Merrill, who has superb taste in hats, has been published in a number of places, the most awesome of which is, of course, here at Breach-Bang-Clear. He loves tacos, is kind of a dick and married way, way above his pay grade. You can contact him at Merrill(at)BreachBangClear.com and follow him on Instagram here (@dave_fm).