LUMENS | Language Lessons

lumens abbreviation
| February 23, 2017
Categories: Learnin'

Lumens   Abbreviation: lm “A single unit of luminous flux in the International System of Units, that is equal to the amount of light given out through one steradian by a source of one (1) candela intensity radiating equally in all directions.”

Noun, plural lu·mens, lu·mi·na [loo-muh-nuh] /ˈlu mə nə/.

Brought to you by SureFire (@surefire_llc). 

SureFire LLC lights and weapon lights.

Term: Lumens

Relates to: Light intensity  (brightness)

Category: Tactics and equipment.

Application(s) of Use: flashlights, weapon lights, light bulbs—anything that emits light

Definition: a measure of the total quantity of visible light emitted by a source


Why it Matters: There are several different ways to measure light intensity, but lumens (symbol: “lm”) are the current gold standard.

Into the Weeds: We used to roll with candlepower, once upon a time expressed as candela, which is an old and obsolete measurement which assesses the amount of light falling onto a target rather than the total amount of light emitted. The lumen equivalent of candlepower is called lux, which is used to measure luminous flux per unit area.

Pre-fluorescent and LED bulbs often stated brightness levels in watts. Though this is an extremely dated method, many LED, and CFL bulbs will list watt equivalency numbers on the box—likely so your grandparents won’t be confused.

What’s particularly noteworthy about lumens is that it’s a measurement mostly used only for frequencies the human eye can detect, rather than the entire spectrum emitted by a given light source. There are several methods for measuring lumens, but the current industry standard is to use an integration sphere, which completely diffuses any light source.


[Yes, it looks like a time machine]

The TL;DR version is this: Higher lumens just means more light from the source, not necessarily a better flashlight or light bulb.

In Summary, a lumen is just a way to measure the total light output of a given source. In and of itself it offers no other performance information. There is much, much more to assessing the efficacy of a given flashlight — how it throws the light, how the lens and/or reflector affects the light it pushes, endurance/battery life, and of course the intended use of the light vis a vis flood vs. throw, i.e. the spill and reach of the light, etc.

Question(s) for the Crowd: 

Are you a proponent of “the more, the better” on your fighting lights, or do you prefer different settings for different tasks?

Do you carry a WML off duty or daily carry?

Do you carry a handheld light every day, and if so, which one?

Read more Low Light | No Light articles:

Tactical Light After Tactical Light - Breach Bang Clear Low Light No Light WML Handheld and other tactical light articles.


⚠️ Some hyperlinks in this article may contain affiliate links. If you use them to make a purchase, we will receive a small commission at no additional cost to you.

It’s just one way to Back the Bang. #backthebang 

Declare for Morning Wood!

Come, stroll the awe-inspiring aisles of the Morningwood BazaarEarn the right to wear our sigil and speak our words.

Become a Patron!

If you wish to cite, syndicate, or curate our material, or if you’re wondering about our please be so kind as to read our Terms, Conditions, and Disclosures.
Take heed! We have advertisers, sponsors, and affiliate relationships with some of the companies you will be reading about (particularly, but not limited to, archival posts). If you purchase one of those items, we will get a small commission from the sale at no additional cost to you. A lot of work goes into Breach-Bang-Clear; by making your purchase through one of our portals you’ll be supporting our work. This will help us buy beer, bullets, and barbecue, and we won’t have to put pop-up ads and other such stupid shit into our articles to pay our expenses. 

1 Comment

  1. Nirav

    Great little guide on Lumens! Hopefully now when I mention about lumens on my website I’ll guide people to this article. 🙂


Submit a Comment

Your email address will not be published. Required fields are marked *