PSA from Elzetta: Understanding Lumens & Tactical Flashlight Beam Patterns

First it was “Candella,” now the hot marketing and technical race is for the most “Lumens.” So just what are lumens and why are they important (or in some cases, unimportant)? How do they relate to brightness and/or intensity? What about directivity and diffusion?

Elzetta flashlights breaks it down “Barney-style” talking about how lumens is a measure of total light output and how that impacts your light selection.


Class dismissed. 

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • Steve Truffer

    Good stuff. Very Educational.

  • Fruitbat44

    Interesting little video and accompanying info graphic.

  • big daddy

    Kind of similar to the cone of fire and beaten zone.

  • Nicholas C

    I use the analogy of horse power. Just cause your honda civic has 500 HP does not make it a contender to a Ferrari. It is how the rest of the car handles that power and uses it.

    The quality of the beam is controlled by the engineering of the reflector and LED emitter. Just like a souped up 4 cyl with turbo is NOT the same as a V8 Ferrari engine. The color temp of the beam pattern is like the noise the engine makes. Have you heard the noise a Ferrari F40 makes? It is like angels are signing.

  • gunslinger

    maybe i need to come up with a new measeurement and sell it to a light company so they can have the best… out of all the competition.

  • mrsatyre

    Speaking from over a decade of technical experience in the flat panel display industry (emitted AND reflected light), I would like to point out that while his definition of lumens is correct, it’s really still not as cut and dried as he makes it out to be. Claimed lumens are based on measuring equipment and under conditions that varies tremendously from one manufacturer to the next. While there is an industry standard in how to measure them, there is no industry standard in what to make those measurements with and under what conditions. In other words, no two flashlight, flat panel TV manufacturers, etc, use the same measuring equipment and test environments—which can greatly skew the results one way or the next. For example, how far away from the light is the measuring equipment? what is the color of the paint on the walls in the room which will reflect that light and subtly affect the sensor’s readings? etc. Reporting measured lumens is not a scientific process, because the testing between brand A and brand B aren’t ever done under identical laboratory conditions.