Informative WML video

[Archer1440]

As this covers handheld, pistol, and rifle mounted WML’s, there’s no best place to put it, but I found it informative and interesting. Hope some of you do as well.

https://www.youtube.com/watch?v=gJD44ZOKyLM

[NH Shooter]

Good find, thanks for sharing!

As many of you may know, this has been an intense focus of study of mine for a long time. I'd like to offer some commentary on this video, which I think is very much worth watching.

Candela-to-Lumen Ratio

This video does a great job of illustrating the beam patterns of various lights, and by providing both the lumen and candela rating of each light, we can begin to see that considering both of these ratings together offers clues on what the beam pattern might look like. One way to estimate what the beam might look like is to determine the ratio of candela to lumens as rated by the manufacturer.

A few examples of lights I personally own;

The Malkoff 91B drop-in is rated at 8,000 candela and 1,000 lumens for a 8/1 ratio. This drop-in is best characterized as a "flood beam" pattern with a broad, evenly illuminated beam but with minimal reach.

The Malkoff 91T drop-in is rated at 19,000 candela and 750 lumens for a 25/1 ratio. This drop-in focuses more of the lumens into the center of the beam resulting in over double the reach (brightness) of the 91B. It maintains plenty of lumens in the spill and based on my own observations, more than enough to see and discern with some detail anything that is covered by the spill (which is also wider than the 91B).

The Malkoff E2XTD is rated at 70,000 candela and 650 lumens for a over a 100/1 ratio. This is an extremely tightly focused beam that can easily illuminate in detail a target at 100 yards, but has minimal spill. This is the head I use for my "Light Saber" which I have set up strictly as a PD light to deprive an assailant of their vision in a low-light environment;




Understanding Lumens vs. Candela

Lumens is the total "volume" of photons a light emits, regardless of direction (beam pattern). Candela (equal to lux when both are measured at one meter) is the brightness of the light as a point source. In the illustration below, luminous flux = lumens, luminous intensity = candela and illuminance = lux;




When the measurements are both taken at one meter (as is the practice for flashlight specification), lux and candela calculate to the same number.

Understanding Brightness

As stated above, brightness is defined by luminous intensity (candela or lux). Thus how "bright" a light appears is determined by its candela or lux rating, not by the lumen rating. In the Malkoff examples above, even though the M91B has about 50% more lumens, the E2XTD appears nearly 10 times brighter to a person observing the light from a distance (as a point source).

So in conclusion to this post, one must consider both lumens and candela/lux to understand how a light will perform under the conditions (and purposes) for which the light is intended to be used.