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WHEN A LUMEN IS NOT A LUMEN

A lumen is not a lumen when somebody intends to throw a big bunch of them out of a small reflector the size of a dime or nickel. At least it seems to be that way.

It used to be easy to tell the power of a light by the lumens figure, not anymore. You could be an experience user of lights, say a policeman that had used for years a 200 lumens Magchager and is well acquainted with its capabilities. Now he reads about this small light the size of a thumb that also outputs 200 lumens and is all excited to get the new marvel.

He does and is promptly disappointed because the small light seems to throw a good amount of light, but all close by, and is nothing that can compare with his duty Magcharger that can illuminate objects at 100 yards.

Besides emitters in the 200 lumens bracket can kill themselves with the heat that they produce when they are used in small lights with poor heat sinking. It is mostly a novelty thing and it should be used with caution. Some of them come in lights with multiple settings, and that is fine when the literature advice you to use the 200 lumens sparingly, and you follow that advice.

To illustrate the point, here are a couple of pictures of beam shots at 20 yards, you can clearly see the superiority of the Bear Cub (reflector size 2”) over the Lightstar 220, (reflector the size of a dime) even when both lights are rated at 220 lumens.

LIGHTSTAR 220 LUMENS AT 20 YARDS

BEAR CUB 220 LUMENS AT 20 YARDS

Some manufacturers wishing to quote big numbers are now putting clusters of these small reflectors on duty size flashlights. Mind you these clusters that are from three to four are still all small reflectors with limited throw.

So, somebody putting a cluster of four reflectors in a big head can claim 800 lumens, but you know better now, knowing that those 200 lumens for each reflector are not really behaving like real lumens!

Unfortunately I don’t have one of those lights to prove the point. But I can get my own cluster of lights in the 200 lumens bracket, and demonstrate by picture what can you expect.

I have here two of the Lightstar220 lumens, plus a Fenix P3D of 205 lumens and an Ultra Fire with Rebel emitter of 200 lumens, all of which together in a cluster will throw the figure of 845 lumens.

The opposite number is a Black Bear 720 lumens flashlight, a light that is 10” long and weights 24 oz. and uses a 2” reflector that can throw several hundred of yards with a strong white light.

HERE IS THE PICTURE OF THE CONTENDERS

The distance for both beam shots is in this case 35 yards to the target (The no trespassing sign tacked in the tree). The camera is 20 yards from the target.

CLUSTER OF REFLECTORS 845 LUMENS

BLACK BEAR 720 LUMENS ONE REFLECTOR 2”

Observe how the beam of the 720 lumens light travels beyond the range of the cluster lights, illuminating objects that the cluster lights are not capable of showing.
So, if you are in the market for a new light, this use of small reflectors in clusters to boost lumens figures is something you should be aware off.

Cheers
Watchmaker

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