Lumen vs Lux. Which wins?

saabluster

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I wanted to fill you all in on some testing I have been doing with the DEFT-X. A CPFer had asked me about the ability of the DEFT-X to "blind"* someone vs other lights. In particular vs a high lumen light. So Lumen vs Lux. Which wins?

For the most part this is just a regurgitation of my emails to him. I wanted to go ahead and get this on CPF while I had my thoughts in print and before I forgot.


"I used a TK70 I modified with dedomed XML2 U2 against the DEFT-X. The TK70 I have measured in at 203Kcd. It is probably putting out around 3000 lumens. The result of the test was unequivocally in favor of the DEFT-X. I shined both beams down my alleyway and then walked out a distance and looked back. The TK70 beam although bright was not that hard to look at. I certainly had perfect view of all the area in between me and the lights as well. Looking into the beam of the DEFT-X however was wholly different. It caused me to lose almost all visibility of the space in between me and the lights. All I could see was streaks of intense light all across my vision. Those streaks mask anything you might have seen otherwise but is also aided by the fact that the pupil is constricting like mad and thereby reduces what one would otherwise be able to see. I can't say it creates a complete "blindness" effect but it is pretty close. So the result is that if you want to incapacitate someone with light there is nothing LED based that can beat the DEFT-X. I'd imagine the next best thing would be the TN31mb as it has the second best intensity in the industry. "

After this test he asked for more info on the DEFT-X vs the TN31mb. So I decided to test all three.

"Well I just tested all three. The results were about what you'd expect. And yes the DEFT-X is significantly more potent of a "blinder" than even the TN31mb. I had somewhat of an epiphany as to one of the side benefits to the DEFT-X in this particular arena. The blinding factor is but one angle in its effectiveness. The lack of spill means that there is no light hitting the ground in front of the target. With a normal reflector light you are in a sense helping them out by lighting their way at the same time you are trying to blind them. No such luck with the DEFT-X. This makes it even more useful than even its lofty numbers would suggest. I'm glad you asked me to do this test as I have learned a little bit more. Will help when I go to talk to my local police about my lights. I also made a note to test out whether the narrow beam of the DEFT-X is a significant detractor in comparison with the reflector lights. What I found, somewhat to my surprise, is that the extra beam width with a reflector light does not help. For two reasons.

You can't have your cake and eat it too. The wider the beam the less intense it is. Meaning if you do get a beam that is sufficiently large enough to be able to just aim in an area the blinding ability of the light will be massively reduced. And maybe to the point of complete ineffectiveness. The thing about a reflector light as well that is somewhat deceiving is that the corona makes the beam seem bigger and while it can add significantly to what one can see down beam that portion of the beam drops off in intensity drastically from the hotspot. You can try this on yourself. The blindability once you leave the hotspot is next to nothing even if you do still have light shining on you. So what this means is that if you do have a reflector light with any serious amount of ability to "blind" it too will be difficult to hold directly on a person's face.

The second thing is that the sharp cutoff of the DEFT-X means that either there is massive amounts of light entering the eyes or nothing at all. This is actually good. Even if you can only hit the eyes in bursts, maybe from them trying to avoid it, what they do see in the off period is not causing their pupil to constrict. This means the times the light does hit their eyes it will seem even more intense. The eye simply doesn't have time enough to adjust when experiencing these bursts. That is one of the reasons why strobe is effective for this type of scenario.

Of course one can never anticipate all the possible scenarios and certain scenarios may favor other types of lights. Hard to say without real life experience. What I have seen in my limited testing is the DEFT-X blowing away all the others. Even my own TN31mb. I hope this helps. -Michael "


I mentioned somewhat about the DEFT-X's ability to hold people at bay, for instance in LEO work, but I don't think enough people realize just how serious I was when I said this. This light is on another level altogether in this respect. Those who have their lights already can go test this themselves.

*By "blind" I am referring merely to a light's ability to make it so difficult to look into that you simply must turn away due to the intensity and/or the effect created in the eye by the distracting and masking streaks that run across your vision when viewing the high intensity light. It is highly unlikely that even a light as intense as the DEFT-X would cause blindness unless sustained and prolonged exposure were to happen. I tested this all on myself. :)
 
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LuxLuthor

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Good information. The only fine point is to not classify the less blinding lights based upon their having a reflector. An example of that is the MaxaBeam, which in fact uses a highly developed, polished reflector to give an intensely focussed beam that would blind much more dramatically than the Deft-X. The defining issue is the magnitude of the throw painting the target. The sun has a nearly infinite spill, lighting every blade of grass as far as the eye can see, and giving plenty of warning that something uber bright is up there...but for those unlucky souls who stare directly at the sun (like a powerful laser), they could sustain permanent retinal damage.

In any case, there is no question about what you are reporting on regarding the blinding effect of the Deft-X. I don't think anything compares in a handheld.
 

saabluster

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Good information. The only fine point is to not classify the less blinding lights based upon their having a reflector. An example of that is the MaxaBeam, which in fact uses a highly developed, polished reflector to give an intensely focussed beam that would blind much more dramatically than the Deft-X. The defining issue is the magnitude of the throw painting the target. The sun has a nearly infinite spill, lighting every blade of grass as far as the eye can see, and giving plenty of warning that something uber bright is up there...but for those unlucky souls who stare directly at the sun (like a powerful laser), they could sustain permanent retinal damage.

In any case, there is no question about what you are reporting on regarding the blinding effect of the Deft-X. I don't think anything compares in a handheld.

You are right about not classifying all reflectors as "non blinding". That wasn't really my intent but I could see how some might take it that way. It is however down to the two things I mentioned. The main one being beam intensity. This was originally an email exchange and I did not vet it like I normally do if I am posting here on CPF. I just haven't had the time lately for in depth technical conversations like I have done in the past. Just been slaving away for you all. :)

Anyway I think your analogy with the sun helps make my point quite clear about the benefits of the DEFT-X(or any aspheric light) as compared to reflector lights. The beam intensity is but one part of the equation when it comes to being able to use a light to hold someone at bay. Even on the sunniest of days I cannot ever remember having experienced the effect I saw when blasting myself with the DEFT-X. On a sunny day, even when the sun is somewhat low, I have no problem seeing the area around me. We all see just fine despite the intensity of the sun because the light is shining everywhere. Kind of like a reflector light no? Beam me with that MaxaBeam and assuming the distance is relatively close I will have some of that spill light lighting the area around me and helping me to find a way to escape, or attack, or even just helping my pupils to constrict so when the beam hits my eyes it is not as intense as it otherwise would be. It is this effect which is very real that makes an aspheric light more likely to be able to "blind" or disorient. This is in addition to the already well known fact that size for size, like for like, an aspheric will always beat out a reflector light when it comes to intensity. At least when it comes to LEDs. If I were to make a larger light like the MaxaBeam I believe I now have the technology to beat it.
 

houser23

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Feb 17, 2013
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If I were to make a larger light like the MaxaBeam I believe I now have the technology to beat it.

And I will patiently be waiting for that day Michael. Thanks for your dedication to innovative light technology.:)
 
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