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ArcticMyst Security by Avery

WL Lasershades for red - debunking myths

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Oct 24, 2006
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Well this probably sounds extremely rude out of context, so you should refer to the post "WL goggles" (in which there are many unsubstantiated attacks towards WL's lasershades) at http://www.laserpointerforums.com/forums/YaBB.pl?num=1213721006/48 for the background. I originally made this post as a reply there, and I figured the data was useful enough to make a separate post about so here's a copy of the original:

pseudonomen137 said:
Sick and tired of BS and misinformation

Tired of it all so I went and restested a brand new pair of WL lasershades for red - brand new out of the package. I do not have the proper equipment to precisely measure OD, but I daresay my equipment and methods are gunna provide you with far more factual numbers about the lasershades than ANYTHING in this thread so far even gets close to.

So tests were conducted with ~660nm sources. OD was found to be in the 2.5-3.0 range, with my personal estimate (ignoring the margin of error I calculated into the 2.5-3.0spec) set at 2.7OD. The goggles were also shown to be capable of withstanding direct exposure to 300mW of longitudinally multimode 660nm at a diameter of ~5mm for an indefinite period of time with no degradation in material or increase in transmission.

Until I see similarly reputable tests posted saying otherwise, I hereby declare this post the fact of the land... watcha gunna do about it? Test them yourself would be my suggestion. If proper equipment says I'm wrong, that's one thing and I'm fully willing and ready to cede. If I'm only countered by more unsupported argumentative banter though, I'm just gunna be arrogant, plug my ears and shout "I'm right and you're wrong" till I hear a REAL argument. Sorry but that's my stance and I'm sticking to it.


This post is not to say WL goggles are the best there are, its just reminding us all that they are decent goggles, and for the price it baffles me how anyone can complain about them!
 





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Oct 24, 2006
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Update from the original post:

pseudonomen137 said:
Sorry erdabyz but as much as I'd like to help out, I simply don't have the time to provide the media I wish I could. Not only is my video camera in for repair right now, but when I go to take pictures and vids of what I do I go all-out to try to make sure its done right - a process that can easily eat up my day. You can see past stuff on the subject here though: http://s105.photobucket.com/albums/m218/lasers-ch/?start=60
http://s105.photobucket.com/albums/m218/lasers-ch/?start=40
Those pics show the NoIR goggles that block out all red, as well a wonderful pair that used to have OD1.5+ (great for hobbyist red use, you don't really need more than that at 150mW) but unfortunately are no longer sold at attractive pricing.

I don't know why WL claims the goggles from NoIR are 2.5OD. Last time I heard word from Steve of WL about these goggles, I was told the last ones I received would be the only ones they would stock from then on. The ones I have are clearly NoIRs 'KRR' goggles and WL's site even confirms this - although the wrong OD chart is displayed (whether accidentally or intentionally is something I don't know, or feel is pertinent to the conversation). You can read about the KRR filters here:
http://www.noirlaser.com/filters/krr.html
As you can see, the filter is rated OD 5+ across 606-694nm, and for the 660nm red most of us use, the OD appears to be around 6 - letting less than a millionth of the light through and explaining the visibility issue. (NoIR has the same issue with the goggles that are sold by NovaLasers for green although the spot is slightly visible as a yellow fluorescing dot - you can actually see pics of that on the 2nd page of my photobucket site I linked above).


And while I can't provide pics, I'll try to give a rough idea of my test method: red diode lasers ~660nm were used for their ability to be very stable without active cooling. All tests were conducted on a Coherent Inc. FieldMax II TO power meter with a PM3Q power sensor with a 0.050mW sensitivity/resolution. Several lasers were tested across the 40-300mW range (unfortunately I only got to try a 900mW 660nm whilst in passing to a customer ;)) to make sure figures were consistent.

In the end, the test I used to derive the numbers was from my PGL-III 660nm putting out ~290mW (200mW versions of this unit were sold by laserglow for $589 as the Orion). Power was tested with the laser shining through the goggles into the sensor, and given enough time it stabilized at ~0.575mW. I then removed the goggles and measured a reading of 293mW. Mathematically, that corresponds to an OD of around 2.707. My claim of OD 2.5-3.0 corresponds to a potential range of readings from 290 to 917 microwatts through the goggles from my 290mW laser - a range in which my 575 microwatt reading, although not perfectly stable or precise, fit comfortably enough within that I felt safe to make the OD 2.5-3.0 claim.

Noticing no burning patterns refracted through the goggles like I have seen shining while powerful green lasers at 532nm goggles, I furthered the test and ran my 290mW laser through the goggles into the power meter for over 10 minutes to ensure the power output held stable and consistent.


So yeah. I'd also like to point out that I do this in the name of the goggles I have recommended for so long, and even sold from time to time. I have no interest in saying either SenKat or Electron are right in their argument, I simply want to make sure the long held truths about the lasershades are not tarnished by the misinformation that flies out from a silly argument.

If you have any questions or complaints on the topic of the goggles or my test methods, feel free to ask/shout them to me. I wish I could provide pics and vids backing this up to, but I really have better things to spend my weekend doing. There's the old addage "a picture is worth a thousand words", so I can only hope my thousand words can work in reverse to paint the picture you need.



PS: Don't worry, my English it typically worse than yours and I AM from an english-speaking country :D

[quote author=erdabyz link=1213721006/60#61 date=1215892128]pseudonomen137, pictures of the testing process, please.
I said it before, I WANNA SEE WITH MY (hope undamaged) EYES HOW GOOD OR HOW BAD ARE LaserShades. I won't trust anybody since I see something real (photo, video...). The only thing I can belive in this moment is that certified is better than not certified. And since I'm planning to make a BR DIY, i'll probably buy certified 405+650 goggles and sell the lasershades.

I'M GETTING CRAZIER BY MOMENTS with this trouble.

Ahm, another question.

NOiR Sprot elite claim to be 2.5OD. Okai, if LaserShades are 2.7 OD, then why don't you see anything red with Sport elites and you can perfectly see the spot with LaserShades, if LaserShades have more OD?

Sorry, i know my english is bad (i'm not from an english speaking country). I put all my efforts to spell correctly.


EDIT:To make things clear, I don't know anyone of you, I don't know if you have personal problems or if you hate eachother, and I don't wanna know it. And i'm not gonna get influenced by your personal discussions. So please, if you want to really help me, stop personal attacks and all similar BS.
[/quote]
 




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