Yahoos with Wicked Lasers - strike again...

[Stuka]

As documented in this month's "Rotor & Wing" magazine.

See pages 18 and 64 :

http://accessintelligence.imirus.com...ok/vrw13/i3/p0

[mixedgas]

"I told you so!"
There, I've been waiting for three years to say that! I'm sad to have to say it now. I have to wonder if he rubbed his eye with his glove, but still, it is laser related injury.

When I went to both our local New Years Eve and Fourth of July fireworks, with Orchestra, some yahoo was really distracting with about 300 mW of green on the pavilion walls for THREE hours. Enough!

Steve

[Meatball]

I just wrote Ernie Stephens and nice and long email, about the unlikelihood of "redness on white of eye" occurring from such a device from a such a distance etc. I'll wait and see what he says.

[carlos3621]

http://www.goal.com/en-us/news/4234/...ames-until-you

and another one......

[dzodzo]

http://www.goal.com/en-us/news/4234/...ames-until-you

and another one......

"Many stadiums specifically prohibit laser pens from being brought inside the grounds, yet identifying the precise location of the culprit is problematic for security staff, especially as a new range of green beams can project intense light from half a mile away."

i imagined a hooligan watching a match from half a mile away just to be anonymous when shooting beam to the field... imagine the size of those stadiums... they have to be HUEG!

[dkumpula]

http://www.goal.com/en-us/news/4234/...ames-until-you

and another one......

The last couple sentences in this article sum it up in my mind. These are weapons without a productive purpose. They should be illegal to own, manufacture, sell, or import. I fear that these idiots will only endanger the legitimate and safe use of lasers.

David

[norty303]

I'm struggling to see how the tissue damage to the white of the eye could have originated from the laser at that range. We all know that the danger to eyes is from the infinite focus on the retina.

[mixedgas]

I'm struggling to see how the tissue damage to the white of the eye could have originated from the laser at that range. We all know that the danger to eyes is from the infinite focus on the retina.

Norty,

Think dirty glove rapidly rubbing eye in pain. Or optically aided viewing such as binoculars.

It may not be a direct laser injury, it could be a laser related injury.

I know what they say about the retina having no direct pain sensors, but I don't buy it. When they dilate my eyes to have tests done it hurts like hell.
I've seen more then one case of eye irritation after a laser hit, caused by rubbing the eye.

One way or another, the laser is tied to this. We do not have all the details.

Steve

[Soulstorm]

Norty,

I know what they say about the retina having no direct pain sensors, but I don't buy it. When they dilate my eyes to have tests done it hurts like hell.
I've seen more then one case of eye irritation after a laser hit, caused by rubbing the eye.

Steve

I agree.

About two years back I was hit in the eye from approx 30-40m, with a guesstimated 100-200mW greenie, by a large group of idiots on the street. Mostly right eye and it was off axis. Instant temporary flash blindness, discomforting sensation from the eye. Not so much pain but more the feeling of a splinter that isn't painful but one can tell it's there. Very hard to determine who exactly did it when you can't see so well out of one eye, believe I caught a glimpse of someone telling someone off about it within the group, I may have shouted at them too, however, at a soccer game, that would be harder to figure out the origin. In hindsight I should have called the cops but it would have been a big circle of 'he said she said', with such a large group, plus I was already running a little late for my appointment and a little shocked from what occurred - didn't cross my mind at the time to call the police. These things must be a bit scary for LEOs that are aware of the dangers.


Saw someone locally importing 445nm pointers on that horrible site I like to call 'phasebook', It was heartening to see the comments from various people - plenty warning that such pointers are dangerous and much overpowered for pointing around. Made the annual 'log in to check the site' a little more pleasant. So I guess the message is getting through, just not to everyone unfortunately.


What's really scary is the thought of 500mW-1W DI greens being obtained by pointer assholes future...

[buffo]

The entire article reeks of bad science. No matter though; it had it's intended effect. It's ratcheted up the fear factor.

Sigh... I don't disagree that Wicked is being reckless with their marketing. I don't disagree that 1 watt pointers can be dangerous. I don't even disagree with the prosecution of this idiot or them taking away his prized pointer.

But there's no way in hell that a 1 watt laser fired out of an apartment balcony at a rotorcraft hovering at 800 ft AGL caused that red mark on the policeman's sclera. No way in hell. That statement in the first article really grinds my gears.

Do the math: Let's assume the guy was more or less directly beneath the chopper, so we'll set the throw distance as 800 ft. (It was very likely a much larger number, but this is a worst-case analysis). Now, the beam at the aperture was probably something like 2 mm. (The diode is mounted pretty close to the business end on an Arctic III) And even though we all know the divergence is way, way worse than 1 mrad, let's just use 1 mrad and see what that yields. Go ahead and crunch the numbers - I'll wait...

If you came up with an answer of ~ 250 mm across at 800 ft, congratulations! You passed. Now what does that mean? (For one, it means the beam was nearly 10 INCHES in diameter when it hit the chopper. Think about that for a moment.)

Back to work. We know that irradiance is measured as power per unit area. The power is unchanged at 1 watt (ignoring any atmospheric scattering), but the area of that beam is pi times the square of the radius (which is half the diameter, or half of 250 mm, which is 125 mm or 12.5 cm). So 12.5 cm times 12.5 cm times 3.14 yields an area of 491 square cm. Holy shit! That's huge!

So divide the power (1000 mw) by 490 square cm, and you find that the irradiance was just over 2.0 mw/cm squared. (2.04 if you're using a calculator)

Now, anyone care to recite what the MPE is for a single-pulse exposure that lasts for one quarter of a second (because after .25 seconds you blink)? Yeah, that's right. It's 2.5 mw/cm squared. So this beam in a WORST CASE ANALYSIS was fucking eye-safe according to the most stringent standards (CDRH)! And you're trying to tell me it made a mark like that on his eye? From a beam that is nearly 10 INCHES in diameter? I call bullshit. Complete and total fucking bullshit.

Mixed Gas is right. The guy experienced a distraction, and maybe a slight after-image, and he rubbed his eye. It was the rubbing of the eye that caused the irritation seen in the photo, not the power of the laser beam.

The rest of the first article (and all of the second one) is a bunch of breathless exposition about the supposed dangers of these "light sabers" which illustrates perfectly both authors' complete lack of knowledge on the subject. I can maybe forgive their ignorance, but not their failure to fact-check with an expert before publishing. That's a cardinal sin in journalism. (Or at least it used to be.)

Had the copter been within 50 ft of the laser, I might buy it. But if the craft was that close to an apartment balcony, they had bigger problems than a rouge laser pointer. (Like not crashing the rotor disc into the building, for example.)

How this shit passes for news is beyond me, but it *does* hurt us all when it all goes unquestioned. Someone could have spent 5 minutes fact-checking this, but they didn't. And now everyone who reads it will take it as gospel. Fuck.

And as I said, I still agree that Wicked is in the wrong here, both for the way they market their product and for their "hands-off" attitude about what people do with them after the sale. But banning Wicked isn't the answer. (It's a game of whack-a-mole; someone else will step in to fill the void.) No, the answer is EDUCATION. Both for people who buy and own lasers and especially for police (and other officials) and JOURNALISTS.

Adam