Audience Scanning??

[UV99LASER]

Here is a shot of me recklessly enjoying my race bike on the rear wheel.
Oh and some more big ass pupils.
Skipp
Did I say VIOXX in this post yet?

[UV99LASER]

Here is a few youtube links to emulator videos.
http://www.youtube.com/watch?v=lTemQibTY7Y
http://hk.youtube.com/watch?v=BGHSmIgEFTo
I can pick up six of these and a controller for less than 6 grand.
I can blast everybody in the face no variance needed.
For the price of one varianced audience scanning system I can launch 30 or 40 of these things.

[buffo]

UV99Laser;

For the purposes of this discussion, let's say that *EVERYONE* in the venue is zonked out on their drug of choice and *EVERYONE* now has a pupil diameter of 9mm. Are you happy with that assumption? Good. Let's continue then.

Class 3A Laser radiation has been shown to be incapable of causing permanent damage when exposed to the eye for a minimum of 20 seconds at a time. Yes, some changes in the retina were observable upon very close inspection, but those changes were *not* permanent and were *not* detectable by the subject. (re-read the links in my earlier post above if you've forgotten about this, or see the quoted section below) Remember too, that these tests were performed using a calibrated laser pointer with a power output of 5 mw (figure a beam diameter of 2 to 3 mm), and the entire beam entered the pupil.

And before we continue, a warning: do not try to exaggerate these claims. 20 seconds of class 3A radiation does not "blast retinas", it does not "blow rods and cones", it does not "blow up eyeballs", it does not "cause blindness". It causes minute changes to the retina that are only detectable using very advanced diagnostic tools. You seem to enjoy using these colorful expressions, but they are *NOT* accurate.

In fact, the changes we're talking about are similar in structure to other lesions found on a healthy person's retina in areas of the retina that were never exposed to laser radiation! Furthermore, they do not affect the person's vision, and they go away with time.

Finally, remember that 20 seconds is an incredibly conservative exposure time. Most of the studies I referenced in my original post used exposure times of 60 seconds or longer. (See the "*" quoted section at the end of my post for more information on this.)

Just so we're clear on this... We're not talking about eye *damage* here, we're talking about minor and barely detectable changes in the retina that are not permanent. Even so, this is after a minimum of 20 seconds of constant exposure to class 3A power levels.

Now, we already know that the Pangolin variance specifies a lens that reduces the beam irradiance to below class 3A levels. So by increasing the "standard pupil" diameter in our calculations, we're increasing the cross-sectional area of the beam that can enter the eye, thus increasing the dose (by roughly a factor of 65%, as you correctly pointed out).

But remember, too, that the beam is moving. So the transient exposure duration to the beam is extremely short. This reduces the amount of energy that can enter the eye by *several* orders of magnitude. And keep in mind that the STATIC BEAM is already below class 3A levels.

So, if you can take 20 seconds of continuous exposure to Class 3A level radiation with no permanent effects, how exactly is a .001 second exposure at 65% greater intensity going to cause permanent injury? Do you understand the math here? We're dividing by a factor of 20,000 and then multiplying by 1.65. You still end up at 4 orders of magnitude below the dose rate of the studies that verified the Class 3A limits in the first place!

This is why I said that the 9 mm pupil diameter assumption is irrelevant. This is also why I believe your arguement is nonsensical. Obviously you haven't "done the math" yourself.

Furthermore, you keep changing your objections. First it was "all laser radiation causes permanent damage". But when that was showed to be false, you came back with, ".02 seconds for a blink response isn't representative". But when we showed that the number was actually .25 seconds, you came back with "even .25 seconds isn't enough if you are impaired and intentionally staring at the beam". But when we showed that the beam is below class 3A limits to begin with, you came back with "if you are impaired, your pupil diameter is larger!" But even so, that doesn't significantly affect the dose because of all the other safeguards in place (including the movement of the beam).

I can only wonder what your next objection will be.

No, actually, I don't really care what your next objection is. I've already spent enough time in this thread trying to reason with you. The problem is, you aren't being reasonable, and there's no point in continuing a discussion with someone that refuses to be rational.

However, for those people that are interested in the science behind the issue, I've copied some information below that explains a little bit more about the changes to the retina we've been talking about. (See my previous post in this thread for several other links to more information about this subject.)

Adam


"*" The following except is from this site {http://archopht.ama-assn.org/cgi/con...ll/118/12/1686} and explains the damage to the retina (or rather, the lack of any damage) caused by exposure to a 5 mw laser pointer. The patients were scheduled to have their eyes removed to combat uveal melenoma. (Yeah, cancer of the eye. Pretty lousy.) The bold emphasis is mine.

Continuous exposure was directed to the fovea for 1 minute, to the retina 5° below fixation for 5 minutes, and to the retina 5° above fixation for 15 minutes. Ophthalmoscopic evaluation of the cornea, lens, and retina and fluorescein angiographic studies of the retina were conducted before, 24 hours after, and 11 days after laser exposure in the first case; before and 86 hours after exposure in the second case; and before, 96 hours after, and 15 days after exposure in the third case. Other than transient afterimages that lasted only a few minutes, we were unable to document any functional, ophthalmoscopic, fluorescein angiographic, or histologic evidence of damage to any structures of the eyes. Transmission electron microscopic studies of retinal sites targeted by the laser pointers in the second and third cases revealed ultrastructural abnormalities in the outer retina and the pigment epithelium that were similar to abnormalities seen in the retina approximately 8 mm away from the targeted sites.

Note that the only damage the could find was when they used an electron microscope (!), and then all they found were abnormalities that looked exactly the same as other areas of the retina that had not been exposed to the laser.

[UV99LASER]

accidental over post

[UV99LASER]

accidental over post

[UV99LASER]

"Now, we already know that the Penguin variance specifies a lens that reduces the beam irradiance to below class 3A levels. So by increasing the "standard pupil" diameter in our calculations, we're increasing the cross-sectional area of the beam that can enter the eye, thus increasing the dose (by roughly a factor of 65%, as you correctly pointed out)."

Class 3A levels using a 7mm aperture on your detection equipment I understand.

I am sure that level will increase if you use a larger aperture such as 9 or more millimeters.

Did you not see the pupil pictures. Clearly these people have pupils in excess of 10MM. Compare the pupil size to dudes fingers in the one picture.
In the one opthalmic picture the eye is at least 13MM dilation.
Again I have seen pupils close to 13MM in public.
This would double the dosage over a 7mm aperture.
How can you say this irrelevant?

Yes I have already read the report at http://archopht.ama-assn.org/cgi/con...ll/118/12/1686.


You should red this one. It is on the same site.
http://archopht.ama-assn.org/cgi/con...ABLEESA30014T1
Recovering for 3 months from an injury hardly sounds harmless.
Here are two laser pointer cases
In the first one there is injury. In the second there is none.



CASE 1 History
An 11-year-old girl stared at a red laser pointer beam held close to her right eye for more than 10 seconds to satisfy the curiosity of classmates on a school bus who wanted to know if her pupil would constrict.61 She experienced no pain but developed decreased vision and a central scotoma immediately in her right eye. Three weeks later, a retinal evaluation revealed central foveal pigment mottling with corresponding faint hyperfluorescence on fluorescein angiography. These findings became less prominent during the next 3 months as her scotoma resolved, and her uncorrected visual acuity returned to 20/25 OD, the same as in her unaffected left eye. She had no other ocular abnormalities in her right eye. In addition, this patient had no recent history of infection, inflammation, or mechanical trauma and no contributory past systemic or ocular history.
Analysis
This 11-year-old girl probably experienced a 5-mW, 10-second, 50-µm retinal spot diameter exposure that produced a 6° to 10° retinal temperature rise with a retinal irradiance of 160 W/cm2 of diode 635-nm red light.5, 62 In comparison, clinical photocoagulation for diabetic retinopathy can be performed with a 200-mW, 0.2-second, 200-µm retinal spot diameter exposure that produces a 40° to 60° retinal temperature rise with a retinal irradiance of 325 W/cm2 of argon laser 514-nm green radiation.62 Subvisible lesion transpupillary thermotherapy for occult choroidal neovascularization in age-related macular degeneration can be performed with an 800-mW, 60-second, 3-mm retinal spot diameter exposure that produces a 10° retinal temperature rise with a retinal irradiance of 7.5 W/cm2 of diode laser 810-nm infrared radiation.62
Laser pointers sold in the United States are required to have an output power less than 5 mW.1-2,5, 63 Accidental momentary laser pointer exposure is safe because it is terminated in less than 0.25 second by normal aversion responses to uncomfortably brilliant light.1-2,5, 64-65 Prolonged viewing of a laser pointer beam for more than 10 seconds is potentially harmful,1 which is the reason that these devices have warning labels. Retinal irradiance produced by a laser pointer held close to the eye is high because much of its power enters the eye and is concentrated into a small retinal spot. Conversely, heat conduction cools small retinal spots more effectively than large ones, so retinal temperature rises for small-spot, 10-second laser pointer and large-spot, 60-second transpupillary thermotherapy exposures are comparable.11, 24, 62 Thus, the most likely mechanism for the documented retinal damage caused by this laser pointer exposure is threshold transpupillary thermotherapy–type photocoagulation. In this case, the answers to all 6 diagnostic questions given in Table 1 are "yes," and this episode is a case of laser injury.
CASE 2
History
A prankster with a laser pointer momentarily exposed a middle-aged worker to the beam of an ordinary laser pointer from a distance of 9 m. The worker's visual acuity after the incident was 20/20 OU. In the 4 years after the episode, the worker developed headaches, progressive photophobia, and severe sharp and longer-lasting dull eye pains. His photophobia was disabling even when wearing sunglasses at ordinary indoor illumination levels. Visual field tests initially documented unilateral hemianopsia, although findings from magnetic resonance imaging were normal. Fluorescein angiography and eye examinations by numerous ophthalmologists immediately after and subsequent to the episode did not identify organic disease other than dry eye syndrome. The worker was then seen by a neuro-ophthalmologist, who diagnosed him as having photo-oculodynia syndrome66 and attributed the origin of his pain, photophobia, and headaches to previous laser pointer exposure. The prankster's foolishness, the neuro-ophthalmologist's speculation that momentary laser pointer exposure can cause photo-oculodynia syndrome, and the worker's excellent employment record and reported absence of health or occupational problems before the incident probably influenced the defendant to settle this worker's damage claims out of court.
Analysis
Laser pointers are poor optical devices that contain a simple, inexpensive lens that collimates its diode laser's divergent, astigmatic beam. Assuming that a laser pointer beam has a full 5-mW output and a standard beam divergence of 1.5 milliradian, only 7% of the laser beam would enter a 4-mm-diameter pupil at a distance of 9 m. This exposure would produce a physiologic retinal temperature rise of only 0.4°C, which could not cause retinal injury. Furthermore, at a distance of 9 m from an artificial pupil, a laser pointer can be aimed through a 7-mm aperture at best only 25% of the time (B.E.S., D. J. Lund, BS, H. Zwick, PhD, D. A. Stamper, MS, P. R. Edsall, BS, J. W. Molchany, BS, unpublished data, 1999). Normal head movements and hand movements reduce any retinal exposure even more, so a laser pointer injury from a distance of 9 m is impossible without pupillary dilation and mechanically restraining and aligning both the laser pointer aperture and the observer's pupil for more than 10 seconds.
We could find only a single article66 in the medical literature on photo-oculodynia syndrome, which is described as "a category of chronic eye pain triggered by even minor ocular trauma, when there is no evidence of ongoing tissue damage or inflammation." The term was proposed as an alternative to the standard term "photophobia."66 Only 6 individuals with this condition were described in the article,66 3 of whom reported less discomfort after cervical sympathetic ganglion block. There is no scientific basis for the neuro-ophthalmologist's speculation that a complex ocular pain syndrome could be induced by brief, nondamaging light exposure. If that were the case, there would be millions of people with photo-oculodynia syndrome due to flash photography and laser eye surgery. In this case, the answers to diagnostic questions 1 and 6 in the Table 1 are "no," and this episode is not a case of laser injury.




Six Questions That Facilitate the Diagnosis of Alleged Retinal Laser Injuries



It Is MY OPINION that audience scanning it is a bad idea.
It is also my OPINION that 7MM pupil dilation is a bad number.
It is also my OPINION that the penguin system uses large diameter beams whose total power is more than 5mW in total beam power.
I further understand that a 7mm cross section of said beam would be less than class 3A. This is the basis of the safety claim.

So are you actually saying that if you use the penguin system and you make a mistake in your calculations or power settings that the penguin will auto fix the problem and prevent over exposure?
Are you saying the penguin system is foolproof?
Are you actually saying it can not be misused?

You keep saying IF the protocols are followed THEN it is safe?
That is a big IF THAN statement.

For all the money spent on this effect and all of the safety protocols that need to be followed it would be cheaper and safer to produce the same effects with a light bulb.

See the emulator.
This was a safe product that emulated a laser. I think the beam size is similar to the penguin beam size.
At the time the fixture was around $4K each.
You can pick them up used for less than $1K now.


CHANGE MY OPINION PLEASE.
PLEASE ARGUE WITH MY opinion.
Arguing against an OPINION makes little sense?
Are you really out to change my mind?

Lemming

[cruch]

OMG!!!
There is no need to spam!! Get real!

[buffo]

Did you not see the pupil pictures. Clearly these people have pupils in excess of 10MM. Compare the pupil size to dudes fingers in the one picture.In the one opthalmic picture the eye is at least 13MM dilation.Again I have seen pupils close to 13MM in public.
This would double the dosage over a 7mm aperture.

There you go again. Moving the goal posts. I do the math to show you that your 9mm pupil objection is irrelevant (because you're still below MPE), so now you're worried about a 13 mm pupil diameter...

That's it. I give up. You are not participating in a rational discussion, you are trolling (at best) or simply being irrational (at worst). Either way, I've got better things to do with my time.

How can you say this irrelevant?

Do the math for yourself. Or read my post above where I did it for you. Oh, never mind... You'll just come up with some other excuse to continue this nonsense.

You should red this one. It is on the same site.
http://archopht.ama-assn.org/cgi/con...ABLEESA30014T1
Recovering for 3 months from an injury hardly sounds harmless.

We've been over this before. Anecdotal stories from a patient are *NOT* a substitute for peer-reviewed research done in a hospital under controlled circumstances. But whatever... You've already proved that you are irrational, so why not cite some even more impeachable sources?

It is also my OPINION that the penguin system uses large diameter beams whose total power is more than 5mW in total beam power.

It's "Pangolin", not "Penguin" you insensitive jerk. Your smugness hurts your already diminished credibility.

It Is MY OPINION that audience scanning it is a bad idea.
It is also my OPINION that 7MM pupil dilation is a bad number.

Fine. You've stated your opinion. Leave it at that. But if you start making wild claims about how other people's variances are unsafe again, you're going to get called on it again. And if you make other factual statements that are clearly false (like "all laser radiation causes permanent damage to the eye no matter what"), you will be called on it as well.

CHANGE MY OPINION PLEASE.

That would require you to have an open mind, which you clearly do not. I'm through wasting my time trying to explain the facts to you.

Adam

[UV99LASER]

Oh that is great I am an insensitive jerk now because I like penguins.
I have a better response for you but I have to go now and do a show for BT tonight in San Francisco.
That would be in the real world where penguins live.

Skipp

Oh Yeah VIOXX and penguins

[dsli_jon]

http://www.youtube.com/watch?v=-is63goeBgc

sorry, couldn't resist...

(prolly a good thing there is ~2,500 miles between you two!)

peace...

- J