OK, so what exactly is the definition of 'crowd scanning'

[wseaton]

I support the light shows for a couple of entertainment complexes, and while most of my stuff is LED I'm increasingly integrating lasers into the mix because, well, it generates revenue. With the price dropping on laser projectors it's also more financially viable. I shudder to think of the price I paid for my green Q-beam.

In any case, I've read all the debates and drama about crowd scanning, and since we operate in the U.S. I could care less what's not enforced in Europe. From an automation and low support perspective I prefer to simply flat scan my lasers (.2-1watts) over the crowd because (1) it requires a very simple projector, (2) is easy to align (3) has a very good 'wow' factor and (4 most importantly) inherently safe with no controversy, or so I thought.

The issue I'm having is determining how #4 meshes with actual laser guidelines, or if I should care and just keep using common sense while keeping the beams out of reach. My existing variance is rather old, and rather vague as read verbatim. As I read some FDA guidelines verbatim flat scanning above a crowd still constitutes 'crowd scanning' because a troop of cheerleaders might come in and start doing pyramids. I'm of course paraphrasing the last part out of cynical frustration.

[mixedgas]

Depends, there are three possible classifications, and one is, Any exposure less then Class I, NO exposure at all, and Not exceeding Class 3A or similar MPEs. Depends on whose read of the rules you interpret, the company that built the hardware, and what actual testing is done.

Only three or four companies can legally install unattended high power audience scanning in the US. Otherwise the rules state 3 meters up from the floor at the highest accessable audience point in the beam path. Then two meters horizontal from any point the audience can reach from.

What you can expose the audience depends on the power of the laser, its wavelength, its energy, the beam diameter, how fast its scanning, the pattern it is scanning, and a variety of other factors that need to be determined by the system designer. The math is not hard, but it is very time consuming if you have more then just a few programmed effects.

There are some low powered things that are sold to clubs as being Class IIIA and nearly eyesafe. Some of them actually are.
Others (Cheap Asian Clones) do not have quality controls and testing done on a device by device basis and break the rules.
Some of them have very high power, well in excess of what would be legal.

I'm not worried about the cheerleaders, they are too busy getting free drinks at a club to do pyramids. I'm more worried about mylar balloons, Coors cans thrown into beams, and guys "chickenfighting" with their girlfriends on their shoulders. It does happen that people will try to get into the beams, and with a laser more then say a few 10s of milliwatts, the risk of eye damage becomes VERY real if the beam is static and not scanning. There is more to it then just scanning the beam rapidly.

The FDA//CDRH/IEC exposure rules were chosen so your staff and patrons have a low probability of risk.
Ie none if not audience scanning, and say 1 in 100,000 or 1 in 10,000 for Audience scanning.

This is getting into the realm of "MPE" Maximum Permissable Exposure, which is a carefully choosen level of light that will not damage eyes. Its also cumulative for prolonged exposure. It takes a bit of work to calculate it, and it has to be calculated for each effect presented.

X-Laser has a audience scanning product coming out that is legal, and Pangolin offers a control system called PASS for it as well.
These feature approved hardware devices and some software that goes into the projector, and makes the headaches go away.

Many of us here have attended ILDA (International Laser Display Association) or Professional Consultant based classes on Audience scanning, and a few of us have actually done it with the calculations, measurements, etc.

There are also laser safety consultants I can send you to.

Its a beautiful effect, and a lot of people do it illegally, with seemingly no ill results. But when illegal uses go wrong, there will be nothing left when the lawyers get done with you. Often times, for clubs, a better effect can be designed without audience scanning if you have tall ceilings and a modest budget, and the right control software. There have been a few "nightmare" cases of industrial lasers being repurposed in the US and Europe, and this is why we have the draconian rules in the US.

You just picked one of the toughest questions that can be asked about laser shows, so it will take some time to flesh this out. You'll also see some debate in this post.

I lost my job yesterday, my contract ended, so I'm busy updating the resume. When I get that done, I'll come back and fill you in some more. AELs, Power Classification levels, and a bunch of other stuff factor in.

So make sure when you read the answers here, you get qualified responders. Its been 10 years since I took the ILDA course. I do industrial MPE work some times for my former employers, so I can do the math, but the licensing procedures have changed in the last 2-3 years for club stuff. A few vendors have done the math, testing, and legal legwork for approval in the US, but VERY few actually have it documented.

Many vendors claim approval, but do not really have it. Enforcement is lax, but there are a few regions of the US that really get out and enforce.

If your a technie/skilled nerd, engineer etc, The math is simple and high school algebra will do. The required equipment is a very good laser power meter, a fast photodiode, and a decent oscilloscope. Then you have to really discipline the show operators to follow the rules, and do quality control every night. I've published the government's own sample calculations document here. However there is no incentive for the powers that be to add a simple variance amendment to allow you to do it.

So if you really want it, buy it from the vendors that really have it.

Steve

[wseaton]

Hey dude, sorry about the job.

I also appreciate the input on this. Please understand I'm not trying to be arguementive but trying to get as much information as I can while venting..... a lot.

I'm more worried about mylar balloons, Coors cans thrown into beams, and guys "chickenfighting" with their girlfriends on their shoulders.

In the decade we had our Q-Beam we never had a problem with any of this. If I may ask a question, what particular 'safety' device does a 'legal' laser have that an 'illegal' does't have that allows it to detect when a beer can or mylar ballon floats into the beam? Xlaser have a patent on this? :-)

I get the 2 meter safety height as an arbitrary guideline and transient radiation exposure calculations, but in all seriousness how much does this really matter. I'm not crowd scanning, I have no intent to, but I can't quite accommodate that two meter margin spec. I'm also not going to be extorted into buying the Xlaser product because it (on paper) meets a bureaucratic guideline so I can have the privilege of staying at a 12foot level. I don't have trouble with people getting 12feet up in the air, but I do have trouble with punk kids and their 1.5watt laser pointers shining them at glasses and such and the occasional idiot packing a handgun in his coat. I'm not going to hire somebody to push DMX buttons and hav to pay for their salary by a 20% increase in prices.

So if you really want it, buy it from the vendors that really have it.

{sigh} The additional money required to buy a product to accomplish the same effect (and identical safety risk) isn't worth it to me. I'm not Trans Siberian Orchestra, but I'm also not some garage band firing their chinese projectors in to a crowd 10feet away. I'm stuck in the middle. I'd rather buy more 60watt LED scanners and trash peoples eyes that way because I don't have the hassles to deal with and can buy what I want.

[White-Light]

I'd rather buy more 60watt LED scanners and trash peoples eyes that way because I don't have the hassles to deal with and can buy what I want.

Its not just about brightness. The danger with lasers comes from the coherence and the tight beam specs that result in a very concentrated beam of radiation that has heating effects.

However, I think you may have just answered your own question.

There's only two way to do lasers - legally and illegally. Take the latter route and you might get away with it, but if you don't, you face prosecution and if damage occurs, lawsuits, which in a club could run anywhere from 10's to thousands of claims depending on the size and time taken for people to realise damage is being done, if anyone even does so at the event itself. Afterwards could be far worse as more people have been exposed. Either way in the US at least where damages are high, you could end up personally bankrupt if not worse.

Chinese lasers are great for home use but for commercial use, you need something varianced in the US.

[buffo]

This is going to be long, and more than a little unpleasant. I apologize for that in advance. But you really need to read all of this, because you've got some wildly-misguided perceptions about laser projectors and laser light shows in the United States.

I get the 2 meter safety height as an arbitrary guideline

First, it's 3 meters, not 2. The 2 meter rule applies to horizontal separation where the audience could reach past some barrier device and otherwise get a body part into the beam.

But for overhead beams, they must be at least 3 meters above the highest point in the audience where a person could reasonably stand. So stairwells, bleacher seats, and handicap ramps all count, but tables and chairs do not. (Unless you've got people routinely dancing on tables, which I have seen at more than a few clubs...)

Second, your earlier statment that your variance is "old and vauge" sounds very odd, and frankly more than a little suspicious. Your variance needs to be renewed annually - there is no such thing as an "old" variance. If you haven't been filing your annual renewals, you are already illegal - period. And be warned that the CDRH has recently stepped up enforcement on this very topic; I know two people who have received cease-and-desist letters in the past 8 months as a result of this effort, and one has pending legal action (read: fines) against him.

Also, there is nothing vague about a variance at all. If you understood enough about 21 CFR 1040 to file for the variance in the first place, then you should easily understand the language they use in the variance approval letter.

I'm not accusing you of outright fraud, but from the content of your posts above it appears that you've been skirting the law with little concern as to whether you are actually in compliance or not. (And an unattended Q-beam is *definitely* not covered under a standard variance.) Whether that's a matter of ignorance or malice is unclear, but as far as the CDRH is concerned, it doesn't matter. They don't give extra points for not knowing that you were breaking the law.

what particular 'safety' device does a 'legal' laser have that an 'illegal' does't have that allows it to detect when a beer can or mylar ballon floats into the beam?

This is covered under the general clause of "audience unruliness", and it's the primary reason you *must* have a trained operator present at all times while the laser is in operation.

It would be prohibitively expensive (and hideously complicated) to design an automated system that could detect a flying beer can and shut down the laser in time. So instead, you have a trained operator present (who is supposed to be monitoring the audience and the beams). If he sees something that could render the show unsafe, it's his duty to shut down the show immediately. (This should not be news to anyone who already holds a laser light show variance.)

in all seriousness how much does this really matter.

It matters a lot. If you are not following the federal requirements, you are automatically negligent. No way to deny it. You knew about the regulations and you willfully violated them anyway. Now if someone even CLAIMS to have been injured, you are well and truly screwed. Because when the case goes to court, they're going to ask you why you weren't folowing the rules. What can you say? That you thought it was safe enough so you figured it was OK? That you knew more about laser safety than the US Food and Drug Administration?

The key is that they don't even have to prove that it was your laser that caused the damage. It very well could have been caused by a rogue laser pointer in the audience. Doesn't matter. Civil cases are decided based on a "preponderance of evidence", and the big damning evidence they have in their favor is that you knew about the rules and decided not to follow them. Bam - cripling judgement against you and your company.

The other effect is more insidious. Even if you manage to declare bankruptcy and avoid the payout (or through the structure of your business - an "S" corporation perhaps - you otherwise manage to avoid losing all your personal assets), you have still left the entire laser light show industry with a black eye. And in this country, saddly, it doesn't take very many black eyes to cause real damage to an industry's image. In the court of public opinion, it's not just "WSeaton Laser Company" that did something wrong, but rather "Those reckless laser companies". So it hurts everyone. (As an example, think about how much flak the laser light show industry has had to weather because of backyard idiots shining hot laser pointers at airplanes...)

I can't quite accommodate that two meter margin spec.

It's not 2 meters, it's 3. And it's measured off the floor. What kind of tiny club do you have where you can't get the beams 10 ft off the floor? (And how on earth did you ever get a variance without understanding this most basic fact about laser light show safety?)

I'm also not going to be extorted into buying the Xlaser product because it (on paper) meets a bureaucratic guideline

Fine. Then file for your variance yourself. Lots of people here on PL have done it. It's not impossible by any means, and we'll gladly help you do it.

If you are using a stock Q-beam unit that has not been modified in any way, then the original laser product report for that unit is still valid. Thus, it is a properly certified laser projector that has been certified under a manufacturer's variance. (Probably Lumalaser's manufacturing variance, since I believe they bought out both Q-beam and Mobolaser a while back, though it would be wise to double-check that before you file just to be sure.)

In any case, since the projector is already certified, all you need to file for is the laser light show variance. It's a two page form. True, you'll need to attach a show report stating how it will be set up in the club, but that's simple. These days the CDRH has about a 60-day turnaround on light show variance applications.

Trust me, this is the easiest part. Getting a light show variance is trivial if you already have a certified projector. (The hard part is getting a manufacturer's variance and filling out a lengthy laser product report to try to certify a home-built projector, but even that is well within the abilities of your average hobbyist, as proven by the several members here who have done exactly that.)

I do have trouble with punk kids and their 1.5watt laser pointers shining them at glasses and such

All the more reason you need to be absolutely certian you are legal in every way. Because sooner or later someone is going to take a hit in the eye from one of those hot laser pointers, and they're not going to try to sue the knuckle-dragger who is sitting at the bar. For one, they have no idea who he is (or was), and he probably doesn't have any money anyway. But they damned sure could sue you, and since you're a business owner you probably have insurance, so any lawyer-shark worth his salt will see settlement dollar signs in the future and sign up on contingency...

I'm not going to hire somebody to push DMX buttons and hav to pay for their salary by a 20% increase in prices.

If you are going to do laser light shows here in the US, you need a trained operator present, period. If you decide that you're not going to do that, you are willfully violating the law. (And it's a federal law at that.) Ok, sure - maybe you won't ever get caught. But if you do, you won't have a leg to stand on. You really want to take that kind of risk? Even if no one ever claims an eye injury, a single inspection could shut your whole business down. Why would you risk that? Are you really saving that much money by not having an operator? Or is your business that weak that one more staff member will sink you? (And if so, then you've got bigger problems than just how to run your laser...)

Other people play by the rules and still make a good profit... What is so special about your operation that you can't do the same? (Especially when we have hobbyists here on PL who don't even own their own business yet and they still have their variances...)

The additional money required to buy a product to accomplish the same effect (and identical safety risk) isn't worth it to me.

Fine... Then don't. No one is saying you have to have lasers in your club. Hell, there are some awesome moving head fixtures on the market these days that at reasonably close range can fool just about anyone into thinking that they're looking at a laser. Another option is a high-contrast-ratio DLP projector. Pangolin just announced support for using video projectors as display devices in their new Beyond software. So that's another way to get laser-looking beams without all the hassle. (And a DLP projector can be run all night with no operator present.)

But don't expect people who have been playing by the rules all along to suddenly feel sorry for you because you don't want to go through the work to do things the right way. If you want help getting legal, the people here will bend over backwards to assist you. (Myself included.) We all gripe about how overly-restrictive the regulations are, but at the end of the day we all agree that it's easier to do the right thing, and it's also better for everyone. That's why we help each other. Everyone wins.

However, it sounds like you'd rather try to convince us that you deserve some special exemption because you think it's too much work. That's not going to happen. And in the mean time, it's going to piss people off. (Rightfully so.)

I'd rather buy more 60watt LED scanners and trash peoples eyes that way because I don't have the hassles to deal with and can buy what I want.

A 60 watt LED panel that is 3 ft away is still far less hazardous to the eye than a 1 watt laser that is 30 ft away. Lasers produce monochromatic, spacially coherent, low divergent beams that when focused with a lens (like your eye) will be reduced to a diffraction-limited spot that is microscopically small. Thus the power per unit area gets enormous. (5 to 6 orders of magnitude greater than the light from the sun!) The two products really can't be compared effectively, because they are so far apart. It's like the speed difference between a tricycle and the space shuttle.

Adam