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i applaud your interests and enthusiasm with regards to your laser endeveors. however, some of the questions youre asking are almost impossible to answer.

please dont misconstrue what i am saying. i am in no way putting you down or putting your questioning down. but asking what type of smoke and particulate is needed for outdoor lasers is a fairly obscure and general question.

1. you need to decide if doing outdoor shows, will the laser be used to do beam effects? (crowd looking toward the beam source and the laser projecting OVER the crowd to obtain the effects). if this is the case, than i am sorry to say that you are going to need exponentially more money and laser inventory than what you plan on spending.

i have a 3 WATT yag (approx brightness close to a 10W argon). and if the weather and air outside doesnt cooperate PERFECTLY, and i mean PERFECTLY...it is VERY hard to see anything more than a slow moving fan of 5 or so beams. if you add in a BIG, BAD ASS, SUPER DUPER fogger, that will help for about 5 seconds after the fog is let loose from the machine. and ONLY if it can remain close to the laser.

in fact i was at a show (not mine) with a 40 watt yag on a very dry night with no fog. and THAT was almost impossible to see. in fact the client complained becasue the laser wasnt too impressive. (at no fault of the operator)

so, outdoor laser displays are next to impossible to predict. in fact, in my contracts i actually have a little disclaimer in there for outdoor shows for EXACTLY this purpose. it is just WAAAY too hard to know how its going to look.

you can have the biggest, baddest ass, multi-mega watt laser in the world....if there is nothing in the air to scatter the light, its going to look like a piece of crap $10 5mW laser pointer.

2. if you want to do PROJECTIONS (graphics) with the laser, now THAT is a little more forgiving. where as the "crowd" will be looking at the END RESULT of your laser. NOT at the beams. in fact, it is more desireable to have NO scattering in the air for that! you are worrying about the projections and graphics you are "drawing" with your laser. everything the laser has to "shoot through" (i.e.- fog, dust, haze, smoke...etc...etc...) is going to degrade the laser quality and brightness quickly and easily.

it doesnt take too much power to show off a good projection. especially for a backyard, "hobbyist" type of display.

shit, 50mW and up of green could display pretty good on a nice white wall. especially up close. in a smaller area. not in the middle of a football field obviously.

all of the projectors that were at selem could probably EASILY be used to do a pretty decent (smaller crowd) outdoor display.

again, outdoors for projecting graphics (NOT beams) you dont care about fog and particulate in the air. so in essence, outdoor or indoors doesnt really matter. (obviously i am refering to when it is dark out.)

if you are looking to "WOW" a crowd, with a quote on quote, "LASER SHOW," than i am sorry to say its about multiple projectors. bright graphics and raw powerful beams!

-Marc

Ok still a bit off the original topic, but we're on a roll, thinking laterally here.

If all the previous outdoor suggestions fail as impractiacable, what would be the effect of putting the projector in a darkened hazed room inside a house and then leaving the curtains to that open so those at the BBQ could see inside. Has anyone tried this? Would the beam display be visible inside the room when looking in but just disappear at the window?

Having just seen multiple projectors in action (indoors!) at SELEM, I would say your best bet would be to host the BBQ outside, then invite everyone inside for a cold brew and a laser show!

Provided you are using the necessary safety precautions and REALLY know the capabilities - and shortcomings - of your hardware AND software (including DMX controls, if applicable) an indoor laser "beam show" could be one of the safest, coolest crowd pleasers you'll probably ever come up with !! For that to happen, the audience DEFINITELY needs to be in the same room and on the "receiving" end of the lasers, with beams carefully placed and controlled so they shoot ABOVE the heads of everyone. Or, keep it REAL simple (at least as far as equipment placement concerns), and shoot graphics synced to your music on the wall opposite the audience

NO AUDIENCE SCANNING until you have a LOT (i.e several years!!) of hands-on experience and are very familiar with (and can afford) all the equipment needed to reduce hazards and meet the requirements to pull that off safely!! :)

I got like SUPER lucky. A very good person, rMuD, hooked me up with a whole pre-hand-made projector, that I had only to tweak a bit to get going. And when it got going it was just enough for me to do what I needed to do. I agree with the Darwin Theory of laser projector development. If you bite off more than you can chew, you will get eaten yourself. Please be super careful, ask a lot of questions. I have seen for myself at SELEM, there are absolute MASTERS of laser hardware associated with this PL. Take it as it comes from getting to know them. Don't expect to find it all in one place unless, of course you come to a PL organized LEM. I would still not do a thing myself to make a new rig without consulting this group on the details; NOTHING AT ALL. There's a post here somewhere about me taking my rig to SELEM and getting it tweaked by "those who know". :D It's a whole new deal, man! :eek:

James. :)

Stuka as a big trance club fan, audience scanning is the only option for me, apart from the fact that I live in a modest semi with 7 ft ceilings!

However, I'm aware of the risks, so it is my intention to keep these to a minimum. I applied in May for some software, Scanguard I think it was called although I have got it yet. I hoping this will make MPE issues manageable. Last thing I want to do is burn holes in the vision of myself or my guests!

On the subject of powers, what is the best level to go for with RGY? I don't want a weak laser effect but at the same time, I don't want people staggering around blind.

Just diverging for a sec, since last night I thought of an alternative to indoors - we have a car port thats about 30 feet by 12 feet. I can see no reason why I couldn't drape a large black tarpauling around the open side and front to create an outside "room" that I could then haze and hold the BBQ in there, provided the winds were very light. I have access to a gas BBQ so fire smoke wouldn't be an issue.

Question on power though, if I was to haze an outside "room" what kind of level is going to give me bright colours? Within my budget I've seen RGY at 140mw, 190w and at the top end of my budget, 350-400mw.

Ideally this is the kind of brightness I'm chasing:

http://www.youtube.com/watch?v=qXpI7ezv3lA

The brightness in this video looks great, but I can't tell if its been saturated as that looks like either a very powerful laser or exagerated colours to me, although the blue box on the table looks normally saturated.



http://www.amonstar.com/web/laser/c16.jpg

The above still is a pic of another projector (140mw claimed) from ebay although without ILDA and a slow scan speed, I doubt I'd be tempted for this.

Problem is, I don't know if these guys have cheated and saturated. The rest of the pic looks unsaturated but the beams look very bright in a semi dark room for me with 140mw. Other videos I've seen have hardly shown a visible red with 100mw power. I'd have expected nearer 0.5-1w power to get that brightness from what I've seen elsewhere.

Anyone got any thoughts? 140mw, 190mw or 350mw RGY, also bearing in mind I want to audience scan hopefully eventually with MPE calculations if my software ever arrives, although initially I might have to risk sound to light without any kind of pc control.

Sorry Al, but the more I read your posts the more worried i'm becoming. You're talking about potentially using a 350mw laser in a small room to audience scan. There is no way on this earth that you are going to get enough divergence on those beams to ensure audience safety at such close proximity to the laser. You *MAY* be able to increase the divergence with some external optics assembly (such as a negative lens) BUT that's still waaaaay to much power at such a close distance. You really do need to look into this much more, I work in optics and am very aware of the fact that you only get one pair of eyes to last you a lifetime!!

Can I respectfully make a suggestion, for your benefit AND the benefit of all those poor people who will be on the receiving end of your laser show? Contact James Stewart (or his wife Julie) at Laservisuals and book on one of their laser display safety courses. This will give you an insight into how to calculate MPE's and ensure your audiences safety. You also mention scanguard, this is also marketed by Laservisuals, perhaps you could also find out what this software 'really' does. Oh, incidentally, if it's the 'Scanguard Lite' free version you're after, there's quite a few of us that are still waiting for it after many many months so I wouldn't hold your breath ;)

Again, I don't wish to sound harsh but I think you need to perhaps research things a little more. Done correctly audience scanning is one of the most beautiful and crowd pleasing effects. Done wrongly and you risk being sued to hell and back for burning the retinas of all those party guests, and that's to say nothing of all the adverse publicity that will ruin things for all of us.

Cheers

Jem

I hear what you're saying Jem and I want to be safe.

I can't afford a Laservisuals course which is why I applied for the software. I don't have an income for health reasons which is why my budgets so tight.

MPE calcs, obviously assume manual control which in turn means IDLA and Pangolin FB. At the moment, I can't afford a FB controller and software and I don't have a laptop only a fixed pc so problems there, although a long lead could overcome the pc problem but not the FB. I know there are other software options, but they still require a DAC to be purchased and to be frank, I'm not overley impressed by the ease of use, level of control or features on the cheaper / free packages (no offense meant to anyone involved in any of them). Lets face it nothing touches Pangolin software, even their consumer packages.

I would have thought in any event, with sound to light, there's no great problem for shortish events using popular lasers as many mobile disco users are using commonly purchased lasers of this power in sound to light mode day in day out with no reported adverse effects. With a well used brand therefore, you would expect any problems with their inbuilt display patterns in terms of excessive radiation to have been reported. I am aware exposure is cumulative, but equally, many are using these lasers on sound to light for 8 or 10 hours of continuous scanning, or even more. I doubt my BBQ would last more than an hour or two.

That said, if I could get my hands on a beam colliminator cheaply to make it fat beam, I would. I want to take every possible precaution I can afford to. Its not in my interest to make it dangerous as I will be in the beams also and I value my friends!

I suppose with the car port idea, projecting above the heads would be easier as the head room is about 10 feet. That said, in sound to light mode, you have no control and most lasers I've seen project patterns downwards not just straight out, so I'm not sure what the actual answer is in terms of preventing exposure.

RGB-

i am probably speaking for most people here. youre making us EXTREMELY NERVOUS!!! :rolleyes:

again, please dont think we are "coming down on you." we ARENT. it is GREAt to see that you are here asking questions BEFORE doing things. that shows great integrity and responsibility.

HOWEVER...

if you dont have the money, knowledge, means, technology, equipment or education to perform audience scanning safely, then YOU DONT PERFORM IT!!! PERIOD!!!

Sorry man. im in the USA. where the audience scanning is HIGHLY, HIGHLY controlled and regulated. there are MAYBE 3 companies TOPS that i would trust to sit through an audience scanning show with. and those companies make more money in a year than probably all of us on this forum combined. does money matter in this case? YES!! to a point.

the equipment (hardware and software) needed to PROPERLY AND SAFELY perform audience scanning is VEEEEERY expensive. the safety factors ARE NOT, i repeat, ARE NOT available and guaranteed through some fancy dancy software that someone is giving away for free. it may HELP the process, but it WILL NOT PROVIDE A SAFE LASER SHOW!!!

lasers and shows are a GREAT business to get into. however you are attempting to perform PROFESSIONAL shows, displays and effects on a hobbyist education and equipment standard. THAT IS UNACCEPTABLE!!!

the mere fact that you ask, "what is a safe power to perfrom audince scanning" eludes to the fact that you have NO idea the risks involved. a 10mW laser beam can be hazardous to the eyes under the right conditions. where as a 20W laser beam can be perfectly safe. kinda sounds ironinc doesnt it?? it poses the fact that there is a SHIT LOAD of information and calculations that need to be accomplished for EVERY SECOND that laser beam is moving. and with all due respect, that isnt going to be accomplished from a "backyard BBQ" laser show.

if you had the monetary funds and equipment to be able to perform this type of laser show than you would be doing shows for sports arenas and concerts. NOT BBQ's.

again. i repsect you coming here and asking questions before doing things. your enthusiasm speaks highly of your commitment to the love of lasers. BUT, with the love of lasers also needs to come the EDUCATION of lasers! race car drivers dont just hop in their cars and start racing. they need to learn A LOT about the vehicle they are driving. the tracks they drive on and their crews who support them.

this should be the same. lasers, when used correctly, are beautiful and safe marvels of technology. when used INCORRECTLY, they pose SERIOUOS hazards and health risks!

just because other companies do it (audeince scan) witohut any known injuries, DOES NOT MEAN NONE HAPPENED!!!

injuries may not be known for days, months or even years after.

Please be careful and get a little more education. Someone offered the idea to go to a laser safety course. thats an EXCELLENT idea!

ask more questions if need be. but please, undestand what you are getting into. its NOT just shooting a bunch of pretty little colored beams around!

-Marc

Quote:

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Originally Posted by gottaluvlasers

RGB-

i am probably speaking for most people here. youre making us EXTREMELY NERVOUS!!! :rolleyes

-Marc

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I got that vibe from him at the very first post!

Marc I know what you're saying is right and I do intend to be a cautious as possible in my approach - like I said its my eyesight as well - I'm not going to be a DJ hidden behind the projector and safe whilst everyone else fries!

That said in Europe everyone audience scans period. It doesn't mean its right, nor does it mean its always safe, however it happens as thats what most European people want - to dance in the beams. Millions of people are scanned every night of the week yet to my knowledge (quick check on google) there have only ever been 2 instances of eye damage and both of in Eastern Bloc countries. A visit to the mobile dj forums in the UK http://www.mobilediscodirectory.co.u...splay.php?f=10 and you'll find that almost all professional DJ's are using multiple projectors in every show they do - shows that will go for an entire evening 4 or more hours with no safety breaksand no MPE calcs. Yet no reported injuries. Same with most clubs who are using much more powerful projectors often 0.5 watts or more.

Here's a mobile disco vid off youtube, Australia actually but a school disco and I can count no less than 7 lasers SHINP according to the operator - 4 green, 1 double green and 2 RGY that I can see (start about 1 min 20): http://www.youtube.com/watch?v=a1vzJ...eature=related

2 x 180mw in a UK mobile disco - someone actually asked the guy about MPE earlier by the looks of it and he dismissed it by saying it was safe because of the fast stepping motors! : http://www.youtube.com/watch?v=UZAU6FVocGc

300mw green in a UK mobile disco - http://www.youtube.com/watch?v=jJFdP...eature=related

4 head 220mw SHINP style laser in UK mobile disco: http://www.youtube.com/watch?v=kegnhxQJpV0

Bearing in mind these guys will be doing Weddings, parties, childrens parties etc non stop.


Typical Nightclub (Stills Gallery + Video) - look very powerful here:

Stills: http://www.dontstayin.com/uk/sheffie.../photo-5217015

http://www.dontstayin.com/uk/sheffie.../photo-5217010

Now I'm not saying that any of these were unsafe or conversely that they were safe.

However, I think to those of you in America, its perhaps hard to appreciate just how extensive scanning is in Europe.

Believe me, I'm not saying projectors are safe, I'm well aware of the dangers, only that there is a remarkeable lack of injuries from pre-set patterns in s2l mode from the big name projector suppliers. With so many millions of people scanned every week, you'd have thought if injuries were occurring they'd have been reported, not least of because many opticians including mine, now use retinal photographs to detect changes in the back of the eye (usually they're looking for macular degeneration) - however its something that I would expect show up burn injuries. I was recently assessed for laser eye surgery and had retinal photos at the hospital, so I know mine are OK.

That said, as I said above, I want to be as safe as I possibly can. Its not about the total elimination of all risk, because we all know there's only one way to avoid that and thats leave the projector switched off, but I want to be responsible and not just take the same gamble as everyone else does despite no apparent injuries and instead try my best to elimate the risk as much as is possible. However, with sound to light thats very hard as you don't know what pattern's coming next or its duration or speed or dierction, so to a certain extent, you can only rely on the fatc that with a widely used projector, there have been no problems in S2L mode.

Like I also, say, I could mount a projector overhead, but its almost certain that with sound to light, some patterns would project down anyway.

With ILDA, its different as its possible to calulate I know, but I don't have FB and I don't totally see your objection to software. The software should be programmed with the same equations and parameters as a manual calculation surely, the only difference being that once the parameters are entered, the computer does the calculation for you thus avoiding human error. So I can't immediately see why good software should be any less accurate provided its used properly.

However, I welcome any safety advice you can give to try to ensure I can keep things safe, and I'm willing to do everything I can within financial constraints to make things safe, - if you know of any cheap colliminators that can be easily fastened on the fron to make a projector fat beam, I'm on it. However simply not audience scanning isn't an option.