10 questions

[pxshock]

i am trying to find the correct laser for my needs

sorry for all the questions, just trying to be safe than sorry.

1. for a rave would a 55mW pen green laser be suitable? what mW would be suitable?

2. more mW, more burning power, plus more brighter, does this burning power result from the intensity/brightness of the green laser or the increase in infrared that the crystal could not completely convert to green?

i plan to have spinning motors, and some diffraction gratings, and crystal ball effect, one man laser show basically, i plan to have the beam above the crowds heads.

3. if a person jumps into the beam and catches a glimpse of a moving beam more than 8 feet away will their eyes go bad, or hurt? what will happen? i see many videos with lasers passing into the crowd, but no one complains, i also heard of lasers blinding pilots, even though they are different mW lasers, the rule of thumb is always wear safety glasses when working with any laser over 5mW...does this only apply to a certain distance? so what is safe and not? (this confuses me so so so very much)

4. all high powered lasers(anything above 5mW) can burn, but the burning intensity goes less with the distance, so does that mean my audience will be safe in a 8 feet distance.

5. will i as the operator have to wear eye protection? or anything else?

6 i plan to buy a pen laser, im not sure yet, im very much open to suggestions at the moment, but will you advise me to but an extra infra red shield to put in front of the beam?

i wish to have a laser show of the brightness of the green lasers in

youtube.com/watch?v=TRzs44xFvqw

its obviously more than a 5mW laser being used.

7. how much mW would you think the green lasers are?

8. at times the beam shoots at the crowd, is that safe? or because it passes over the eyes so fast there is no effect?

9. does any one know where to get a long sheet of a diffraction grate so i can cut out the size that i want? the starburst gratings are too small to mount on a spinning motor to have the laser light pass through.

i still want to have a bright light laser show, what is the max and minimum mW laser you will recommend for this purpose.

ive been reading various forums and threads, some answers to questions like mine vary so i get confused

im sorry for all the questions, i am new as u can tell (maybe one day ill be answering very questions like these )

I dont want to risk anyones eyes or body during the laser show, safety is my absolute number one concern, and to have a good bright laser show is next.

any help would be appreciated

thanks in advance.

 

[Switch]

1) 55mW of green would be very visible in all the smoke.
2) burning power is a result of energy density (power/surface). Power is measured in Watts(or mW), whether it's IR or green, if you have more mW, you have more burning power.A good quality green laser will have little IR emission and more green emission.
3)Catching a beam in the eye is not good, especially from a home made spyrograph type scanner(since they're slower than a double galvo scanner).8 feet or point blank, or more, it really depends on energy density again.Since the laser is diverging,(the dot is getting bigger at distance, the power/surface will also decrease.How much it decreases depends on divergence.So I can't really give you a "safe distance" or "safe power/distance" rating.
4)think it's already answered.
5)Not if you're careful and you don't drink.
6)A pen laser won't offer you the duty cycle needed for a laser show, additional cooling will be necessary
7)I would say those lasers are at least 50mW or more, but I'm not really sure.
8)It should be safe for the reason that you stated.
9)I don't know this one. :-/

Even a 30 or a 20 mW would be really bright if there's lots of smoke in the room, don't worry.But for the way you intend on using it , I really wouldn't recommend 8 feet if there's any chance someone will catch it in the eye.Maybe a decent distance of about 10 meters and if you mess with the divergence a little(make it worse, but it will still be good for a beam show) and make sure the whole thing's stable and high enough for anyone to get hit.Better not risk those things. Or you could always use a 5mW, won't be as bright , but still pretty visible.

Just out of curiosity, what country are you from? :-/

 

[pxshock]

Just out of curiosity, what country are you from? :-/

ha its actually my bad typing and not typing as fast as i think that gave me away or not ;D

hey thankx for the reply...

i really appreciate it, im from Jamaica.... out here rave/trance isnt very big, out here there arnt many raves, if at all any, the so called raves is run by some goths..(ya fun), and obviously play rock music and have no preety lighting and/or effects, the clubs out here stick to the flashing spotlights, so i really dont have that chance of being in a laser club enviroment, what i know is off youtube and the 5 laser forums such as this one, and most threads are waay past the basics...and its hard to zero in on posts that answer my questions, google helps a little...

so basically, its summer, and im trying to hold a nice glow sticking event. with some laser effects like whats on y0utube.

well for the smoke, i considered it, but didnt really bother with it because to rent a smoke machine is about 200us a night(the smaller ones, and they sell it online for about 60us( but shiping it in its pretty much gona be the same 200us)...boi this is the country i live in love it so much (sarcasm) ), i wasnt planning on having any, but im reconsidering.

im not planning to have the beam static at all, moving always, the only time it will crowd scan is when im doin a spot light effect or crystal ball effect. and those will be fast so that should be fine.

btw i found a site that kinda explains things,
laserist.org/Laserist/showbasics_7.html

when you say extra cooling? does mean like a fan, or do you mean some other form of rapid cooling?

just for safety reasons, and because i dont know much about my first laser, and after seeing some tables like
"Comparison Chart For Burning and Power"
dragonlasers.com/catalog/Viper-Series-price0-p-1-c-262.html
i will be sticking with the 55mW

this is probably not the best place to discuss this, but after looking thru numerous threads on different forums i mite add, seems like optotronics and dragonlasers are a good bet....agree? novolasers and laserglow seem out of my price league.. :-[

still quite interested in the diffraction gratings (make a silly move and called shops out here people where like "huh??!?!") any one know of any places?

 

[Switch]

Nah it wasn't your typing, it was that the youtube video you posted was from a club in Bucharest, which is the capital of my country.I was thinking that maybe you're from here too. Unfortunately you're not gonna be able to DIY scanners like in that video very easily.Those don't use ordinary spinning motors, they use galvanometers or stepper motors.

Some sort of heatsink and a fan would help, but a penlaser is still not really apropriate for a laser show.It would be better if the diode was attached directly to the heatsink, and it uses AAA batteries which are a very bad source of power for a beam show module. :-/(though you can always make it run off of an external PSU pretty easily.)

There should also be some cheap fog machines on some site(that someone will hopefully eventually post since I can't remember right now) that you can get for ~$20 shipped if I remember correctly.But I wasn't talking about that anyway.....there should be a ton of cigarette smoke at any rave anyway ;D that'll do.

As for the diffraction gratings , there are some big sheets but those only generate one line, I don't know of any big piece of film that you can cut up that generates cool shapes and dot matrices. :-/