100 mW dangerous?

[Dj-IceLava]

i was thinking of buying a 100 mW laser pen from eBay(it's not a scam) has real power of 100 mW and an IR filter, i'm going to make a small show to start with, (just diffraction gratings, mirrors, and stuff,) i'm thinking will it be dangerous to the audience that are dancing on the floor? :-?

 

[pseudonomen137]

i was thinking of buying a 100  mW laser pen from eBay(it's not a scam) has real power of 100 mW and an IR filter, i'm going to make a small show to start with, (just diffraction gratings, mirrors, and stuff,) i'm thinking will it be dangerous to the audience that are dancing on the floor? :-?

If its being rapidly scanned it won't be much of an issue. The 100mW beam, stationary at any one point, is more than enough to cause permanent damage though. Its not particularly likely, but the risk is still there and its not a smart gamble to take.

Also, keep in mind that if you're in the US the lasershow will already be illegal to use in a club unless its <5mW. Crowd scanning is gunna be like a sceond offense - the FDA is VERY strict on projecting into an audience, and for the most part, its banned in the US.

 

[Tallaxo]

Well that is a very subjective question. if a direct beam was to flash into someones eyes, then yes it could cause damage. However if the beam is split up using a diffraction grating or scanned with some kind of mirror and motor system so the beam is in many places at once, then it would be "safer". That is not to say it would be safe though.

A lot of factors need to be taken into consideration such as actual beam strength, laser scanning speed, distance from crowd, etc. so there is no easy answer to that.

Your main concern over using a pen laser of that power as a laser show , would be the duty cycle, you really would not want it to be on for more than about a minute at a time, with 2 or 3 minute cooldown, if you plan on using it all night.

Hope this helps somewhat.

Jase

 

[SenKat]

Another thing to consider is this - when I see a statement start out with, I am thinking of buying a green laser from ebay, and it is not a scam - alarm bells ring LOUD for me - as I am certain they do for others as well. Be careful, and make sure you do your research on both the device, and the company before you purchase.

G !

 

[Things]

it also depends how much fog you have, if any, more fog would limit the amount of light, and the laser beam in the end will be alot dimmer

 

[Benm]

Lasers for lasershows can have considerable power (into the watts or even tens of watts range), but in commercial units some safeties are provided.

One thing is a mechanism that blocks the laser light when the scanning mechanism fails for any reason, to prevent a steady beam hitting a single spot.

Also, such lasers combined with their optics usually have rather poor divergence, limiting the risk at greater distances from the device. For the optical effect this doesn't matter very much, but safetywise it does.

 

[Things]

yes benm, laser shows can even sometimes be in 100's of watts if it's for an outside thing, but they have TONS of safety features, like you said, it can block the beam if something goes wrong, they have special keys to operate it, and generally you can't point it into the crowd if it's too high powered. 100mw might be ok for pointing into the crowd through fog, generally because the fog limits the amount of light getting through, and when the laser beams hit the crowd, they may only be 10mw

 

[pseudonomen137]

The fog scatters the light some, but I don't think it really attenuates the beam that much. Not enough that you can count on it for saftey at the very least. Otherwise you'd expect the spot to get significatly dimmer over distance - which it doesn't.

And yeah, in US crowd scanning is next to impossible to do legally. I think GLL's lasershow company has applied 10 times or something and only gotten cleared twice.

 

[Things]

some fog is slightly brown, and when i'm using my laser show, the dot at the end is much dimmer

 

[Phazonx]

well, not an expert on lasers or anything.

But it would seem to be totally safe if you place the beam path 6 feet high.

so no one gets lasers in there eyes.

 

[Things]

yeah! but the only concern is visibility?

 

[shiftline]

How about a 50 mw laser. i have been to out side events, where the laser ht the crow d mainly reflected offf a mirror ball...

my 50mW should be safe for Halloween parties and such i hope lol.

 

[Things]

ya just try to keep it out of peoples eyes! is it green or red?

 

[SenKat]

well, not an expert on lasers or anything.

But it would seem to be totally safe if you place the beam path 6 feet high.

so no one gets lasers in there eyes.

Hmmmm - I am 6'5" tall - with a HUGE cranium ! (LOL !!<----have my own sattelites, I do !)

I would get smacked square in the eye sockets if you beamed it at 6' !!!!!
(uhm...assuming I am not in my wheelchair, that is )

 

[philguy]

Would it actually be safer to use sth. like a 100W incandescent light bulb and focus that/send it through a small hole? As that way, the "beam" is no longer coherent and if it hits the eye, the focused spot on the retina will not have such a high power per area?

Obviously, an incandescent kills it for fast modulation and "lasery" behavior of the beam.

 

[Things]

well a incandescent bulb can't be colluminated, so the dot would do like any regular light, and spread out really quickly! yes it may be safer, but you can't really get a "lasery" effect without a laser!