I want to do a presentation 200mw

[makeitnew]

sorry for the long post. I need details in here so I don't put anybody in danger.:thanks: also this is going to be a bit taboo, so please try to be nice.

I'm trying to find an acceptable power range that people can view the beam and dot without glasses, and still pop stuff and light matches.

Lets assume the laser if bolted down, and there will only be black matte balloons, and all material the beam hits are non fluorescing materials excpet for my stopping plate of white, which will be enclosed in a box.

Now what is the max power that is safe to view a 405nm or 445nm without glasses and at what distance.

I can't seem to find anything except. just wear glasses for everything. but sometimes like this, it's just not addressable. we don't have money for a bunch of glasses. So if we make it the laser setup safe enough to be around without hurting anybody. I see no reason to make them wear glasses.

When I was in elementary school a guy came in with a laser. It was green visible and he popped a balloons and such. None of us every had glasses, but he was mounted and setup with his laser disappearing into a box

If you know of a power level for beam and dot without damaging ones eyes I'd appreciate a link.

I was thinking my china 200mw 405nm from elecday mounted in a clamp would do the trick, but that might be to bright.


Could I point at the sky instead? is it safe to few the beam of a 200m 405nm. That dot can be tricky, so I know its best to shield, but if there is a way i'd like to know


:thanks:

 

[Quetzal]

If you'd clarify as to who your audience is and under what capacity you'd be presenting, it would help things a lot, and possibly find a solution that makes everybody happy.

-------NOW FOR THE GENERIC PART----------------

Okay, you seem to be a bit confused about laser power outputs, which is okay, but this is important stuff to know.

A "burning" laser is anything more than ~100mW.

It really isn't safe to be near a burning laser without goggles. I know what you said, about it being bolted down, etc. , but you never know what might happen. You will also be in deep sh*t if anyone gets hurt.

That guy that came to your school: he was an idiot. Especially around little kids, don't mess with lasers.

Think about it like this: A laser fires a collimated photon stream. Photons are like unimaginably small BB's. Spread out, they're not a problem. Condense them like a laser does, and you've got yourself uncountable numbers of tiny projectiles that like very much to bounce off of other tings, retaining much of their original power.
I'm gonna put this very plainly. Lasers are not safe. They have an inherent danger, much like a BB gun. When handled properly, the risk can be mitigated almost to the point of marginalization. However, even the slightest blunder on your part could end up maiming somebody for life. Keep that in mind.

Safety glasses are a non issue. It's like saying "let's go for a car ride, but I don't have enough seat belts for everyone." Yes, nothing might happen. But yes, you could also get in a car wreck that will badly hurt those without seat belts.

Okay, now that I've gotten the safety part covered, we can talk about your beam. You seem to have a 405nm laser. 405 is TERRIBLE for beam visibility. If you want people to see it, try 445 nm. MUCH better. Also, you may want to invest in a fog machine. It greatly helps with seeing the beam.

Here's an idea:

you could put the whole setup in a room, and only allow a few people in at a time, and have them wear glasses. That way, you'd only need maybe 5 pairs of glasses (plus some for yourself and any assistants)

Point at the sky? Are you serious? If a plane flies overhead, since your setup is bolted down and enclosed in a box, you may be too late to prevent yourself from blinding the pilot.


And if I sound like I'm trolling, that's not my intention. I just want to keep everybody out of trouble, and still able to see.

 

[makeitnew]

thank you that was exactly what i needed to know. They sky question was just for a concept. I'd never risk pilot safety. It sounds like I just shouldn't do it at all and the guy who came to my school was definitely an idiot. over the past few days I finally found something that said 200mw is not safe to view the beam directly, and everything in safe ranges wouldn't do anything impressive.

 

[Quetzal]

Glad I could help