50mW are safe for... ?

[Sourcegeek]

Hi!
I'm making a cheap DIY hard drive projector with help of a red 5mW laser...
The projector is almost ready, so i was finding lasers for making it better and i found one Green 50mW laser on FocalPrice, so...
This laser is safe for doing people scanning? I think the not-safe lasers are >100mW, but i'm not sure =/

Thanks

 

[aryntha]

It's not as simple as that. You have to calculate sweep rate, NOHD and beam size, divergence; a whole lot of things. Raw source power isn't enough to determine if it's safe.

I'd also be worried about the duty cycle on a 532 from Focalprice in a projector.

 

[Sourcegeek]

So.. In normal conditions and caracteristics (sweep rate, beam size, etc), is it dangerous? I just want an aproximate

 

[Bionic-Badger]

There are no "normal conditions" for scanners because they're used in completely different situations all the time. Until you know exactly what conditions you'll be working in, anything above 5mW will be unsafe--especially for audience scanning.

 

[Sourcegeek]

And what conditions i need to know and how I can determine they? Sorry my ignorance

 

[Bionic-Badger]

Read through the various pages at sites like these.

 

[Sourcegeek]

Thanks for the link.. I see one of the principal problem is the dot diameter..
I don't have too much money, so the laser i'll get from FocalPrice is too cheap.. I was finding any collimator and there is not on FocalPrice or DealExtreme.. I want to do one homemade, but I don't have concave or convex lens =/
Can i do a collimator with plastic or any other thing?

Thanks

 

[chipdouglas]

crowd scanning is hard enough for the pros. it really can be quite dangerous. i know it is not as cool but if you have the beams a foot over everybodies heads, the crowd can still feel like they are a part of the show. i know from experiece being in that type of crowd.

michael.

 

[Sourcegeek]

Yeah, i was thinking on that idea..
Another idea was 'skyscanning' with the 50mW green laser and people scanning with a little 5mW red laser.
But, before doing it, i want to know if i can make a collimator with plastic or any other thing...
I disarmed a DVD player, and i found a lens with a little diffraction grating: the laser get divided into 5 beams. The one at the center is more powerful than the others, and the beams at the sides are more weak, so, I was thinking.. This can work as collimator aiming the last beams (the weak ones) at the galvos?

 

[Bluefan]

Diffraction gratings don't work as a collimator, but it can work as an attenuator if that's what you mean.