Laser power question...

[leztid]

We are doing Peter Pan the Musical and are going to use a Green laser as a Tinkerbell effect.

I don't know much about lasers and their different power levels. We've done some tests and think that 150mW will be bright enough to achieve the desired effect.

So my question,

At about 50-75 feet, what is the maximum power of laser we would use without hurting the performers eyes?

Also, Would it be possible to gel the laser to change its color slightly?

 

[Les]

There really is no "safe" exposure when it comes to lasers. Theoretically, even a 5 mW can do damage, and they have.

I do also feel obligated to tell you that 5mW is the legal limit without a variance, so your 150mW laser is probably non-compliant.

That said, Flying by Foy offers a 3mW green laser on a stand to play Tink. Care must be taken to not hit performers' eyes with any laser system.


Sent from my iPhone using Tapatalk

 

[FMEng]

One problem with lasers is that a reflection can be just as dangerous as the direct beam. You might be thinking you are careful enough by directing the beam away from eyes and the beam hits something just right and reflects into an eye with ample strength to do harm. I'm no expert, but from what I have read, I would not go beyond 5 mW, which is a class 3R. 5 mW is the limit for a device sold as a pointer in the US. Even at that level, it is hazardous and not a toy. Higher power just isn't worth the risks and liabilities. Also note that possession, of any laser, by a minor is illegal in some states. Here are some references.
http://www.lasersafetyfacts.com/

http://www.laserpointersafety.com/rules-general/uslaws/uslaws.html

 

[robartsd]

Also, Would it be possible to gel the laser to change its color slightly?

A laser outputs a specific frequency of light. Color filter media works by reducing unwanted fequencies from broad spectrum sorces. Putting a filter in front of a laser should not change its color at all.

 

[WindWorks Design]

Lasers are mono-chromatic. That means they emit light only in a very, very, very narrow spectrum of color. So no, a color filter will not change the color unless it is (unlikely) a multi-line laser. And from a previous entry in this thread, 5mW is perfectly legal, so the 3mW system from Foy requires no variance. BTW: there is an exception to the 5mW rule. If the laser beam is fat enough so the maximum power a fully dilated pupil of the eye can absorb is <5mW, then you can have a much more powerful beam from the laser. Some projectors available call this "fat beam" and other "no variance required" type nomenclature.