Incidentally... those lasers can do the SAME thing to your eyes.
A "Class IIIa" laser pointer is 5mW or less. But that's the TOTAL output of the laser. It turns out most lasers put out a harmonic which is double the wavelength of the laser itself. So a 532nm green laser is also creating a 1064nm harmonic --that's in the infrared spectrum and is not visible. However... just because it's not visible doesn't mean it isn't dangerous. So it's important that the harmonic be filtered OR that the total output of the laser is weaker than 5mW.
And yet... this still doesn't make it "safe". What it means is that it's weak enough that the blink reflex of the human eye is likely to be able to react, close your eyelids, and turn away *before* "permanent" damage can occur.
The brighter "Class IIIb" and higher lasers are classified as such because it turns out they are strong enough to cause permanent damage in less time than you could possibly "blink" to close your eyes and turn away. These are dangerous lasers. UNDER NO CIRCUMSTANCES should they EVER be allowed to point into the crowd - no exceptions. They really need to be aimed high above ... and even then care has to be taken to ensure that there can be no flective surfaces that would bounce them down. Those shiney mylar baloons... that would be a problem.
There are no pain recepters in the back of your eye. The damage can take 24 to 48 hours before it sets in. You could get hit with a laser in the eye, think you are ok, and then wake up 24 to 48 hours later and realize you can't see.
All I can say after watching the video is... better the camera got fried then the person's eyes. This club should not be operating those lasers in that manner.
Tim Campbell
5D III, 5D IV, 60Da
