Photon Fix - 1 watt of green - Interesting Safety Issue

[White-Light]

Thought I'd post this:

http://vimeo.com/7255957

That's 1 watt of green into the crowd from less than 10 feet to the nearest member.

On the face of it this seems highly dangerous, however, the camera suffered very little smear, there's no camera damage.

Could this be an example of sheer scanner speed rendering what might be considered unsafe, safe? From the side on, I couldn't detect any attenuation mapping. The laser I found out btw way was a Nemesis 1 watt from Laserelectronics ltd with I believe 15K scanners and was under Zion control.

[White-Light]

Link now added.

[Laser Ben]

*Searches for "MPE"

[Xytrell]

I couldn't detect any attenuation mapping.

Couldn't that mean the attenuation mapping was done well?

[dave]

So, what was the divergence of the laser?

[White-Light]

*Searches for "MPE"

I'm quite well aware of MPE. This was at a highly respected nightclub (not the one I usually post about) and I'd find it hard to believe it wasn't done without a licence so I wondered if they some how managed to get emissions within the 10x Standard.

At this event, the only point causing smear on the camera is the aperture on the laser irrespective of whether the beams are towards the camera or not. Not of the beams are causing smear on the CMOS when pointing at the camera. Not a definitive check, but always a good indicator as you can get pixel damage and smear within MPE limits.

Couldn't that mean the attenuation mapping was done well?

It could but I can't spot it from the side on view. Usually they say you can't spot attenuation mapping because the laser gets apparently brighter as it comes down onto the same plane as you. Viewed from side on, that shouldn't happen obviously.

So, what was the divergence of the laser?

Unknown but the beams looked very thin crisp and tight in the air when part of a "lined" fan. I will say the pattern on the rear wall looked quite thick though although I couldn't see any lens on the laser itself and the crispness of the beams would seem to bely this.

Here's a screen capture from the back wall - distance maybe 50 feet - must admit looks fat even though air borne beams look very tight???

[FourDee]

I'm quite well aware of MPE. This was at a highly respected nightclub (not the one I usually post about) and I'd find it hard to believe it wasn't done without a licence so I wondered if they some how managed to get emissions within the 10x Standard.

If you are well aware of MPE, then you should know that 'shear scan speed' as you call it has close to no influence on exposure

[buffo]

If you are well aware of MPE, then you should know that 'shear scan speed' as you call it has close to no influence on exposure

I agree. Scanner speed has a trivial effect on the overall MPE. More to the point, however, is this piece of information:

The laser I found out btw way was a Nemesis 1 watt from Laserelectronics ltd with I believe 15K scanners

15Kpps is pretty slow for a set of scanners, considering the state of the art these days. So it clearly wasn't a case of "sheer scanner speed rendering what might be considered unsafe, safe".

Either the divergence of the laser (which does appear to be significant, judging by the picture posted above) was enough by itself, or there was an undetected attenuation map which reduced the power further, or the show was in fact unsafe but for whatever reason you did not suffer an aversion response.

Adam

[sbk]

You can see on the video that there was permanently a great quantity of thick smoke in the few first feets right after the aperture of the laser projector, which may influence the remaining power after travelling such that smoke!

[White-Light]

15Kpps is pretty slow for a set of scanners, considering the state of the art these days. So it clearly wasn't a case of "sheer scanner speed rendering what might be considered unsafe, safe".

Either the divergence of the laser (which does appear to be significant, judging by the picture posted above) was enough by itself, or there was an undetected attenuation map which reduced the power further, or the show was in fact unsafe but for whatever reason you did not suffer an aversion response.

Adam

I know Adam that scan speed has to be offset against increased repeats so I agree it has in principal a trivial effect except. However, it seems something was rendering the effects comfortable. Maybe it was the fact that many were tunnels with the tunnel expanding quickly so the actual edge of the tunnel was only passing over the eye very briefly as the tunnel spread out.

I also agree the divergence as seen on the rear wall looks significant. however the lines in the beam looked almost pencil and some of the crispest I'v ever seen. I'm at a loss to explain those 2 conflicting facts.