No H&S restrictions on Audience scanning?

[buffo]

Personally, I wouldn't want to be facing the lens of one of those either. If it's capable of producing mid-air beams like a laser does, it probably throws out similar power densities as well (and thus can exceed MPE).

But it's not a mono-chromatic, spacially-coherent beam. Thus it will not be focused to a diffraction-limited spot on the back of your retina, and it won't reach power densities of hundreds of thousands of watts. The beam from a laser will.

Remember: You can focus a 500 mw beam from a laser down to a microscopic point using just a tiny lens and burn wood with the beam, but try the same trick with a 2 inch diameter magnifying glass using the sun as a light source and you'll be hard pressed to smoke anything. Why? Because the sun is not mono-chromatic. The spot the magnifying glass makes is HUGE compared to the microscopic spot from a focused laser beam.

I don't know if anyone ever calculated the power density for a 2kW or even 5kW HMI profile theatre spot, but the beams on those are pretty damn narrow and people stare into those all the time.

Agreed. They're damn bright. But it's not the raw power that's important. It's the power density (or irradiance, if you will) at the retina that counts. Broad-spectrum light does not focus well. But mono-chromatic light focuses *very* well.

You can do more damage to your eyes with a 1 watt laser than you could with a 5000 watt light bulb, simply because the lens in your eye will concentrate that 1 watt laser down to a diffraction-limited spot, increasing the power density tremendously. (We're talking 7 to 9 orders of magnitude here, even though the human eye is far from being a perfect lens.) You can't do that with the broad-spectrum light you get from a light bulb.

Adam

[VJ AIWAZ]

i actually have a 15k that i want to sell if you want to try it for real ill let it go for $13000 i paid $18500 for it plus $2000 for the
road case

[Jem]

i actually have a 15k that i want to sell if you want to try it for real ill let it go for $13000 i paid $18500 for it plus $2000 for the
road case

I would love to get my hands on one of those, but it's waaaaaaaay beyond budget

Perhaps when the projector gets down to the price of the road case

Jem

[smokeAndMirrors]

Personally, I wouldn't want to be facing the lens of one of those either. If it's capable of producing mid-air beams like a laser does, it probably throws out similar power densities as well (and thus can exceed MPE).

Just to hammer home buffo's point: it's not just the fact that energy from a light bulb is smeared over a wide frequency range that makes it weaker (because the focal point is wavelength-dependent). Another big deal is that a laser's coherent radiation is in phase as it leaves the emitter, so it makes one big wavefront with little or no destructive interference, therefore energy transfer is large and varies slowly; whereas thermal radiation has random phase and therefore delivers fluctuating energy over arbitrarily small periods of time.

[VJ AIWAZ]

some shots of my 15k

[Jem]

Nice

I like the Generator too. I have one of the smaller Honda generators, it probably generates better power than the mains.

Jem

[mccarrot]

"

No Health and safety restrictions when using video projector for crowd scanning effects.


Totally safe to the human eye."

If you put lets say a -5 lens in front of the aperture to increase the divergence to about 10mRad your laser will also be totaly safe...

thats similar when you make beams with a Projector the divrigence will be really worse, and will only have a nice effect on a short distance.

[VJ AIWAZ]

yea i have one of the smaller 2000 units as well but that will run a 10k max with the 15k being 220v single phase at about 10amps we need the 3000watt unit and a step up converter for 110 to 220

i run it off the generator when i do guerilla projections for marketing firms

[instinct]

I've got 3 projectors.. my brightest one does about 4.5k Lumens.. I've always wanted to make a video file to simulate a laser projector and use it with fog to see how it looks.. Anyone know of a free one?

[mliptack]

2gs on a road case... .... you spent WAY too much on that case...