I'm here at the studio of LSDI about to talk about Pangolins new safety scan lenses for
audience scanning.
Now, Greg and I have done audience scanning measurements over many years.
And we have documented within articles that Greg has written, within I've written, within
article and safety thesis that John O'Hagan has written.
About audience scanning and how it can be dangerous if not done correctly.
Basically what it comes down to is that the measurements that we have done over the years,
that we've repeated again today, prove, that if you want to do audience scanning as the
laser beam comes straight out of the laser, you're basically stuck with about 10 milliwatts
of light.
And obviously that's not very visually effective.
But that's safe.
So the question is, how to get higher brightness.
A more effective show at the same time as safety.
The conclusion that we came up with an article, that Greg Mackov wrote called art versus science,
and in the separate article that I wrote years later, that appeared in the laserist.
About how to do audience scanning safely.
And then in a complete safety thesis that John O'Hagan wrote, was that the only way
to get audience scanning to be safe, is to increase the divergence.
The problem is, that if you increase the divergence over the entire scan field, it makes the lasers
appear, like that they're being projected in clouds.
Like maybe you're in an airplane, looking down the clouds or something like that.
Makes it look very cottony or cloudy.
And that's really takes away from the main intention and the effect, that we as laserists
want to accomplish.
So earlier this year, we came out with, what we call safety scan lens.
It comes in this nice little kit like this.
And we have a complete set of lenses.
Six to be exact.
And what this is, is it's a half moon shaped lens.
Where the lasers, as they're being projected, will project above the lens and not have any
effect at all.
So they will be at zero divergence increase above the head.
So it'll be the maximum effectiveness the typical laser show that you would normally see.
Whereas down below the lens, the divergence is increased, to increase audience safety.
Now an interesting thing happens, when you project the lasers through this lens, it increases
the divergence, but only within the audience area.
And so the safety is increased within the audience area.
And although the beams are more cloudy or fuzzy or out of focus, down within the audience,
the fact that the beams are still have low divergence above your head, as you're watching
the laser show, you really don't even consciously realize this and recognize this.
So what we're going to be talking about today is, how to install this on a projector.
What this does.
The various aspects of how it will affect the projection.
And how to adjust this for for maximum effectiveness.
And we'll also be showing you a laser show, with these lens and without.
So that you'll be able to see the difference and see exactly, what a safe show looks like.
What an unsafe show looks like and so forth.
Basically what we'll do, is we will project an audience scanning show at 10 milliwatts.
Which is the safe level without the lens.
And then we will increase the the divergence with the lens.
And then you'll be able to see that you get a dramatically better effect with the lens.
So what we have in this kit are six different lenses.
Each lens increases divergence a little bit more.
And these are numbers, one through six.
A number one lens is the thinnest.
And it increases the divergence just a little bit.
It's mostly used for big outdoor shows.
Where you don't really need too much of a divergence increase or where the laser is
very far from the audience.
And we have a number six.
Which increases the divergence quite a bit.
It's the maximum that we have in stock here at Pangolin.
And so it's a thicker lens because it needs to have more material to increase the divergence
more.
So what we've done is, we've put them all in this nice carrying case.
And this foam is specially formulated foam, that does not harm the lens.
It doesn't out gas.
And it just provides a nice carrying case.
And this is especially handy, when you're doing touring and things like that.
Where each next venue that you go to, may require a different level of divergence to
attain safety. So it makes it a very handy package.
One of the things that we've done today, we've used both a KVANT laser.
Two separate KVANT lasers in fact.
And we've used an RGB laser projector.
One of the things we found, is that there are some variations from laser to laser.
In terms of the beam divergence that comes out of the laser.
Because what these lenses do, is they increase the divergence that the laser already has.
So if the laser has lower divergence, naturally you might need a greater increase in divergence.
And therefore you might need an actually even stronger lens.
But this table can serve as a starting point.
Well this will get you in the ballpark.
We would always recommend that you do measurements to make sure that you have the right lens
for the job.
But at least this table will kind of get you in the ballpark.
So that you choose the right lens for the job.
So let me give you an example of what we found here.
As I say, earlier today we've done some measurements.
We have a Thor labs, high power power meter here.
We also have a very special irradiance meter from international light.
And we've done these measurements today, confirming what we already knew.
Which is that if you don't use a lens, if you do not increase the divergence of the
laser projector, you can only get away with about 10 milliwatts coming out of the laser
projector.
But using this RGB laser projector as an example.
If we use our number one lens, we can increase the laser power to a whopping 15 milliwatts.
But going up the scale to our number six lens, we can use the same RGB projector at five
meters from the audience at a power level of 210 milliwatts.
So 20 times more power than we could completely without a lens.
Now if we move this projector 10 meters away from the audience, which is at least a more
realistic scenario, bigger room so forth.
Again with no lens at all, it's 10 milliwatts.
But using up to our number six lens, you can operate that rgb laser projector at 870 milliwatts.
Now it's important to notice that what we're talking about is this is the power level,
the actual power that you would measure with a power meter.
But actually when projected down into the audience, this is a two watt RGB laser projector.
So what we could have is, we have the entire two watts at low divergence above the heads
of the audience.
Lowering the power to 870 milliwatts with our number six lens down in the audience.
And how we would do that is with Pangolins beam attenuation map technology.
So basically in many cases, you would be using both the beam attenuation map to reduce the
power within the audience.
And also a lens to increase the divergence within the audience.
And in most cases this would not even be noticeable to the audience.
That there's lower power.
Because the lasers are projecting at a downward angle through the fog with a forward scattering
action, that makes the beam look actually even brighter.
Now as I place the lens into the beam, one of the things that you notice is, that as
I move it upward, of course it increases the divergence.
That's what it's supposed to do.
As I was saying in an earlier slide, I like to choose a pattern, that has a central spar in it.
So that as we move the lens, left to right, we can orient this to make the center exactly
perfect.
Now one of the things that this lens does, in addition to increasing the divergence,
is it also increases the scan angle of the image.
Now when we sold these lenses to our first few clients and they noticed this in the projected
image, they said hey this thing is increasing the scan angle of the projected image too.
That's not right or that's not desirable or that'll never work.
The thing is, is that as you're projecting this onto a surface, most definitely you see
this wider scan angle.
But in the projected imagery, in the audience scanning, you really can't tell that.
And we'll see a real audience scanning laser show here in a second.
You'll see that, even though the divergences increase and the reality is, that the scan
angle is also increased, it's just not noticeable in normal audience scanning imagery.
So the width increase, really is not noticeable in normal audience scanning.
To talk about this a little bit more, I could say that at our trade show booth in Prolight
and Sound, where we had six laser projectors with six of these lenses on it.
Numerous experienced professional lasers came by our booth.
People that did Muse world tour and and some of the top names in the entire industry.
We're talking about Alberto Kellner, Hugo Bunk, Maurice Wartell came by to see the show.
And before they saw the show, we didn't prompt them in any way.
We just said let us know what you think of this laser show.
We'd like to hear what you think afterwards.
To see if they would detect anything objectionable.
And at the end of the show, we'd ask them.
Did you notice anything?
Was there anything strange or unusual about the show?
And in most cases they said no.
They didn't notice anything.
When they did say that they noticed something, they only said that they noticed that the
show was more pleasant.
So they didn't really say, oh there's some sort of objectionable thing going on here.
This is not a laser show.
It was all very positive.
So there's three important adjustments, with respect to this lens, and how it works.
One of the adjustments is obvious.
It's upward and downward.
As you move the lens upward into the projected image, it will increase the divergence in
the low part of this scan field.
Where the lens is in place.
So this is a pretty obvious, what we're doing here.
Is just up and down.
What might not be so obvious is left to right.
As you move the lens left to right, what happens is, the entire image will shift somewhat left
to right.
So what I do, is I use a test pattern that has a clear central line in it, so that as
I'm moving the lens left to right, I just line up that central line.
And that lets me know that I have the lens in place.
What's not so obvious is swinging the lens this way.
This tilt effect here.
As you tilt the lens, if the lens isn't precisely in a correct orientation, horizontally.
It's like skipping stones off the water.
If the lens is tipped up too much this way, we get a ghost word.
An upward facing ghost image.
If the lens is tipped too far downward like that, you get kind of a downward facing ghost image.
So it's only when the lens is precisely in the central position here.
Oriented this way, angularly, that you get perfect images out of this.
Now what we've done with these lenses is, we've created a lens mount that works perfectly
on KVANT projectors.
If you don't have a KVANT projector that's okay, because it just uses two little screws.
And it's pretty easy to mount two flat screws to your projector which you can then attach
this bracket to.
But what this is, is it allows the lens to slide upward and downward into the scan field.
And as you see, we also have this degree here, where we can control the angle of the lens.
And so once we get this directly in place, we just tighten up the screws.
And then that will hold the lens and the precise orientation that we want.
Okay you've seen what laser shows look like at higher power coming directly out of the
laser projector with the safety scan lens.
Now what we've done is completely removed the safety scan lens, and we've adjusted the
laser projector power to roughly 10 milliwatts.
We're doing a safety measurement here with the meter to get to 10 milliwatts per square centimeter.
So now you'll get to see what the laser show looks like with no safety scan lens involved.
And just the direct beam from the laser projector.