External Lens Projector Mount?

[JStewart]

Has anyone come up with a neat solution to mounting Pangolin's external SafetyScan lenses?

Kvant have a good device which screws onto their existing projector mounting points used for the aperture protector/blanking plate. The holder gives good and precise alignment of the lens, and at the moment is the only laser manufacturer that I’m aware of that offers any solution.

But I was wondering if there was a more universal solution for other projectors? – As I’ve had to work on some projects where double folded gaffer tape and foil have had to be used to experiment with different lens configurations.

What would also be good is if there was a quick way of swapping different lenses in and out of the projector window. Possibly with a part of the holder being permanently secured to the lens to make them easier to use and identify in the dark. And lessen the chances of lens damage.

Standardised projector mounting holes would be another welcome feature, not just to put these lenses on, but other external optics etc. – If someone were to come up with an elegant solution, it could become the de-facto standard, and much quicker than waiting for a standards committee to get its arse into gear.

So does anyone know of any good lens mount offerings?

BTW, as for the lenses themselves, yes I’ve heard the criticism about cost being too high, but really, for what they can allow you to achieve, a set of these are an excellent, (in fact), essential addition that any laserist performing audience scanning should have in their armoury.

Beam quality of the original sources can be a slight issue in that any mismatch between different laser types can get accentuated when the beams expand, but as long as the lasers are not really cheap and nasty, the resulting effect can look very good. It is great to watch laser effects knowing that they have had the sting taken out of them, but are still looking good. And the not get the annoying afterimage when your eye is hit.

James

[norty303]

I was going to design one with someone here, but got too busy. I may still pick it up and see. I was thinking about some half moon rubber edges to assist with handling and snug grip in the mount. They feel very vulnerable.
I used the lenses at a festival at the weekend and they do a fantastic job. I was using the -6 diopter ones (the highest power) on a pair of 800mW 532 projectors. Power set to 60% in a BAM and they metered right on the nose of MPE at the crowd.
In use, it was very difficult to see where the lenses started and ended, and the refraction went completely unnoticed (if you project a circle with a lens, it gets broken at the lens, I thought this would be really noticeable, but it wasn't)

I deliberately avoided crowd scanning with the RGB's due to the way the lenses affect different beam properties, but it wasn't needed anyway.

[White-Light]

Hi james,

Pangolin are developing their own mount which I understand has more adjustment in more planes than the Kvant and is universal.

When it will be available I don't know, I understood later this year although over to Pangolin on that one.

[norty303]

Last comma I had with Bill a about it was that it was still in Solidworks awaiting a suitable resource window, which is what prompted me to look into my own

[andy_con]

what adjustment is needed?

surely any good projector will have the beams coming out parallel so you only need to move the lens around the projector aperture to get the central?

[norty303]

You need to be able to tilt the lens so that the beams from the scanner are exactly parallel with the top flat edge. Otherwise you get ghosting and refraction. I saw this clearly at the weekend, although it's not a deal breaker.

[andy_con]

by ghosting im assuming you mean reflections?

[sbk]

Ghost images are quite visible once you know they exists, but I believe I was the only one to notice them...
You can see this in this picture of my last show. Well, I have to find a way to add some extra adjustments to my mounts!

[White-Light]

You need to be able to tilt the lens so that the beams from the scanner are exactly parallel with the top flat edge. Otherwise you get ghosting and refraction. I saw this clearly at the weekend, although it's not a deal breaker.

I don't know about parallel, although if you've tried it no doubt right Norty, but I do know the angle of incidence with the lens is critical.

[Jem]

Parallel is correct. Tip the lens too much either way and you'll envoke either reflection or refraction at the top edge of the lens. When set up correctly (easy) you get neither of these effects. In this case the beam crossing the threshold is barely disturbed and the desired effect is achieved, ie, a smooth crossover

It is also important to note that the horizontal centration is equally as important, the geometric Center of the lens should be in the exact centre of the beam path to avoid prismatic effect. All these things are quite easy to achieve with a little adjustment and patience. An adjustable mount is being worked on

As has already been stated, the effect of using the correct lens power, centred correctly, is quite amazing and allows for much safer audience scanning. In the vast majority of cases the audience won't even know, or notice, what you've done. But the end effect is a much more pleasant (and safer) experience for those being scanned.