Building a Multitouch GUI

Yesterday I recieved specimen of various rear projection and other plexiglas from röhm switzerland. http://www.plexiglas.ch/

I was surprised how little they knew to tell about their rear projection plexiglas sortiment, called PLEXIGLAS XT RP. It seems all very expensive, very special, low on stock, and additionaly some sorts would have to be orderer in other countries.

I was lucky that they had some specimens (the only ones left) to send me.

So i feel lucky in that respect and I want to show you those specimens.

I will hold them in front of the beamer, like this:

First we have here a 7D009 RP. They tell me this stuff actualy exists for decades now, the price per square meter is awesome in the negative way, but also on a basis for negotiation. You might pay between 600 or 1200 CHF for 1 (!) square meter of this material, and you have to buy at least a whole standart size plate which is like 2×1 meters.
Here is how it looks:

You might not get the whole impression through this photo, but let me assure you, it looks like a very clear and bright computer screen (the room appears much darker than it really is,but it has the same light as picture nr. 1, it is the camera that adjusts to the high brightness of the beamer picture this way, sorry about that)
Compared with this the cheap rear projection foils I used so far look and feel like the cheapest crap. What I like about this 7D009 RP is also its thickness of 5 mm and its backside is already antireflex with a nice grey diffusor implemented. It is very robust, and stiff.
Also there is no hotspot of brightness, it is so evenly distributed throughout the whole plate.
Additionaly both front and rear projection is possible with this plate.
Here another picture of 7D009 RP:

The other specimen I got is the 99562 RP (not 99561, I am still waiting for them to send me a 99561).
It will cost around 350 CHF per sqm, which is also the price for the 99561. Sadly it only comes in a standard thickness of 3 mm, so for a big plate this might be just too little for enough stiffness and stability.
You dont want someone to use too much force on this, but still it has a high stiffness and is quite immune to scratching. Also you cannot just order 1 square meter of this model, you need to order a different standard plate of 3×2 m.
Here are 2 pictures:

You can cleary see the difference, a highly visible hot spot region of brightness…
I do not know yet if this concerns only the 99562 RP and NOT the 99561 RP. But apart from that drawback these RP plates are also very bright clear and with much contrast.
Both sides are equally good for rear projection, but front projection looks worse.

Thank you very much to the people of Röhm. They where so nice to also send me thin surface acryl foils (because since you pay sooo much for the RP, you probably dont want to let everybody scratch and touch it with their bare fingers, altough they have a high immunity to scratching). Also they send me their standart sortiment of PLEXIGLAS SATINICE:

Addendum: Let me show how the 2 RP Screens’ transparency is, because of course we want to track fingers and fiducial markers with them:

Original picture:

front and back side of 99562: The transparency is clear and sharp.

front and back side of 7D009: The one Side reflects and is not sharp, the other has a diffusor on it and is sharp.

This entry was posted on Tuesday, June 3rd, 2008 at 5:05 pm and is filed under DI.