Here is a picture of the huge DI setup we are building. Only half of it will be multitouch (screen size approx 900x675mm), the other half will be video projector/lightbox. We are building it for our university’s fashion dept to show portfolios etc at fashion shows.
We are getting some bad vibes about using rosco for DI setups - it not being well suited to letting IR through. Anybody got any advice?
@Fairlane or whitenoise - what do you guys use? Do you have your diffuser on top or bottom of your acrylic?
If we have enough IR illuminators will it work with rosco? (we already bought some :-?
First of all , wellcome to the forum , second , that thing is huge.Sorry but i haven’t built a DI box so far , working on one tough.You should go trough some of the older project logs on here (the showcase category) , that should answear your questions and give you pointers.
Hey Gordee, nice box! I’m using 4mm Frosted Glass as a diffuser/projection surface (no acrylic). The ‘frost’ side of the glass piece is facing downwards (towards the projector), and the user touches the other side of the glass. That way I’ve done away with acrylic, rosco, tracing paper etc…
Thanks for your reply. The thing is we have bought acrylic and rosco already.... What can we do to minimize further expenditure?
Use a different diffuser or get loads of IR?
Try using a piece of tracing paper or architects paper. It’s cheap and a great way to test the table. You want the IR to be diffused enough on the screen and still be able to pass through. I’ve had great results with baking paper too.
It’s basically a self adhesive film that can be used for decoration on windows/mirrors etc or to add privacy. It provides a projection surface and diffuses the IR well. We bought 2m for £22 plus p+p. Great for us as we can cover the whole of the acrylic in one piece and didn’t have to pay a fortune to get the acrylic sand blasted!
Waiting for new illuminators which should arrive today, but will post some more pictures up for anyone that would like to see the surface very soon.
Nice. We’re building one that big too, but the entire surface is MT. We’re using Rosco, we really need that lovely grey surface (I’m fussy) but are hoping to get around IR issues by have 200 IR LED’s inside the box. If it doesn’t work, we’ll add another 200 at a time until it does.
Which uni do you work for, I’m in Norwich. We should collaborate and build a multi-touch room.
Yeah we’d really love to use the Rosco, the image is so nice on it but it really does block IR so be careful. Our illuminator is 148 LED and even at close range it does not penetrate! Maybe more light would do it, but it would have to be a hell of a lot more. When we first discovered this problem, we were really panicking as our deadline was approaching fast! Can’t believe we didn’t consider this beforehand, but just goes to show how valuable research is…
We are in Newport University (South Wales) and would be happy to collaborate. A multi touch room eh?! And we called our project ‘ambitious’!
I just found out that our illuminators are delayed :-( rang the shop and apparently UPS ‘have made an error’ which when pressed, turns out to mean ‘the illuminators are still at the shop’. Paid extra for next day delivery and they forget to put it on the van!
We are in Newport South Wales so the opposite side of Britain! Just found out our illuminators are now arriving tomorrow :-( We would love to use rosco too, maybe we still will if these illuminators do the trick. Are you making your own illuminators? If so what LED’s are you using? Are you using more than one camera?
It’s a convention! We make our own illuminators from Osram 485P’s. I think the IR can penetrate, you need to make sure you get the camera to match the wavelength of the LED’s. We ordered Rosco Greay and Black, we really want to build a black table with white visuals, we are thinking o ways to let the IR go through. Hell, if the light from the beamer can, surely the IR from a thousand LED’s will.
Using one camera with mirrors. Hopefully having the cabinet pressed from steel and polished for us, our total budget was £1500. If it works though I think the school will want a few more dotted around ,so there is plenty of opportunity for collaborative work.
Nice budget! Ours is £600 and frankly, isn’t enough! We were lucky to get any money at all really, the client didn’t actually want a multi touch box (probably didn’t even know what one was) all they wanted was some visuals to be projected behind the catwalk for a fashion show (boring!). We managed to convince them that what they really wanted was a multi touch display that would show the designer’s portfolios etc at the show, and also that they should give us money for it
Would love to see what results you get with the rosco. At the moment ours is rolled up unused in a corner somewhere feeling neglected. Will probably sell it or keep it for a future project.
We’re building one that big too, but the entire surface is MT. We’re using Rosco, we really need that lovely grey surface (I’m fussy) but are hoping to get around IR issues by have 200 IR LED’s inside the box. If it doesn’t work, we’ll add another 200 at a time until it does. 
