cerupcat - 12 July 2008 08:41 PM

Rosco won’t block ALL IR though and still lets in way too much IR for daylight use. I’m not sure of anything that’ll block ALL IR and still allow for projection.

When I performed the tests outside, I could barely read my laptop screen.  I think the goal should be for the MT to work at a lighting threshold where the display is still luminous.

Taha - 12 July 2008 08:35 PM

… as well as there are various IR blocking films available… but perform on only so so nothing really great
Taha

There a many new solar window tints designed to better insulate by blocking IR.  I found one called Ecotint.  Their Ray-Barier line claims a 95% IRR (Infrared Rejection) and a 63% VLT (Visual Light Transmission.) Another one is LLumar.  Also the specs for 3M Crystalline 70 and V-Kool 70 look good.

These window tinting products are really dark, if you used rosco grey as a projection surface apply thins on top then your image will have a really high contrast… But however if you used Rosco Twin White or Vellum to project on it may turn out ok, but im not certain though.... im basing this on Tinkerman picture http://nuigroup.com/forums/viewreply/12761/ where he has used vellum to project on and put on IR blocking film on top of it.

Taha

Hi rdagger!

Read your posts and found they are very useful. Hope I can contribute something here.

I have a suggestion it may block all IR light on top of the screen.
That is.... Polarizer film. Take a look at my rough drawing.

Polarizer film like this : http://www.3dlens.com/polarizer.htm

I was thinking more in the way of the IR blocker above the laser, and then when you push your finger down on the IR blocker and the silicone, the IR blocking filter will break the laser light and throw the light downwards to the camera.. If you see what I mean?

ole_andreas86 - 13 July 2008 03:45 PM

I was thinking more in the way of the IR blocker above the laser, and then when you push your finger down on the IR blocker and the silicone, the IR blocking filter will break the laser light and throw the light downwards to the camera.. If you see what I mean?

Are you talking about the LLP or FTIR?

~Alex

First I was thinking FTIR, but LLP may be better suited

ole_andreas86 - 13 July 2008 03:56 PM

First I was thinking FTIR, but LLP may be better suited

There is no silicone used in LLP setup. Furthermore any IR blocking layer will block the blobs created above the sufrace so this will not work well.

~Alex

hehe, okey. What if you use a FTIR setup and the IR blocking film will be on top of everything? If it doesn’t work, then nwm

Alex is right. If you block the IR wavelength the IR lasers blobs will not make it to the cam

Great jobs, buddy!!! your experiment is very helpful!! thanks for your work!!

For anyone interested I’ve stumbled on a companies website producing high grade IR filters for under $10 Aussie.
http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1918

Soon as I get the time to order and test these out I’ll post my results, till then see if you can beat me to it

Ruvy.

Ruvy - 12 November 2008 08:51 PM

For anyone interested I’ve stumbled on a companies website producing high grade IR filters for under $10 Aussie.
http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1918

Soon as I get the time to order and test these out I’ll post my results, till then see if you can beat me to it

Ruvy.

Those are longpass filters.  They allow all IR light to pass.  This is only as good as a photo negative.  Bandpass filters only allow a band of IR to pass and are much more effective.