Hi All

I have bought 3 pens from ebay (wiimoteproject) was the user  - and used one to convert into a spray can - but using with a rear projection screen it doesn't seem to work very well. It's actually not quite as bright as the other pens - even though it has the same led - the famous Vishay  or at least that's what the listings have said!

Custom made IR pen comes with:
 
High quality VISHAY TSAL6400 infrared LED
 
3 watch batteries (AG10 - 1.5v)
 
IR led specification –
 
Size : 5mm
Wavelength : 940nm
Viewing angle : 50°
Forward voltage : 1.35V
Forward current : 100 mA
Radiant intensity : 40 mW/Sr

Also - having read some information about making pens - shouldn't this setup have a resisitor in it?

I'm wondering whether there is some way that I can use a brighter LED to be seen better through the rear projection screen. Maybe like the ones used in security lights? Any BRIGHT ideas? Like maybe using a reflector or something too..?

I'm using a Da-Lite Fastfold Deluxe 8ft x 6ft Screen with Rear projection surface with spec as follows:

Da-Tex®

Flexible Fabric Screen: A translucent, neutral gray vinyl fabric that allows rear projection in applications where a rigid acrylic or glass screen are not possible. This specially designed gray vinyl surface offers the same high transmission and low reflectance values as a rigid rear projection screen for optimal viewing. It yields excellent color rendition, image contrast and a moderately wide viewing angle. Ideally suited for both lace and grommet and snap button type screens used in portable installations. This material requires tensioning due to its flexible nature. Screen surface can be cleaned with mild soap and water. Flame retardant and mildew resistant. Viewing Angle: 30° Gain: 1.3

Wiimote/s placed 16ft from the screen - as per the 2 x height instruction.

Other problems as outlined on facebook smoothboard discussion with disconnects...not yet resolved

The spray can - is usually touching the screen - and it still isn't working. Obviously I'd rather it wasn't touching

I'm wondering whether the fabric of this screen has some IR filtering built in. I've sent the manufacturers a message to find out! I'll try a few other surfaces too. My ideal setup will be a rigid screen probably made of plexiglas/perspex with a frosted finish. I've seen some posts on the nuigroup forums about rear projection materials so once I find something that works well - I'll share it with the community here