FreeTrack Forum

For light blocking filter now we use exposed film or floppy.

I was watch on Galileo how they test home made night vision. It is made from digital foto and IR light source was made from ordinary flash light.

Point is they made IR light source from flash light and create filter from red and blue transparent plastic wraps for gift or flower. it was made with 6 red and 5 blue transparent plastic and was efficiently passing true only IR spectre and block other from flash light. when it was turn on it was complete dark but on camera screen you will see everything like on night vision.

Could we use it opposite way to pass only IR light to web cam and block the rest more end efficient than it is now made by exposed film or floppy?

This filter is made in 11 layers starting with red, blue, red, blue, ... red.

I still didn't have time to test it but idea is here maybe could be break true and reduce need to remove IR filter from webcam.  

Well, the idea to put ir-filter on webcam is to block parts of infra-red light-spectrum up from 700nm to avoid interference on the image sensor.
That's why technically we better have to say ir-cutoff-filter.
So when working with ir-LEDs on the contrary we need this ir-band and not the part of visible light. That's why we use film or floppy disk for a ir-pass-filter, that blocked visible light and let parts of ir-light through.
By the way as you can see in this thread, floppy disk is a really poor filter that  I can't recommend.
There's no way to avoid putting of ir-cutt-of-filter from webcams to make freetrack really works.

Multiple layers of colored films is a very effective way to create a ir-pass-filter (or visible light-cut-off-filter). Layers of red and blue spotlight-filter works great. Film from 3d glasses also.