Inexpensive infrared edge/cutoff filters

[Stephen Intille <intille@xxxxxxxxxxxxx>]

Hello, 

I'm doing research in computer vision using IR instead of visible light
(because it allows flexibility in visible light in a scene). I'm trying
to get a setup created that uses two distinct bands of near-IR light
(probably one centered around 840nm and one centered around 950nm). 

What I need are inexpensive filters to allow me to create light
using IR emitters that clearly falls either in the 840nm range
or the 950nm range. I've found edge filters and some cutoff filters
that are approx $50-100 for a small (1 inch diameter) filter. 

The problem is I need many of these and I need bigger filters. The
emitters typically have a 5x5 opening that needs to be covered
with a filter ... and I need a bunch of emitters. 

Can anyone think of an inexpensive way to flood a small room with
2 bands of IR?

What I would then do is put a filter over two cameras so each camera
sees a different band. 

Thanks for any ideas,

Stephen Intille
intille@xxxxxxxxxxxxx



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