I’m doing a couple of projects involving motion tracking that require me to detect IR LEDs. Right now, I have a choice between two cameras, an $80, 500xsomething B&W security camera with no IR filter on the lens and a $3000 1024x768 machine vision camera which has a c-mount lens with an IR filter over the top.
Obviously, if practical, I would far prefer to use the camera with the higher resolution but the LEDs just aren’t showing up bright enough for that to be practical out-of-the-box. A quick search on the internet reveals that there are either $400+ lenses which claim to be IR sensitive and $20 - $100 lenses which also claim to be IR sensitive and come with a ring of IR LEDs around the edge which turn on automatically in low light. I don’t claim to know why the second group is cheaper but my googling has not revealed a non-LED studded IR lens for less than $100.
Alternatively, I know that people have removed IR filters from webcams but I was wondering if anybody had done it for c-mount lenses or knew how the IR filtering on a standard c-mount lens is achieved.