Originally Posted by juliohaynie
What is the purpose of that?
Lets see... Because I can
Actually the real purpose is "to see the invisible light".
I remember there was a whole IR controversy about a Sony camcorder a few years ago -- something about seeing through otherwise opaque fabrics at the beach... ('nuff said)
If you don't believe me, google it.
Originally Posted by Jasper101
Do you have to have a IR source for this to work? or do you just have to put a negative film strip in front of it?
Yes you need an IR source.
When photographing outdoors, the IR source is the sun of course.
The exposed negative is just used to filter out "visible" light. This camera should also work in pitch black with an IR source -- without any filtering.
(anybody have one? take some pics and post up!)
As for filter materials, I'm sure there are dozens of different types that can be used. Exposed negatives are not very high quality as filters - they leak a bit of red. But the real plus is they're cheap
and readily available