Re: Cheap camera - A User Report

Steve Loboyko (slob@mindspring.com)
Tue, 14 Feb 1995 01:45:46 -0500


Following up on my response to the question about IR response of this camera....

I should have expounded a bit on the IR filitering. The $150.00 camera
module also sold by BG _does_ apparently have a coated lens with an IR
filter. This is why I had to use more IR LED's on that camera to get around
my backlighting problem. Of course, with that camera module, you have to put
it in a case and make your own power supply or tap off of your PC, which I did.

The lack of this filter undoubtedly explains why the $150 camera is not
quite as sensitive as the $90.00 one; semiconductors seem to work best with
lower frequencies ("blue" LEDS are hard to make and not very efficient, for
example). I know a little about CCD's because I built a CCD camera for a
telescope. Of course, with a telescope, you want _all_ the light, so there
is of course no IR filter.

As far as the filter itself goes, if you are afraid to take apart your
camera, you could simply place it in front of the lens; I suggest mounting
it in the "barrel" simply because it would look better that way...

________________________________________

Steve Loboyko
Software Engineer
cR Solutions, Incorporated
11285 Elkins Rd Suite G-1
Roswell GA 30076

slob@mindspring.com
http://www.mindspring.com/~slob/home.html

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