I/R with the qcam
Nat Friedman writes:
> A friend and I have independently discovered that the Quickcam seems to pick
> up infrared light (from a TV remote control...). Can anyone verify this?
> It would be interesting to use a large infrared light as an I/R flash
> to take quickcam pictuers in the ``dark.'' There are obvious complications,
> but it's a neat thought.
Hmmm... Might work pretty well. LEDs don't care how much peak
amperage you put through them, so long as the average stays below the
rating. So if you put a 1 amp pulse through a 20ma IR diode for
50msec, that should produce a nice flash. And you can use a capacitor
to provide most of that current, because on average you only need
20ma. And we're already using the parallel port, which does have a
couple of control signals that the QC isn't using. You could tie a
one-shot to one of those lines, and trigger it just after an exposure.
But that would only work for single exposures. For multiple exposures
you'd need a bank of 20 LEDs at that current/period combination.
-russ <email@example.com> http://www.crynwr.com/~nelson
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