Stu,
Interesting idea that should accomplish what you have in mind. Contrary to
what David Adin writes, the CCD sensor is sensitive to infra-red (heat)
directly emitted from objects, not just light from a source on the camera.
Normally, an infra-red blocking filter is placed in front of camera CCD
chips to reject this component which just tends to blur the visible image.
However, with the filter removed, the CCD is pretty sensitive to heat,
including body heat which makes it possible to see through light clothing.
For that reason, this "feature" stirred up some controversy a few years
back, but I haven't heard anything recently. I seem to recall that Sony
discontinued this feature in response to the controversy, but I'm not sure
BTW, a CCD chip is most sensitive near the red end of the visible spectrum
and extends a ways into the near infra-red. That's just good enough to pick
up some of the light emitted by even body temperature and should certainly
be able to see radiation from objects at the temperatures of an engine
compartment. Try looking at the radiator when the engine is running, for
example, to see the temperature distribution at least qualitatively.
Bob
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