It is clear that CCD arrays are sensitive to IR. If you have not yet
done this, watch a TV monitor while the CCD camera is aimed at someone
operating a remote-control for a TV, VCR, etc. The remote-control uses
an IR-LED and it comes across as bright white on the typical CCD
camera/monitor. I suspect this means the near-IR is making it through
the camera lens and also through all three of the RGB filters on the
CCD array. This is not surprising... near-IR goes right through many
colored dyes, inks, filters.
If we attach a filter over the lens to block the visible and pass the
IR, I do not doubt that we can get some interesting images. The CCD
arrays have wide dynamic range. If the visible light is removed, I
assume the "gain" will automatically crank up, and anything reflecting
or emitting near-IR might be imaged quite well. In fact, all three
color bins (RGB) will pick it up, so you essentially have "automatic
binning" of IR light on a color CCD.
Therefore, I do not automatically discount these claims as a scam.
Even though I have not tried this particular experiment, I have taken
photographs with IR film. They're pretty interesting.
Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817