>>http://www.cs.cmu.edu/~dellaert/aligned/
>
>Thanks for that URL, Dragan. They're fabulous. I understand the principle of taking 3 photos, each with a different coloured lens, but when I see the resulting 3 B&W images and know that combining them gives colour - that's where my brain goes "DOES NOT COMPUTE!" :-)

I figure the guy would have made transparent positives, dyed them in RGB, and then either overlapped them or projected them in sync one over another, each through one of R, G and B filters, pretty much the way some of the first VGA projectors were working, the kind that had three lamps.

Either way, it was ingenious.