Quote Originally Posted by Nikanon View Post
Color infrared is impossible with black and white film, there are no dye couplers in the emulsion to record individual colors, simply the silver halides (plus sensitizers) reacting with photons. Recording black and white film with different color filters will only give you different tonal relationships, but not record any color information.
As mentioned: not only will it work, it'll work well. A lot of colour work was done with b&w film. The idea of colour sep goes waaay back. In my own research on the topic, I quickly ran into James Clerk Maxwell; yes, the Maxwell of del dot B equals zero fame. That was around the 1860!!! Apparently Maxwell was the first to propose colour sep for capturing and displaying colour images. Nobody was thinking of multilayer colour film at the time, much less colour roll film or c41 or e6 or whatever.

Doing IR colour sep will be easy. The interesting wrinkle is what colour channel you dump the IR info into; IR is, of course, invisible to us and doesn't have a colour. So it is a matter of choice. For spy photos you'd probably want the IR to be something other than red so that it stands out from that adjacent colour. But for more pleasing images I suspect that putting the IR image into the red or deep red channel of the final image will work. People can simply try and see for themselves... many creative possibilities here.

Of course, the individual b&w images could also be developed as positives, they don't have to be developed as negs.

Smart chemists like Ron could tell us how to make IR autochromes.

As certain film options go off the market, we'll simply rediscover all the ingenious things that people used to do. It'll be fun, it really will.