Here’s the results of an experiment using the “redscale” technique. This involves exposing colour film backwards, i.e. emulsion side away from the lens.
It's actually very easy to expose the film backwards. Using a spare film canister, film can be wound from its canister into the spare the wrong way round. The film is then put in the camera, exposed then processed normally. Instructions here
I actually did this by total accident a while back but didn't catch on to how it could be used as an effect.
There's a number of photographers shooting this way and producing some interesting results, seeing this as an alternative to cross processing.
So I thought it was time to try it out properly. I used some very cheap unbranded 400ASA print film in a cheap plastic panoramic camera, with the panoramic insert removed (makes a rather nice toy 28mm wide angle camera). One bright sunny Sunday afternoon I went out and clicked away....
The results came out very red, and very under exposed, much more so than my previous shot produced with 100ASA film. Not what I expected!
There were also some crazy "light leaks"
So what makes it work and what's going on? My guess is it’s the anti halation layer at the back of the film acting as a very dense filter. Some films are denser than others, with different filter characteristics. To test this out, I held some unexposed bits of both films up to a bright lamp. The lamp was clearly visible through the 100ASA film while the 400ASA film almost totally blocked it out.
So it's worth looking through the leaders of a couple of different films before selecting one to try this technique with!
As for the light leaks, any light managing to creep around to the reverse side of the film, reflecting off internal surfaces would hit the emulsion.
I know you posted this months ago, but I just found it and am definitely going to try it out. There's so many interesting ideas these days regarding making pictures, it's hard to keep up!