I've been enjoying experimenting with the trichromy process lately.
It's an old process, dating from 1868, reproducing color using three black and white exposures filtered into red, green, and blue channels.
A "perfect" trichromatic image would involve three completely simultaneous filtered images, each taken at the exact same position in relationship to the subject. This would result in a combined picture with the red, green, and blue channels matching up perfectly, and the subject not shifting in position at all.
We live in an imperfect world, and despite my best efforts, it's darn hard to make a perfect trichromatic image. And, given that color film is readily available, what's the point of making a technically perfect trichromatic image anyway?
What I've been really excited about, though, is intentionally playing with imperfections in the process. By intentionally adding movement & changing the relationship between the camera and subject, the red, green, and blue channels don't line up perfectly. This results in "rainbow" effects in the final, combined image.
The image below shows the three individual black and white photos taken with different colored filters in front of the lens, and how they're combined into a final "color" image. Check out the difference in skin tones the different colored filters produce. And where the layers don't line up, rainbows result. The model's hair blowing in the wind created this cool effect here.
These shots are examples of intentionally messing with the process. All were taken with a $15 Minolta SRT-101 35mm camera, inexpensive lenses, black and white film, and $1.00 Chinese plastic red, green, and blue filters.
Several of the photographs in my Anima gallery feature this technique.