Monday, December 8, 2014

Tri-Color Photographs

Late last year I did some experiments and made a really cool image using the "tri-color" process by which you shoot 3 black and white images with color separation filters (25, 58, and 47), and then combining them to make a "color" image. This is an old technique that was pioneered most famously perhaps by Sergey Prokudin-Gorsky in Russia in the early 20th century.

Anyway, now with digital technology and scanning, this process is even easier. Well, relatively. It's hard to get all the exposures right depending on the filter factor, spectral response of the film, reciprocity, etc. I am still working on it. It's easier on roll film since you can shoot several "groups" of shots, and even bracket, on one roll of film, but I'm trying to do it on 4x5 film.

What I've been trying to do is combine this technique with long exposures to capture motion in a novel way. Amazingly, my first try created a pretty stunning image:

This was back over a year ago but for some reason I never put it up here on the blog.

Since then though I've been trying to do something similar, without much luck. I was lucky last time. The way this works is to find a good time where leaves or whatever are floating down the river at a moderate speed. The exposures above were in the neighborhood of 15-30 seconds if I remember right.

A few weeks ago I had a good opportunity to try this but didn't bring my color filters. Today I tried again, but there just wasn't enough material in the water to show the color streaks, not to mention some weird fogging on the green sheet:

Also the overcast, low-contrast day might not have been the best.

I've found that generally, the corrections for the filters for T-Max 100 are:

Red 25: 2.5 stops
Green 58: 2 stops
Blue 47: 3 stops

I'll keep trying!

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