Re: [Frameworks] color separation

From: Jason Halprin <>
Date: Sun, 3 Apr 2011 18:34:26 -0700 (PDT)


Take a look at Lyra Hill's post from yesterday. She used color film with a triple-exposure, utilizing a different color filter for each pass, and has a clip posted on her site. With this method you would not need to print the film three times, as the color information from each pass is already there.

To wrap your head around how different colors of light (addative) end up producing an image composed of dyes (subtractive), take a look at a diagram of film emulsion ( What you have on a modern film stock are different layers of emulsion (at least 3, usually many more), each made sensitive to different colors of light by the addition of sensitizing dyes (except the blue layer, of course, as silver-halide is by its nature only sensitive to blue and UV light). Between these layers are filters which prevent selected colors of light from "activating" the wrong layers.

When you shoot on 3 different strips of B&W film with different colored filters, it would be appropriate to think of this process as "separating" the different layers that are usually present in a single strip of color film. Each would contain the information for one of the primary colors...but would still hold a B&W image if projected. When you print this B&W strip, it will only contain a gray scale, but those tonal values correspond to the values from the corresponding color that was present when it was shot. So, if you print it using the appropriate filter, you are only now tinting the tonal values, and the result is that you now have tonal & hue information on you color print.

In essence, you could also use the incorrect filters, and you will still get an image...only the colors will shift from those of the objects you originally shot.

Check out this link:

-Jason Halprin

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Received on Sun Apr 03 2011 - 18:34:34 CDT