Absolute Beginner's Guide to Digital Photography

into the layer. Thus a color dye image appears in proportion to the amount

of developed silver in each layer. The silver is then bleached out, leaving only

a negative dye image. Cyan dye forms wherever the film was exposed to red

light, magenta dye forms wherever the film was exposed to green light, and

yellow dye forms wherever there was blue light (see Figure 20.4).

296 ABSOLUTE BEGINNER’S GUIDE TODIGITAL PHOTOGRAPHY

FIGURE 20.4

Color negative

layers.

Red

Green

Blue

White

RGB RGB RGB

3. After development, bleach and fixer baths dissolve the silver in the layers.
   Only colored dyes remain in the film, forming the “negative” image, which is
   actually the image in cyan, magenta, and yellow.

The process of developing slide film, also called color reversalfilm, is more complex.

This type of film is developed to make a silver negative first, but no color dyes are pro-

duced. A second developer chemically exposes and develops the remaining unexposed

silver halide, thus producing a silver positive. The second developer also creates dyes

that form a positive color image, dark in the shadows and transparent in the high-

lights. Next, the silver is bleached out, leaving only the dyes of the positive image.

Printing Process

Color negative printing paper employs the same principles as color negative film.

1. During printing, light from the enlarger passes through the color negative.
   Wherever dyes are present, only light that is the same color as the dye can
   pass through the film to expose the paper (see Figure 20.5). A latent image
   forms in the paper.


2. During development, a negative dye image forms in each layer along with a
   silver negative. This is identical to the way color film develops.


3. After bleaching and fixing, only dye remains in each layer. As the film image
   was a negative, the negative dyes in the photographic paper create a positive
   image.