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This A Negative Image: These techniques have the same limitation as the daguerreotype and the tintype: each color photograph is unique. The negative-positive principle was utilized in Kodacolor film (1941), which is similar in general principle to Kodachrome film, except that the image is not reversed to a positive. Dye-coupling development directly converts each emulsion to an image complementary to the color it records. Thus a color negative shows not only reversal of the lights and shades, but also of color. A blond will appear with blue hair and green lips. From this a negative image negative any number of prints can be made by repeating the process with identical triple emulsion coated on a white base.
The negative image was appreciated for its own sake. As Moholy-Nagy wrote, "The transposition of tones transposes the relationship, too."8 The unreality of the negative throws emphasis upon shapes and contours not usually seen.
The phenomenon of edge reversal, known to scientists as the Sabattier effect, was used as a plastic control, particularly by Man Ray. When a sensitive emulsion that has been developed, but not fixed, is exposed to naked .
light and developed again, the image shows a reversal i tones wherever there is a sharp edge. A print from sue a negative has its contours rimmed with black lines. Tl process is generally known in artistic circles as solariz, tion, although that term is reserved by scientists for somewhat similar phenomenon of edge reversal caused b gross overexposure, particularly noticeable in daguerrec types and platinum prints.
A unique property of the stereoscopic image is its apparent size. When properly blended together by the eyes, the paired photographs no longer seem three-inch-square prints, but a single image as large as life.
Because of the small negative size, the lenses of stereo cameras could be of relatively short focal length. this a negative image made it possible to take stereographs of moving objects. |
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