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PHOTOGRAPHY |
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Color film and photos are coated with color dye layers that act as filters to stop various amounts of color light from passing through. This is known as the subtractive mixing of colors, since the filters subtract color from the light passing through. |
| You can use a flashlight and
filters to see how this works.
Here is how red can be made with filters of yellow and magenta. |
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White Light |
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The yellow filter subtracts the blue light from the flashlight beam. The magenta filter subtracts the green, leaving only red light to reach the wall. How do the color layers in a photo mix to form a full range of colors? The 3 color layers are 3 photos of the same scene. The amount of color in each layer matches the amount of each color of the 3 primary colors in the original scene. The cyan, magenta and yellow layers subtract color from the light that you use to view the photo. Since the layers are transparent, all 3 layers can be seen at the same time. Look at the picture below. Notice that the white portion represented by the frost on top of the apple has no color in any of the layers. What you see as white is really the paper backing of the photograph showing through, since no light is being subtracted in that part of the picture.
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photograph |
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| You can see that the green in the image of the leaf is formed by the combined layers of cyan and yellow. The red of the apple comes from the layers for magenta and yellow. If all three layers had the full amount of color in each, then that area would look black. All light would be subtracted in that case. | |
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All other colors are made by variations in the amounts of color in each of the three layers. For example, each layer can range from a very deep color to a very pale shade. Some photos may have many different colors and shades of color. Some colors may be bold and others hardly noticeable, but there are still three layers. |
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