Color Photography

above: Fall scene at Swan Creek Metro Park and Preserve, Toledo, Ohio. Kodak color print film (type unknown); Pentax ME Super 35mm camera with 50mm lens. The negative was scanned in, using an HP S20. Note that this image's fidelity is not as good as the the images above: one of the many reasons for choosing slide (transparency) film over print film.

Color Perception

There are two basic ways by which we perceive colors (or, more accurately, hues) of objects around us:

Direct emission of light waves in the frequency of the observed color. Example: you see the red in the rose on your computer monitor. The cathode ray tube is emitting red-tinted light.

Absorption all other frequencies, reflecting back to your eye only the light wave, or combination of light waves, that appears as the observed color. Example: to see a yellow object -- such as a banana -- it is absorbing the blue part of the spectrum and reflecting the red and green parts back to your eye, which translates the combined frequencies as "yellow".

Color Photographs

Subtracting Colors (hues)

Images made by mixing printing inks and paints form colors by "subtractive" mixing. This gives different colors to additive since the pictures themselves are not light-emitting sources. The pictures reflect some of the primary colors (red, green and blue) in the white light that illuminates them, and absorb or subtract the other primary colors. Humans see the reflected primary colors added together.

No matter how multi-colored prints or slides may appear, they are comprised of only three secondary colors arranged in layers. When we look at photos, light passes through the layers and combines to give full color. Developing a print film produces a color negative; in a slide (or transparency), a process called color reversal forms a positive image on the film.

Color Reversal Process:

Unexposed slide film: The film contains three color-sensitive layers. The one in the middle is sensitive to green.

First developer: Magenta light contains no green. It does not expose the layer, so silver develops.

Color developer: This attaches a magenta dye to the silver particles.

Silver dissolved: Dissolving the silver leaves the layer colored magenta.

Color Photography

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Color Science Primer	Color Photography (continued) >>
above: Close up of rhododendron at Toledo Botanical Gardens. Fuji Velvia film; Olympus OM 2N 35mm camera with 50mm lens
above: Red roses at Toledo Botanical Gardens. Fuji Velvia film; Olympus OM 2N 35mm camera with 50mm lens
above: Red Lily at Toledo Botanical Gardens. Fuji Velvia film; Pentax ME Super 35mm camera with 50mm lens
above: Pink hibiscus at Toledo Botanical Gardens. Fuji Velvia film; Pentax ME Super 35mm camera with 28mm lens
above: Fall scene at Swan Creek Metro Park and Preserve, Toledo, Ohio. Kodak color print film (type unknown); Pentax ME Super 35mm camera with 50mm lens. The negative was scanned in, using an HP S20. Note that this image's fidelity is not as good as the the images above: one of the many reasons for choosing slide (transparency) film over print film.
Color Photography (continued) >> All image on this sizes reduced several orders of magnitude via Adobe Photoshop elements.
Color Perception There are two basic ways by which we perceive colors (or, more accurately, hues) of objects around us: Direct emission of light waves in the frequency of the observed color. Example: you see the red in the rose on your computer monitor. The cathode ray tube is emitting red-tinted light. Absorption all other frequencies, reflecting back to your eye only the light wave, or combination of light waves, that appears as the observed color. Example: to see a yellow object -- such as a banana -- it is absorbing the blue part of the spectrum and reflecting the red and green parts back to your eye, which translates the combined frequencies as "yellow". Color Photographs Subtracting Colors (hues) Images made by mixing printing inks and paints form colors by "subtractive" mixing. This gives different colors to additive since the pictures themselves are not light-emitting sources. The pictures reflect some of the primary colors (red, green and blue) in the white light that illuminates them, and absorb or subtract the other primary colors. Humans see the reflected primary colors added together. No matter how multi-colored prints or slides may appear, they are comprised of only three secondary colors arranged in layers. When we look at photos, light passes through the layers and combines to give full color. Developing a print film produces a color negative; in a slide (or transparency), a process called color reversal forms a positive image on the film. Color Reversal Process: Unexposed slide film: The film contains three color-sensitive layers. The one in the middle is sensitive to green. First developer: Magenta light contains no green. It does not expose the layer, so silver develops. Color developer: This attaches a magenta dye to the silver particles. Silver dissolved: Dissolving the silver leaves the layer colored magenta.		Primary Colors for the additive process Secondary Colors (Magenta, Cyan, Yellow) are used in the printing process Tertiary Colors (the "Color Wheel" designed by Isaac Newton): formed by mixing one primary and one secondary color
Learn more... Exploring Color Photography by Robert Hirsch (Amazon.com) A college-level textbook for students and serious hobbyists. This book describes tools and techniques necessary for the expressing artistic and scientific ideas through photography. The approach is sensible, explaining how theory relates to practice. Assumes that readers have a working knowledge of b&w photography. Includes a wide range of color photos.