Books

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Events/Exhibits

Film/Video

by John Gage.
University of California Press: Berkeley & Los Angeles, 2000.
320 pp., illus. color + b/w, $35.00.
ISBN 0-520-22611-9, paperback.
Reviewed by Wilfred Niels Arnold, Professor of Biochemistry, University of Kansas Medical Center, Kansas City, KS 66160-7421 U.S.A.
E-mail: warnold@kumc.edu


Humans have a color response to wave lengths of light between 400 and 700 nanometers (nm). Color vision is an integrated process that starts with the generation of signals in retinal receptors, involves comparisons and evaluations of the information that is transmitted to the brain, and terminates with the declaration of particular hues in order to describe a scene. Physical, chemical, physiological, and psychological aspects are all involved.

When a beam of light from an incandescent lamp passes through a prism it emerges as a spectrum, the so-called colors of the rainbow. The following tabulation displays the relationship between "psychologic" color and the wave length of incident light:- red (660 nm), orange (600 nm), yellow (575 nm), yellow-green (560 nm), green (510 nm), cyan (495 nm), blue (470 nm), and violet (450 nm). The specific band (region) of the spectrum which we perceive as green is made up of light with a small range of wave lengths centered around 510 nm. The chemistry and physics of light and vision are mammoth subjects and Leonardo readers may wish to refresh their working knowledge by visiting http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html an instructive internet site by C.R. Nave. Unfortunately, at the interface between the science and the art of color, we are on less chartered ground. The question of whether the practicing artists of today understand anything about the physics of light is an interesting one. Are they pragmatists or do they think about wave lengths and the differential stimulation of our retinal pigments? "Color and meaning: art, science, and symbolism" is the most recent attempt to approach this set of difficult subjects.

Indeed, John Gage strives to deal with all things from the ancient and modern languages of color, through a little science, to explorations of the works of selected artists. Chapters with headings such as "Color and Culture," "Color in Art and Literature," and "Color in History" are appealing and in some cases deliver admirably. In others we get little more than snippets and we are left wanting more. There can be no doubt that Gage has read a good share of the literature about color but too often he assumes that the general reader has already been down the same path and is more interested in his gloss than a full explanation.

Nonetheless there are many items of interest. For instance, illustration number 13 provides an exercise on the phenomenon of color complement wherein the after-image of red is green, as expected, but as Gage remarks in this case it really is a blue-green. According to the author "since about 1800, red's complement has usually been described simply as 'green' - partly because in the system of the three primaries of red, blue and yellow, the complement of each color was deemed to be an equal mixture of the other two."

Color-circles or color-wheels, extended and modified over the last three centuries, are of considerable application but still cause confusion between physics and art. Isaac Newton (1642-1727) was initially occupied with splitting white light into its component colors, with the aid of a prism, and in describing the resultant linear spectrum. He went on to show that light of a 'pure' color could not be further diffracted but, most important, white light could be reconstructed from a mixture. Newton's color-circle (Gage: fig. 58, p. 136) taken from his Opticks of 1704, shows the spectral colors as clockwise sectors in the order of red, orange, yellow, green, blue, indigo, violet. The original significance of these discs was that they look white when spun on a top. This was the kind of evidence that led Thomas Young (1773-1829) to his theory that there are three color receptors (red, green, and blue) in the retina. James Clerk Maxwell (1831-1879) further developed these ideas and he was one of the first to employ a team of observers, including his wife who suffered from one form of color-blindness.

Somewhere along the way, the color wheel became more of an artistic prop than a physical tool. Thus a modern version has red, yellow, green, cyan, blue, and magenta. Magenta (a purplish-red), so-called because it was discovered by the dye industry about the time of the Battle of Magenta (Italy, 1859), is not a spectral color. It is placed in the artistic color wheel, between blue and red, for symmetry and is deemed to be the complement of green, as yellow is to blue, and red is to cyan (compare with bluish-green mentioned above). More attention to these historical aspects might have helped John Gage in his attempt to bridge the divide between science and the arts.

J.M.W. Turner (1775-1851) and Georges Seurat (1859-91), both heavy hitters in the world of color, receive new treatments. Gage enjoins us to worry along with him as he asks "what were these artists really up to!" In each case the author ends with unfair suggestions that they were 'pretending' to be more knowledgeable about color theory than is revealed in their products. Gage seems to be greatly bothered by Turner's local (unnatural) color and with Seurat's mixing dots and dashes of color in the same picture. All of this reminds me of the time a local artist, who favors constructivism, described the mathematical progression that was his basis. A viewer pointed out a seemingly abrupt departure about half-way up the sculpture. He smiled and declared that it was an error, but the whole thing looked better for it.

Gage's format requires some orientation for the reader. Each artistic reproduction or line drawings is accompanied by a caption which ends with a number in boldface, enclosed in parentheses. These turn out to be figure numbers but are never described as such, and are referenced only by plain numbers floating in the margins of the text. They are not to be confused with literature references and notes which appear as small superscript numbers in the text and are grouped in the back of the book by chapter. After searching in vain for a number of key items I lost confidence in the index. In the age of the word processor, the construction of a comprehensive, richly cross-referenced and intentionally redundant index is hardly the daunting task it was for the card-shuffling specialist of yesteryear.

I was disappointed that Edwin Land's hypothesis, that the key to color vision is the comparison of information of longer versus shorter wavelengths about a "fulcrum" of yellow,"does not rate a mention in Gage's work. Because of the occasional gap and failure to develop within the 'science' subtitle, this book is unlikely to find a large audience as a primary source. It will find the happiest home among graduate level courses in which further essays and lecture materials complement the present text. One supposes that the book is used as such in the United Kingdom. John Gage, was formerly Head of the Department of History of Art and is currently Reader in the History of Western Art, Cambridge University.

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