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Lesson Four Seeing Color / Color Constancy

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Lesson Four Seeing Color / Color Constancy © 2015 Cheryl Machat Dorskind! ALL RIGHTS RESERVED! MORE About Color! Lesson Four! Seeing Color/Color Constancy! ! ! Lesson Four! Seeing Color / Color Constancy! ! “Intuition suggests that you open your eyes and viola: there’s the world with all its beautiful reds and golds, dogs, taxicabs, bustling cities and floriferous landscapes. Vision appears effortless and, with minor exceptions, accurate. There is little important difference, it might seem between your eyes and a high-resolution digital camera. What intuition suggests is dead wrong.” David Eagleman Incognito: The Secret Lives of the Brain ! Lesson four explores “seeing color” and color theory topics that have interested scientist and psychologist for a long time. We’ll take a look at Color Constancy, Simultaneous Contrast, After Image, and the Purkinje Effect. We will also examine the colors yellow and blue, which are the polar opposites on the visible light spectrum and the essence of warm and cold dichotomies— motifs used in art for centuries. The assignments that follow provide opportunities to experiment with color theory. ! To help understand the concepts explored in this lesson, I have created a glossary of the topics and listed them in the beginning of the lesson for easy reference. ! © 2015 Cheryl Machat Dorskind ! www.cherylmachatdorskind.com! All Rights Reserved! Page #"1 © 2015 Cheryl Machat Dorskind! ALL RIGHTS RESERVED! MORE About Color! Lesson Four! Seeing Color/Color Constancy! ! Glossary! Color Constancy Seeing only the colors we expect to see. ! Simultaneous Contrast: When two different colors come into direct contact, the contrast intensifies the difference between them. (Art Fundamentals, Ocvirk, Stinson, Wigg, Bone, Cayton, 11th Edition, McGraw Hill, NY © 2009, page 311) ! After Image “An “After Image” is a ghostly but brilliant apparition of a complementary color that appears after gazing steadily at a hue, then shifting the eyes away to an uncolored surface. This visual sensation is one of the most startling aspects of color and one that has intrigued scientists for centuries.” (Color, Bette Edwards, Penguin, NY, © 2004, page 86) ! Purkinje Effect An increasing sensitivity to the shorter wave-lengths (violet, blue, green) as brightness decreases. Likewise, a corresponding decreasing sensibility for light of longer wave- lengths (yellow, orange, red). The effect may be seen on any colored surface at twilight illumination. For example, let’s visualize a blue and a red flower, which appear the same brightness before sunset; they will begin to look different (in this respect) as twilight deepens. The red flower will appear darker more quickly than the blue flower as daylight fades to dusk. Finally all color disappears. (http://www.visualillusion.net/Chap09/Page07.php) ! Motif A design unit or pattern that is repeated often enough in the total composition to make it a significant or dominant feature. Motif is similar to “theme” or “melody” in a musical composition. (Art Fundamentals, Ocvirk, Stinson, Wigg, Bone, Cayton, 11th Edition, McGraw Hill, NY © 2009, page 309) ! © 2015 Cheryl Machat Dorskind ! www.cherylmachatdorskind.com! All Rights Reserved! Page #"2 © 2015 Cheryl Machat Dorskind! ALL RIGHTS RESERVED! MORE About Color! Lesson Four! Seeing Color/Color Constancy! ! ! Color Constancy Imagination is often equated with creativity. But consider this: Artists are often credited as imagining, but is the artist really seeing something imagined? Or, is the artist seeing what really is, what others ignore for one reason or another? Perhaps some are too busy to stop and see. ! How we perceive color is biased by our culture, light, and viewing circumstances. Colors are in a continuous state of flux and are influenced by their neighboring colors and memory. Ask two people what the color red in Coca Cola looks like, and they are likely to describe two different colors. Josef Albers, a Yale professor and author of The Interactions of Color, a treatise on color used as a teaching guide for color theory, discovered that people have a poor memory of color and proved that you could always count on disagreement about color. ! Color theory, specifically color constancy, tells us that “We see what we want to see.” You have probably seen the video of the woman with an umbrella walking through a group of basketball players, or the gorilla walking through? If not, here is the link. This video is a terrific visual illustrating the fact that we see what we want to see. (http://www.youtube.com/watch? v=D_m_9N_3u7o; http://bigthink.com/ideas/20583) ! While the camera is not a mirror image of reality, the camera sees more, especially when it captures the colors of light. For example, a white paper illuminated by the northern light (from my office window) will look white in our mind’s eye; if I move the paper to the other side of the room (into shadow), the camera will record this light shift and the paper will look bluer. But to me or you, to the naked eye, the paper will remain the same color white we saw exposed by the northern light. It’s simply white. This principle is known as “Color Constancy.” As another example, let’s imagine a lemon. It will be a yellow lemon in our mind’s eye regardless of its placement (its light source). ! !Colored Shadows! Color Constancy is especially evident when looking at an object that holds highlights and shadows. For example, when we look at a tomato, we expect it to be red all over, even when the © 2015 Cheryl Machat Dorskind ! www.cherylmachatdorskind.com! All Rights Reserved! Page #"3 © 2015 Cheryl Machat Dorskind! ALL RIGHTS RESERVED! MORE About Color! Lesson Four! Seeing Color/Color Constancy! light is different. Light causes highlights and shadows, and these highlights and shadows hold colors that are not merely white and black. Artists have studied the colors of shadows for centuries. Monet, considered the first artist to articulate colored shadows, (Cytowic) worked at writing a formulaic approach to them. He was in essence, very much a scientist as he painted on the cathedral of Notre Dame at different times of the day trying to quantify the change in light with paints, to create an impression. Following Monet, the Pointillists used the power of juxtaposition to create the illusion of a single color. ! In colored shadows, “identical spectral distributions appear different; the same stimuli looks different (colored shadows) or different stimuli look the same (color constancy).” (Cytowic) The principles of color shadows is simply this: All shadows of any object, no matter what color will be a different color than the lighter side. Not only will the color be darker in black and white values, but the shadows will have color toward the complement of the lighter side. !Simultaneous Contrast! All colors we see in nature are dependent upon their surroundings. We know that colors can appear to be different depending upon their juxtapositions. Certain color combinations play tricks on our eyes. The French Chemist, M. E. Chevreul, took the learnings of Newton’s color theories and expanded greatly upon them. He is credited with eliminating indigo from the light spectrum and listing the subtractive and additive properties of light as we know them today. Chevreul also discovered many interesting things about color and is recognized with developing the Simultaneous Contrast Law: “When two tones of the same color are juxtaposed, the light color will appear lighter and the dark color darker.”1 ! Simultaneous contrast can be described as the way in which the differences in colors (see below) are intensified by juxtaposition. The value of a color can appear to increase or decrease because of simultaneous contrast. For instance complementary colors, placed side by side will appear to intensify each other and warm colors !will appear warmer when placed next to a cool color. © 2015 Cheryl Machat Dorskind ! www.cherylmachatdorskind.com! All Rights Reserved! Page #"4 © 2015 Cheryl Machat Dorskind! ALL RIGHTS RESERVED! MORE About Color! Lesson Four! Seeing Color/Color Constancy! Complementary colors appear more intense when placed side by side. According ! to color theories, colors harmonize best when their areas are in inverse proportion ! to their relative brightness. Goethe, a color enthusiast, claimed that red and green were equally bright so that when combined in a one to one ratio, the picture would ! be in balance. ! Orange is twice as bright as blue, so the ideal combination is one to two © 2015 Cheryl Machat Dorskind ! www.cherylmachatdorskind.com! All Rights Reserved! Page #"5 © 2015 Cheryl Machat Dorskind! ALL RIGHTS RESERVED! MORE About Color! Lesson Four! Seeing Color/Color Constancy! ! Yellow and violet are at extremes, and the ideal combined ratios is one to three !After Image! Along with the discovery of the Simultaneous Law, came another color discovery known as “After Image” or “Successive Contrast," whereupon each color evokes the visual complement of the other to further change its appearance. 2 For instance, if you stare at the red icon (next page) on the left for thirty seconds, and then turn your gaze to the white diagram, a green “after image” will appear in your mind’s eye. In other words, a color will take on the visual complement of the other. © 2015 Cheryl Machat Dorskind ! www.cherylmachatdorskind.com! All Rights Reserved! Page #"6 © 2015 Cheryl Machat Dorskind! ALL RIGHTS RESERVED! MORE About Color! Lesson Four! Seeing Color/Color Constancy! ! We have learned from Chevreul that prolonged staring at any saturated color fatigues the receptors in our eyes, which then compensates when resting and produces the color’s complement as a ghostly after image. Summarizing Chevreul’s findings, Christopher Dresser declared in his Principles of Decorative Design, “No one color can be viewed by the eye without another being created. Thus, if red is viewed, the eye creates for itself green, and this green (in the mind’s eye) is cast upon whatever is near.”3 ! Many other optical rules came out of Chevreul’s discoveries and his findings greatly influenced the Impressionists, Cubists, and Realists of the 19th and early twentieth centuries.
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