Visual Illusions Demo

After reading other post here, it seems Simultaneous Contrast Illusion already clear, I mean its definition. Based on that I think I should find another thing to do than find another definition, which can be similar and it would be waste of time. So I decided to create a flash that demonstrate what we are going to try with both illusions, which is combining Moire Pattern illusion with Simultaneous Contrast illusion. You can find it here. I hope with this flash demo we can move on quicker.

How to emphasize simultaneous contrast in your artwork

“If you are interested in creating simultaneous contrast in your artwork, several methods help promote this effect. You can use complementary colors in their purest forms. If you do, make the shapes large enough so that the eye can see the space clearly. The eye will automatically see the afterimage, thereby intensifying its root color and the complement. You can also intensifying its root colors by using strong value differences.

To promote simultaneous contrast, you can use relatively small toned areas in the background while the foreground is made up of large, intense formations. To accentuate even further, use toned afterimage hues. This, of course, intensifies the differences between the two colors. A black background increases the drama and intensity of colors. Using the most intense pure colors, of course, will accentuate the differences.”

 

—-Joen Wolfrom. (1992). The Magical Effects of Color. C&T Publishing Inc, p29.

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Scientific approach of the simultaneous contrast illusion

 

Simultaneous contrast is a visual phenomenon in which our visual perception alters when colors are compared in different chromatic backgrounds [1]. A pioneer in the identification and study of this phenomenon was Michel-Eugene Chevreul (1786 –1889). His thorough research is presented in his book De la loi du contraste simultane´ des couleurs (The Principles of Harmony and Contrast of Colors), published in 1839.  In this book, Chevreul set the theoretical framework of the contrast, through optical experiments and applications in different domains [2]. From his research two types of contrast can be observed based on brightness[2]/luminance[3] and hue. This book influence not only the scientific community but also inspired artists, especially Eugène Delacroix who helped in the development of the Impressionism [4].

Although, a lot of research has taken place during the years, there isn’t a consolidated theory on the mechanism that creates this illusion. Different theories has been published based on different methodologies.

Edward H. Adelson in his article Lightness Perception and Lightness Illusions in The New Cognitive Neurosciences presents different theories and examples of the simultaneous contrast illusion in relation with lightness perception among with his own work [3]. He refers to Ewald Hering and Helmholtz theories and he explains different illusion experiments of his own work and of others[3]. All these examples can be seen animated in: persci.mit.edu/demos/gaz/main-frameset.html .

Regarding to the color aspect, an interesting experiment elaborated by R. Beau Lotto and Dale Purves. They approach color contrast effect with an empirical explanation [1]. Their experiment base on the ability of the subject “to adjust the perceived hue, saturation, and brightness of the right target on the achromatic surround until it matched the color of the left target” on a screen [1]. A similar approach we can see in the book Sensation and Perception [5] and on their interactive site: isle.hanover.edu/isle.html[6]. Additionally, Lotto and Purves experiment with physical surfaces and lights, and the screen. An artistic expression of this experiment we can see in the project Light and Space of Azael Ferrer (www.azaelferrer.com/#!lightspace/cu34)  [7].

 

 

 

References

[1]      R. B. Lotto and D. Purves, “An empirical explanation of color contrast.,” Proc. Natl. Acad. Sci. U. S. A., vol. 97, no. 23, pp. 12834–12839, 2000.

[2]      R. G. Kuehni, “Michel-Eugene Chevreul: From laws and principles to the production of colour plates,” Color Res. Appl., vol. 27, pp. 4–14, 2002.

[3]      E. H. Adelson, “Lightness Perception and Lightness Illusions,” New Cogn. Neurosci., vol. 3, pp. 339–351, 2000.

[4]      “Michel-Eugene Chevreul | biography – French chemist | Encyclopedia Britannica.” [Online]. Available: www.britannica.com/EBchecked/topic/109883/Michel-Eugene-Chevreul. [Accessed: 09-Feb-2015].

[5]      B. L. Schwartz and J. H. Krantz, Sensation and Perception, SAGE Publi. 2015, p. 480.

[6]      “Interactive Sensation Laboratory Exercises (ISLE).” [Online]. Available: isle.hanover.edu/isle.html. [Accessed: 10-Feb-2015].

[7]      “azaelferrer.com | LIGHT/SPACE.” [Online]. Available: www.azaelferrer.com/#!lightspace/cu34. [Accessed: 8-Feb-2015].