Gimp Interface Magic

Wallpapers 11 Gimp projects: unique effects, easily adaptable solutions, time-saving techniques and practical applications. The projects are fully customizable presented in an easy to follow format that takes you on a step-by-step ride to rediscover your creativity.
You can download a sample version of the book from here.
The full version of the book is available from Lulu.

Friday, March 09, 2007

The Magic of Simultaneous Contrast

The purpose of this article is to introduce the reader to the idea of simultaneous contrast and to the amazing effects of color interactions. Color is the single most important tool that artists and designers used throughout the ages to beautify their environment. But to use color effectively one has to understand its basic functions, its psychological and visual impacts on the environment.

Color can be approached in a variety of ways. Artists use color to give expression to their stylistic innovations. Researchers, analyze its optical qualities and its impact on the perceptual apparatus.

Op Art integrated these two components into a unique style that became very popular during the 1960s. Op Art drew its unique style from geometric designs based on the interplay of colors and the principle of simultaneous contrast. One of its most famous representative was Victor Vasarely, the Hungarian born French painter whose works are on display in the great museums of the world.

The term simultaneous contrast was coined by the French colorist M. E. Chavreul; his most influential book on the subject, The Principle of Harmony and Contrast of Colors went into production in 1839 and even today it remains an important source of information on color combinations. In this pivotal treatise Chavreul described simultaneous contrast as follows:

"If we look simultaneously upon two stripes of different tones of the same color, or upon two stripes of the same tone of different colors placed side by side, if the stripes are not too wide, the eyes perceives certain modification which in the first place influence the intensity of color, and in the second, the optical composition of the two juxtaposed color respectively. Now, as these modification make the stripes appear different from what they rally are, I give to them the name of simultaneous contrast of colors: and I call contrast of tone the modification on intensity of color, and contrast of color that which affects the optical composition of each juxtaposed color."

More than a century later, in 1963, Josef Albers' research confirmed Chavreul's findings in his monumental work The Interaction of Colors, "In order to use color effectively it is necessary to recognize that color deceives continually." and "Experience teaches that in visual perception there is a discrepancy between physical fact and psychic effect." Albers says.

Below, the reader will find examples of these principles. But before, let's take a look at the idea of the afterimage.

Here is the definition of afterimage, "It is the visual impression that remains after the initial stimulus is removed. Staring at a single intense hue may cause the cones, or color receptors, of the eye to become so fatigued that they perceive only the complement of the original hue when it has been removed."

Look at the following figure

Stare at the center of the red star for about 20 seconds then look steadily the small black dot in the white field. You should see a blue-green equivalent of the red star (blue-green is the complementary of red) The blue-green is the afterimage.

Afterimage is an optical effect that intimately bound up with color combinations.

Now, look at the following image.

The illustration demonstrates an aspect of simultaneous contrast of brightness; if a lighter tone is placed next to a dark one (the light gray star in the black field) the lighter value appears lighter; if the darker tone (the light gray in the white field) placed in a lighter field, the darker tone appears darker. Do you see the difference? Both gray stars have the same value but the one in the black area looks lighter.

If a color and a neutral gray placed side by side the gray will appear tinted with the opposite (due to the influence of afterimage). Look at the figure below and notice the violet tint of the gray circle where overlapping the yellow field. This color shift is caused by the violet that is the complementary of yellow.

If two colors are juxtaposed or overlap each other, each color influences the other. In the following image compare the left side and the right side of the blue circle. Where the circle overlapping the green area it looks more purplish. The color shift is caused by the complementary of green (which is red).

But what happens if two complementary are juxtaposed or placed one within the other? They enhance the intensity of each other. Look at the figure.

When different values of the same color is juxtaposed we get the "fluted" effect. Look at he illustration below and notice the edges where the values meet.

The image shows the transformation of flat colors into 3d effects.

The examples above show some of the optical effects derived from the basic rules of simultaneous contrast. But there are much more to this. The most effective way to learn about the interaction of colors is to experiment. In The Interaction of Colors, Albers recommends using color papers for experimenting. Today, graphic software can serve the same purpose. Programs such as Photoshop, Illustrtor, the Gimp, Inkscape are just a few of the available digital tools that can be used to explore the magical world of colors.

I conclude this article with an experiment described by Albers in his book mentioned above.

Look at the illustration below and try to guess whether the two small brown squares in the middle of the blue and orange fields have the same or different values.


Recent Posts