In the second part of the article, I will discuss the interaction of light and environment in terms of colors.
Ewald Hering, the German psychologist said, "Seeing is not a matter of looking at light waves as such, but of looking at external things mediated by these waves; the eye has to instruct us, not about the intensity and quality of the light coming from external objects at any one time, but about these objects themselves."
In other words, we don't have to look at the light source to know about the illumination level, because we sense the level of illumination from the appearance of things in the field.
So how do we perceive the color of our environment under varying lighting conditions?
Here are a few pointers that can be helpful.
1) Color is both external and internal (mental) phenomenon.
2) In dim light red looks like black and colors, in general, become achromatic.
3) Illumination creates and destroys space; expands under bright light and contracts under dim light.
4) Effects of distance blend colors and values into medium gray.
5) There are warm colors (red, orange) and cool colors (blue, green); worm colors have the tendency to dominate.
6) Under bright light color shifts upward, toward yellow (red becoming orange); under dim light colors shift toward violet (red becoming more purple, blue more violet)
The artworks below demonstrate some of these principles; they show, in color, the same four effects I introduced in the first part of the article.
As before, the four figures illustrate the effects of normal illumination, dim illumination, atmospheric mist and luminosity.
At normal light colors seem "genuine". The figure shows a range of colors placed on a black background. The white stripe persists. Brightness and contrast are maximum.
At dim light colors have the tendency to blend together. Genuine colors don't appear, they become muted. The background is purple.
Atmospheric mist and aerial perspective is achieved by muted colors. The background is light purple. As the colors become more distant they become lighter in values. 
Luminosity is similar to atmospheric mist except that the background has a lighter value.
In the next insertion, I will continue my exploration of colors by examining the mysteries of simultaneous contrast that is one of the most interesting phenomena in color theory; so stay tuned.
Gimp Interface Magic
You can download a sample version of the book from here.
The full version of the book is available from Lulu.
Wednesday, February 28, 2007
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Studies in Illumination II |
Saturday, February 24, 2007
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Studies in Illumination I |
The following explorations in illumination effects have been based on Faber Birren's ground-breaking research in color theory. Birren summarized some of his findings in a book called Color Perception in Art that was an instant success among artists and designers all over the world.
The study of the interaction of light and surfaces revealed a great deal of new information that was only intuitively understood before; these insights gave a new tool for artists and designers that became especially evident in the genre of Op art. The role of light and color in visual design are such important issues that I think every graphic artist should know about them; my hope is that the opensource art community will find these ideas useful.
The images below are black and white studies that I have recreated from the published examples by following closely the instructions of the author. The four figures illustrate the effects of normal illumination, dim illumination, atmospheric mist and luminosity. A matching series of color examples will follow shortly.
In the upcoming weeks and months, I will explore additional issues in color theory and composition that will further expand the current topic; so stay tuned.
Normal illumination: hues and values seem "genuine". The figure shows a range of gray shades from center white to black, placed on a white background. Brightness and contrast are maximum.
Dim illumination portrayed as black and white with five steps from white to deep gray. The background is dark gray. As the illumination grows dim all dim values blend together. Genuine colors don't appear, they become blackish and muted. 
Atmospheric mist and aerial perspective is achieved by a series of grays including white.The background is light gray. As the chromatic colors become more distant they become more grayish.
Luminosity is achieved by similar techniques as atmospheric mist except that the background is medium gray.
