There is nothing random about the visual field. It is inherently organized. The effect of the light is perfectly coordinated. At each point in space just exactly the right amount and color of light is present. This is due to the absolutely, mathematically consistent behavior of light. If this were not the case, if light behaved randomly, vision would not be possible. The coordinated relationships of the values and colors of the visual field, taken together, add up to a state of tonal unity, a harmonious oneness of luminosities, which we call the ‘POSTER’.
The poster study is a small, semi-abstract painting, with much less drawing and detail than a finished painting. The focus of the exercise is the general effect of the tonal harmony. We paint the poster study in a sequence of brushstrokes, beginning with the darkest and proceeding gradually up the value scale to the lightest. Each brushstroke is a ‘tonality’ possessing value, hue and intensity. Value is the lightness or darkness of a tonality, hue is its color family (blue, green, yellow, etc.), and intensity is its degree of saturation or neutrality. The tonal interaction of the various brushstrokes suggests the sensory experience of the light.
Light is energy that we see with our eyes. Light is emitted in all the colors of the rainbow. The poster study of a given scene expresses the color of the light in the space.
For painters, understanding the color of the light is essential. The color of the light is our ‘stock in trade’. Everything we paint, we paint according to the color of the light. The poster study is an ideal exercise to develop a working understanding of the color of the light. It may be helpful to read books about color. But books won’t give us experiential knowledge. For that we need to jump in. But jumping-in can be frightening. Fortunately for us, when it comes to learning about color there is a safe, non-threatening way to begin, the 'kiddie pool of color': the poster study.