We will explain how the mixing of paint combines elements of additive and subtractive color reproduction. The characteristics of vision explain which combinations of colors and patterns are effective, and which are not. We will review the reasons that blue exhibits poor sharpness, and show why you should avoid placing detail in blue. Visual acuity Human vision adapts over a wide range of intensities. Your viewer's impression of your work will be determined by her viewing conditions, so you must take into account the expected viewing conditions when you create your work.
Visual acuity is at a maximum only in a small portion of the visual field.
As the angle from the center of the gaze increases, acuity is reduced, but sensitivity to movement and flicker increases. To make effective use of vision in an interactive system, you must be familiar with these characteristics. Contrast sensitivity is the measure of visual acuity. Familiarity with contrast sensitivity will help you to determine how much detail you can expect your viewer to perceive. We will define contrast ratio, and explain how you can maximize contrast ratio to improve subjective sharpness.