Range of brightness between the lightest and darkest portions of an image (difference between darkest and lightest parts of a picture); also a video display control that adjusts the white level and through this increases or decreases contrast. Contrast is a difference, or more specifically a degree of difference, between two things. n a video display, when contrast is set too low there is not enough difference between light and dark portions of the display resulting in a picture that is overly dark and lacking in detail. When the contrast is set too high, the light areas of the picture are faded and washed out resulting in an image lacking shadow and depth. hink of contrast as the difference between the black text and the white background onscreen or in a book. If this contrast was set too low, the white would appear gray and the letters would not stand out properly. If the contrast was set too high, the black lettering would appear gray and washed out creating a poor image.