Movie makers use this aspect of saturation all the time in order to convey particular feelings. The visual element of value or tone is, in its simplest form, the juxtaposition of light and dark. It is defined as the intensity of lightness or darkness in anything that is visible. In nature there are hundreds of different steps in value that are sometimes not easily distinguished by the human eye. In the graphic arts and photography, however, there are far fewer steps because they are simply to subtle to perceive visually.
Images derive a simulated natural tone from pigment, paint, or nitrate of silver.
Thirteen steps in value have been identified, which range from white to black. These steps are based on a tonal scale, which defines the variations of shading. The element of value is used to express emotions, form, space, and movement as well as to give off the illusion of light. Since the scale for value is so limited in two-dimensional images, it is implied through several techniques. The juxtaposition of elements within a work determines value.