The use of light and dark in art is called value. Value can be subdivided into tint (light hues) and shade (dark hues). In painting, which uses subtractive color, value changes are achieved by adding black or white to a color. Artists may also employ shading, which refers to a more subtle manipulation of value. The value scale is used to show the standard variations in tones. Values near the lighter end of the spectrum are termed high-keyed, while those on the darker end are low-keyed.
Value scale
The value scale represents different degrees of light used in artwork.
In two-dimensional artworks, the use of value can help to give a shape the illusion of mass or volume. It will also give the entire composition a sense of lighting. High contrast refers to the placing of lighter areas directly against much darker ones, so their difference is showcased, creating a dramatic effect. High contrast also refers to the presence of more blacks than white or grey. Low-contrast images result from placing mid-range values together so there is not much visible difference between them, creating a more subtle mood.
In Baroque painting, the technique of chiaroscuro was used to produce highly dramatic effects in art. Chiaroscuro, which means literally "light-dark" in Italian, refers to clear tonal contrasts exemplified by very high-keyed whites, placed directly against very low-keyed darks. Candlelit scenes were common in Baroque painting as they effectively produced this dramatic type of effect. Caravaggio used a high contrast palette in such works as The Denial of St. Peter to create his expressive chiaroscuro scene.
Caravaggio, The Denial of St. Peter, 1610
Caravaggio's The Denial of St. Peter is an excellent example of how light can be manipulated in artwork.