Top-left lighting is an artistic convention in which illustrations are produced so that the light appears to come from the top left of the picture.
Most people prefer lighting from the left when resolving a convex-concave ambiguity, and this preference is stronger for right-handed people. This is reflected in Roman mosaics and in Renaissance, baroque and impressionist art.[1] In cartography, the predominant custom of placing the shadow on the right-hand side of hill profiles was established during the 15th century.[2] Computer interfaces tend to use top left lighting as well, although this trend has gradually shifted more towards light coming straight from the top.