The Painting Style Called Sfumato
Leonardo da Vinci declared that nothing in nature has precise mathematical lines or borders. This sounds idiotic. In his biography of Leonarda da Vinci , Walter Isaacson says that the statement was based on a “Leonardesque blend of observation, optics, and mathematics”. A line is of invisible thickness, ergo it followed that boundaries in nature must really be blurred. This was the origin of the sfumato , the technique of using hazy and smoky outlines in paintings. Leonardo came to this conclusion via his study of optics. He wrote: “If all the images which come to the eye converged in a mathematical point, which is proved to be indivisible, then all the things in the universe would appear to be one and indivisible.” Rather, he (almost) correctly said: “The visual faculty does not occur in a point; it is diffused throughout the pupil (actually the retina) of the eye.” He came to this conclusion by moving a needle closer and closer to one eye. No matter how c...