Sfumato

'smoked off', i.e. 'blurred') is a painting technique for softening the transition between colours, mimicking an area beyond what the human eye is focusing on, or the out-of-focus plane.

Leonardo da Vinci was the most prominent practitioner of sfumato, based on his research in optics and human vision, and his experimentation with the camera obscura.

Hall,[2] which has gained considerable acceptance,[3] sfumato is one of four modes of painting colours available to Italian High Renaissance painters, along with cangiante, chiaroscuro, and unione.

[4] The technique is a fine shading meant to produce a soft transition between colours and tones, in order to achieve a more believable image.

Besides Leonardo and his followers, the Leonardeschi, who often used it heavily, other prominent practitioners of sfumato included Correggio, Raphael, and Giorgione.