More than any other artist, he advanced the study and painting of "atmosphere". In his paintings such as the "Mona Lisa" (c.1503-1517) and "Virgin of the Rocks" (1483-1486) (the earliest complete work fully of his hand), he used light and shade with such subtlety that, for want of a better word, it became known as Leonardo's "sfumato" or "smoke". He exhibited a revolutionary use of colour by defining the transition between figures by colour modulation instead of by actual lines. His work invited the viewer into a mysterious world of shifting shadows, chaotic mountains and whirling torrents. Another significant work of Leonardo's was "The Virgin and Child with Saint Anne" (c.1503-1519); the monumental three-dimensional quality of the group and the calculated effects of dynamism and tension in the composition made it a model that inspired Classicists and the Mannerists in equal measure. Apart from the direct impact of the works themselves, Leonardo's studies of light, anatomy, landscape, and human expression were disseminated in part through his generosity to a retinue of students.