The Rijksmuseum | Documentation “Philip Steadman, 'Allegory, Realism, and Vermeer's Use of the Camera Obscura', Early Science and Medicine, jrg. 10, nr. 2, Optics, Instruments and Painting, 1420-1720 Reflections on the Hockney-Falco Thesis (2005), p. 287-313: 292-293, afb. 4”