Optics, Instruments and Painting, 1420–1720: Reflections on the Hockney–Falco Thesis [Early Science and Medicine Vol. 10 no. 2]

Edited by:
  • Sven Dupré
Brill Academic: 2005. 214 pp. $74 1383-7427

Readers of Nature were among the first to learn of an intriguing theory proposed by artist David Hockney. He suggested that as early as 1420 some leading European artists used concave mirrors to project optical images on to their canvases, and traced them during the execution of their paintings (see Nature 400, 524 (1999)10.1038/22937; Nature 412, 860 (2001)10.1038/35091126; Nature 417, 794 (2002)10.1038/417794a ). The claim is sometimes called the Hockney–Falco thesis to acknowledge the technical efforts of physicist Charles Falco. Hockney thinks the procedure was a key source of the naturalism, or ‘optical look’, arising in early Renaissance painting.

This special issue of Early Science and Medicine is a product of a four-day symposium in Ghent in November 2003. It is the first work to provide independent evidence on the material culture and documentary record, and analyses of optical knowledge, of the fifteenth century.

Did artists or scientists have access to suitable mirrors? Sara Schechner, curator of historical instruments at Harvard University, explores the state of optical fabrication at the time. She concludes that “Renaissance mirrors were far from offering the painter a short-cut to a detailed and naturalistic image of his subject.” Early mirrors, she argues, “could not reflect or project clear, undistorted, ‘photo-realistic’ images, as Hockney and Falco suggest.”

Renaissance art historian Yvonne Yiu of the University of Basel finds no surviving textual evidence for the procedure: “the silence of this considerable body of texts on the concave mirror projection method is deafening.” To Yiu it seems inconceivable that “well-informed contemporaries” would not have described a method that, according to Hockney and Falco, “revolutionized the art of their time”. Filippo Camerota, a historian of Renaissance scientific instruments at the Istituto e Museo di Storia della Scienza in Florence, points out that in the second half of the sixteenth century, when appropriate projections were first documented, Giambattista della Porta wrote: “If you are incapable of painting a portrait, this is a method you should know.” This is hardly support for the claim that tracing projections sparked a revolution in painting more than a century earlier.

The scientist Witelo's Perspectiva, from about 1270, has previously been used as evidence that Renaissance scientists and possibly artists knew about appropriate projections. But Mark Smith, a historian of Medieval and Renaissance optics at the University of Missouri, provides an object lesson in the importance of expert knowledge when judging such a claim. Hockney and Falco take Witelo as saying that the image literally floats in space or is somehow projected to a location outside the mirror. “What Witelo really means,” says Smith, “is that the image will be located behind the reflecting surface”. The public might have concluded that Witelo was describing a projection of a real image and hence is closely related to Hockney's method. A student of basic optics might have concluded that Witelo described a real image in space, not on a screen, and hence only distantly related to Hockney's method. But after analysing the Latin text, context and contemporary thinking, Smith argues that Witelo was describing instead a virtual image, unrelated to Hockney's method.

It seems that Hockney has recently retreated from his claim that artists actually traced projected images to a weaker view that artists merely saw and were influenced by such images. Philosopher of science Christoph Lüthy of the Radboud University of Nijmegen has read contemporary texts and concludes the former claim is “fairly implausible” and the latter “still awaits corroborating evidence”.

The volume's editor, Sven Dupré, a historian of Renaissance optics, summarizes the conclusions of the contributors. It makes the Hockney–Falco theory “extremely unlikely as far as its application for the period before the first textual reference to image projection around 1550 is concerned”, he writes.

This well-written volume may close the door on the Hockney–Falco tracing thesis. But it should also prove a good resource, especially for optical scientists lacking a background in the history of art or science, from which to explore optics in the early Renaissance.