This instrument was developed to be used in bright light [hence the name Lat: "light room"] and was a much more portable alternative to the camera obscura, although the camera lucida demanded greater skill in use.

   David Hockney's claims that artists from the past, and Ingres in particular, extensively used the camera lucia were first published in the New Yorker in January 2000. 1 Because a search of the Web for "camera lucida" gives this site, Hockney's unsubstantiated speculations had the consequence of flooding me with email requests for information on the camera lucida:- where do you get one? how do you make one? how do you use one? how much do they cost? etc. To stem this tide, I added information to my Image Analysis site which outlines the principles of operation of the camera lucida along with diagrams of the instrument in use. Nevertheless I have still received a constant stream of email, increasing recently with the publication of Hockney's book ."Secret Knowledge; rediscovering the lost techniques of the old masters”, 2001 (Thames and Hudson). In the earlier introduction which this replaces I rather provocatively used the word "silly" to describe Hockney's claim that Ingres used a camera lucida. This upset several of my correspondents who questioned my right to contradict Hockney. One of these objectors told me that I should recognize that Hockney has rewritten the history of art with his discoveries; although the same person did tell me that I should be aware Vermeer used a camera lucida - a truly amazing feat considering the instrument was invented several hundred years after Vermeer's death. As things have turned out, I am sorry I used the term "silly" to describe Hockney's claim about Ingres because I should have reserved this assessment for some of the claims, logic and inclusions in Hockney's book. Just when we though art history had been freed of timelines, genealogical trees and convoluted diagrams of influence, Hockney produces one of the most bizarre diagrams yet seen. A red line, straight and true, represents the lens-based image and a meandering green line represents the "eyeballing" (sic.) tradition. As might be expected when both lines hit 1970 they break up and fly off in all directions like a beetle on acid. (pp. 184/5)

In September 2000 I had the opportunity to compare Hockney's series of camera lucida drawings of security guards with works by Ingres as they were hung together in the National Gallery in London as part of the Encounters exhibition. Such a comparison is instructive as it seems to contradict Hockney's claim that the drawings are technically similar. The drawings by Hockney have the tentative, stop-start quality of a camera lucida drawing, especially evident in the outlines or contours in Hockney's examples. There is none of this quality in the sharp, sure contours established in Ingres drawing. One was left with the immediate impression of how different the works by Hockney and Ingres were and the logical conclusion would be that if Hockney used the camera lucida, than Ingres did not. It is impossible to make such a comparison from the reproductions in Hockney's new book as he massively reduces the scale of the guard portraits and places them opposite details of pencil portrait heads by Ingres which in some cases are almost actual size (pp. 30, 31- in the T&H edition). 2 In spite of this ploy, the drawings by Hockney in reproduction retain the bland, photo-booth quality where all the bits are in the expected places and contrast so sharply with the infinite variety and subtlety of Ingres' approach which is informed not by optics but physiognomy. If the aim was to show how photographic the images by Ingres look, then even here the opposite end is achieved.

It is not surprising that Hockney could find no concrete evidence that Ingres used a camera lucida. This is because the camera lucida is not what it appears to be, especially as initially presented by Hockney. It is not an easy mechanical solution for translating a visual image onto paper. In fact, it requires tremendous skill in use and no highly competent artist or draftsperson would waste the time required to setup and use the instrument in the field when it is so much more efficient and instantaneous to sketch with eye and hand. The only place for the instrument in the kit of a professional artist from the nineteenth or twentieth centuries would be limited to accurate copying of complex contours in controlled situations. For the bread and butter jobs of preliminary sketching for landscape or portrait painting the camera lucida is pretty much useless. In fact, when versions were marketed in France in the 1920s and 30s it is clear from the illustrated brochures of the time that the target audience was amateurs hoping for a simple drawing machine. [see illustrations below]

While Hockney, in his book, does not prove his initial hypothesis that Ingres used a camera lucida he instead shifts his thesis to prove that artists generally used optical devices more than we had previously thought (or were influenced by the look of optically produced images). His "smoking gun" is the discovery of the mirror-lens or concave mirror acting as a lens (his discovery occurred on 14 March 2000 we are told in the book). Not that he discovered hard evidence of such an instrument being used but just the idea that it might have been came to him on that date. Hockney's main analytical tool is identifying drawings or paintings produced by "eyeballing." I always thought “eyeballing” was a funny colloquialism for looking at something - usually salaciously- but Hockney tells us it is “his” term for looking and drawing directly. He adds the idea that the artist ("he" always ) "gropes for the form he sees before him". All of which creates the comical image of the artist in that classic scenario of undressing someone with their eyes.

Probably the most useful and interesting material in “Secret Knowledge” is to be found in the correspondence between Hockney and Martin Kemp - as all of this and other letters and faxes from various authorities are reproduced in the last section of the book. Martin Kemp is the international authority on the intersection of optical science and art production having spent his entire career working in this area. He produced the magisterial volume The Science of Art which is the standard text. Unfortunately, it appears that when art historians enter the studio of the great painter they put their slippers on. Kemp does carefully and systematically critique most of Hockney’s claims (including the use of secrecy to explain lack of evidence) but at no stage does he put the boot in. Often, he seems apologetic for finding fault with Hockney’s ideas excusing his knowledge base and use of logic as the burden of pedantic scholarship. As to the other authorities, the tone of their correspondence is ingratiating to say the least and the enthusiasm of the optical physicist Charles Falco to support Hockney is almost nauseating. Since the overall impression is of every scholar and scientist attempting to prove Hockney right, for the sake of disinterested scholarship, we can only hope that this results from the exclusion of those who tried to prove him wrong. 3

Finally and fundamentally Hockney’s thesis is flawed by several points of simple logic. Since there is ample evidence that many painters produced, and still produce, powerful naturalistic or illusionistic images without the use of lenses any claim that a lens was used by a particular artist must be proved by evidence external to the painted image (a point alluded to by Martin Kemp). When, as he does for the book, Hockney produces an image using a concave mirror it does not look in any way like a Van Eyck portrait for example but like a Hockney done with a projecting lens - and incidently highlights how obviously many of his own early drawings and paintings were done. To prove the rediscovery of the “lost techniques” of Van Eyck would surely demand producing a painting that resembled one by Van Eyck. But even if Hockney had achieved this his case would not have been conclusively proved. This is because we are almost certain Vermeer used a camera obscura to produce his paintings but of course the Dutch forger Van Meegeren did not use any optical devices to produce his convincing fake Vermeers in the 1940s. He was in fact forced to paint a “Vermeer” canvas in a public court room. Maybe he just had an overdeveloped ability to “eyeball.”

1. Hockney's views were first outlined in: Lawrence Weschler, "The Looking Glass" The New Yorker, Jan. 31, 2000 (pp. 64 - 75) followed by a critique in: Ann Landi, "Optical Illustions", ArtNews, March 2000 (pp. 134 - 138).

2. The comparison of the Hockney guards and the Ingres portraits can be made online as they are reproduced in Lawrence Weschler's follow-up piece to his New Yorker article in Artkrush (www.artkrush.com)

Details of Hockney's book: Secret Knowledge; rediscovering the lost techniques of the old masters (published Oct. 2001 in US by Viking Studios/Penguin Putnam and UK by Thames & Hudson).

3. On the first of December 2001 the New York University, or more specifically the New York Institute for the Humanities, conducted a conference Art & Optics to discuss the theories put forward by Hockney. David Hockney and physicist Charles Falco presented their views and over two days thirty contributors responded. Included were scientists, painters, as well as art and science historians, among them: Susan Sontag, Linda Nochlin, Martin Kemp, Chuck Close, Philip Pearlstein, Michael Fried, Svetlana Alpers, James Elkins and Richard Wolheim. Selected papers have been published on the conference website: Art & Optics. At least here we have some critique of Hockney’s speculations. The papers by Christopher Tyler and James Elkins not only defeat Hockney at his own game by using overlay tracings on selected examples but use the medium of the Web (via Flash animations) to make stunningly direct visual points. All of which begs the question as to when we will see Hockney and Falco add their demonstrations to the Art & Optics website which is afterall described as a "work in progress".


By Ross Woodrow