Modern demonstrations: Problems with method, illumination, drawing vs. painting...

I am aware of just three modern demonstrations in which Mr. Hockney recorded an image according to the methods he and Mr. Falco propose: a) a portrait reminiscent of van Eyck's "Portrait of Cardinal Niccolò Albergati" done in Los Angeles (pp. 74-77), b) a portrait done in a shop front beside a town square in Italy, and c) a hypothetical "re-enactment" of the creation of Caravaggio's "Bacchus." The last two appear in Mr. Hockney's BBC documentary. All three, and d) the mirror setup at the New York symposium, are misleading in a number of ways and give little evidence in support of the theory.

The first major consideration is illumination. In a) and b), the subjects are illuminated by direct, bright sunlight. Because our eyes are sensitive to such a wide range in intensities, we are normally not aware that such direct sunlight is 10000 times more intense than illumination at dusk, and 50000 times more intense than typical artificial illuminators of the fifteenth century such as a candle a meter or two away, as Mr. Hockney and Caravaggio scholars remind us were used by Caravaggio.

A minor but related problem concerns the mirror itself. In a), b), and c), the mirror Mr. Hockney uses is larger (I judged the diameter to be roughly 10 cm) than the one they claim (p. 56) was used in paintings such as Lorenzo Lotto's "Husband and wife" (diameter 2.4 cm). Because the area of a mirror, and thus the amount of light it collects, depends upon the (mathematical) square of the diameter, the modern mirror captures (10/2.4)² = 17 times as much light as the mirror purportedly used by Lotto. All these facts suggest that the modern demonstrations yield images somewhat brighter than would have been available to Renaissance artists. What did artists do on overcast autumn or winter days in the Netherlands?

In c), and d) the illumination is with a theatrical spotlight containing its own concave mirror reflector to increase the intensity plus a ridged Fresnel lens (invented in 1822 and familiar from lighthouses). This kind of illumination is both bright and collimated and thus produces sharp shadows that are helpful when tracing a projected image. But if Caravaggio used artificial illumination, as stated in the direct quote of Mr. Hockney, above, the numerous candles or oil lamps would not have given sharp shadows.

Another concern is that in a), b) and c), my Hockney traces the image, rather than paints directly (see particularly p. 76). He later turns the tracing rightside-up and hatches using a pencil. As far as I know, the vast majority of the "optical" paintings of the Renaissance that the theory purports to explain have no such thin line drawings as underdrawings. (Modern infra-red photography would reveal line underdrawings, if indeed they exist.) A few have painted underdrawings. Painting over projected images is very difficult (I and several of my students have tried it). For instance the red pigment you apply appears the wrong color under the colored light of the projection itself. Thus if the artist makes the color he applies look correct, then the color will look incorrect when the final painting is hung on the wall and illuminated normally. The simplest way to try to avoid this is for the artist to judge color while looking at the subject, not at the projection -- an awkward and unlikely way to capture the subtleties of color and surface in such paintings, switching moment by moment between the bright illuminated object and its dim inverted projected image. In short, the relevance of Mr. Hockney's black and white pencil tracings to the colored paintings (having no such pencil underdrawings) he seeks to explain is tenuous.

The entire discussion about the Hockney/Falco theory would be advanced signficantly if someone were to do what is accepted in other debates of which I am familiar, particularly those relating to simple inexpensive technology: attempt to re-enact as faithfully as possible the methods that are claimed by the theory. This means, for instance

• using a mirror such as Hockney and Falco infer for Lotto's "Husband and wife" (f = 54 cm, diameter = 2.4 cm)
• painting areas (not tracing outlines), since as far as I know infra-red photography has revealed no pencil or other sharp outlines in the underdrawings of the vast majority of "optical" paintings in fifteenth-century Europe
• use a canvas the size of the original, such as the Lotto (96 x 116 cm) or Caravaggio's "Supper at Emmaus" (141 x 196 cm), the latter portraying figures at nearly life size
• use no electricity or modern illumination whatsoever, and be as faithful to constraints upon illumination that we know, for a Caravaggio that means working in a dark room such as a cellar

Unless and until someone steps up to such a task, I suspect many observers will remain skeptical of the theory.

Such a faithful re-enactment would be an excellent first step, and allow us to then turn the many other problems that surround the theory, such as whether the technology was in fact available, why we find no convincing corrorboratory records, whether the method leads to more "optical" paintings or is in any way preferable to traditional methods, and so on.

Summary: There are many problems with the modern demonstrations of the projection method, including bright artificial illumination with Fresnel lenses. Most importantly, all demonstrations I am aware of address marking (tracing) lines rather than rendering surfaces. Thus the modern demonstrations do not illustrate how the vast majority of "optical" paintings with no outlined underdrawings were made.