Historian Dan Scavone on the Da Vinci Speculation

This page is best understood by first reading the page about Understanding the nature of the Shroud of Turin's images and Argument that Leonardo da Vinci did not create the Shroud.

Historian Dan Scavone comments on the Lynn Picknett and Clive Prince argument that the image was made using a magic lantern, a simple projector, and light-sensitive chromium salts in an egg white medium.

The argument that history's proto-photo was a life- sized photo(!) on a fourteen-foot cloth(!) that was a composite(!): double corpse with daubed-on blood and, in separate processes, Leonardo's own head front and back, is a priori far-fetched. The premise is more demanding of faith than is the authenticity of the Shroud. I am led to ask why Leonardo has left us his self-portrait in red chalk and not his photo, and why he would use another body when Vasari notes that his own physique was near-perfect, and everybody knows his exorbitant vanity.

Scavone also said:

This question leads the authors to another assertion: Leonardo was a member of a secret society called the Priory of Sion, which esteemed John the Baptist over Jesus. Therefore, the apparent disembodied head visible on the Shroud man was Leonardo's cipher for the decapitated Baptist. Leonardo's use of his own photo, they argue, was owing to his inordinate vanity, the same that prompted him to encode his own face in his famous portrait of Mona Lisa, wife of Francesco de Giocondo. This theory was confirmed by Lillian Schwartz of Bell Laboratories and Dr. Digby Quested of London, who discovered that it matched up perfectly with the major lines of Leonardo's face in the above-mentioned self-portrait at age sixty. Picknett writes "Leonardo was capable of subtly building his own image into that of his masterpieces; if he had done so with the Mona Lisa, why not with the Shroud?"

On this last point, if we follow this logic, we might conclude that the Christ Pantocrator icon at St. Catherine's Monastery in the Sinai, created in 550 AD. is also a forgery and replacement by Leonardo. See the strong resemblance of this icon to the Shroud of Turin.

We know enough about the image chemistry from spectral analysis to know that the image was not produced with photosensitive chemicals.