Religion
In reply to the discussion: Shroud of Turin [View all]okasha
(11,573 posts)I'm an (almost antiquated at this point) wet-darkroom black and white photographer. The image on the shroud, regardless of who made it when, is a photographic negative. When it was first photographed in the late 19th century, the image that appeared on the film--i.e., the "negative"--was a positive image, which means that lights and darks were distributed realistically, highlights light, shadows dark. On the shroud, the lights and darks are reversed, shadows light, highlights dark.
If it were a medieval painting, one would have to assume that someone who had never seen a negative image of a human being (or anything else, for that matter) could create a monochrome image with lights and darks precisely and correctly reversed. It's also difficult to understand why a medieval artist would paint a monochrome image at all, rather than producing a full-color painting. Since this image seems to have been known from the first quarter of the 14th century, one would also have to consider that the modelling--the treatment of depth and volume in the human figure on a two-dimensional surface--is considerably beyond any paintings known from that period. Compare Giotto, for instance.
If there is in fact an initiative to perform further tests on the shroud, I would like to see the image tested for silver salts. If they are present, one would have to assume that the image was produced by the use of the camera oscura, which was known in the fourteenth century. And then the questions get really interesting.