Hi Christine, Well there has been another program on the Shroud which looks into the possibility that Leonardo created the shroud, and that it may in fact be a self image. It seems that around the same time the pinhole box was invented which, like a camera, produced an upside down image on a cloth at the back of the box. Because Leonardo was interested in perspective, he was very interested in the box, because the image automatically showed perspective, and he probably spent many hours fooling with one, as he was also an inventor.
It was shown how egg white, urine, and a third ingredient which I can't recall, would capture a faint image on the cloth when it was exposed for many hours. These were materials that were already in use by artists at the time. It turns out that urine contains nitrates which are slightly photo sensitive. The image was fixed by holding the cloth in front of a fire just close enough to slightly scorch the fibers. When the cloth was then washed, there was a permanent negative image. There were several examples of this technique from that period. It was actually a precursor of modern photography. The pinhole has been replaced by a lens to gather more light, and the medium has been made more light sensitive, but the basics are the same.
Del |
