I asked Adam to register and comment on this thread. I notice the cloudes making the sun skip in portions. Bob I am sure you read the original post. It seems to be photographic paper exposed in a pinhole camera not developed but scanned then photoshopped to invert the white to black. I would be interested to hear more from Adam on the subject. He is really good at doing fun science stuff on a almost zero budget. He did some really interesting pulsed holograms on a very low budget. (This would normally require a $40,000 laser!)