Wilhelm Homberg described how mild darkened some chemical substances in 1694. Leonardo da Vinci mentions natural camerae obscurae which are shaped by dark caves on the edge of a sunlit valley. A gap in the cave wall will act as a pinhole digital camera and project a laterally reversed, the incorrect way up picture on a chunk Photograpy News of paper. Renaissance painters used the digicam obscura which, actually, gives the optical rendering in color that dominates Western Art. It is a field with a small gap in one side, which permits particular light rays to enter, projecting an inverted image onto a viewing display screen or paper.
