 According to Stanley Kubrick (qv) biographer John Baxter, Kubrick  decided to use the Sinar Front Projection system for the desert  backdrops during the animal/ape scenes. This method was selected  because rear projection of the desert scenes would have proved too  "murky" for SuperPanavision. The use of the Sinar system explains  why in the scene where the leopard is sitting next to the dead zebra  (in reality a painted dead horse) the leopards eyes glow a bright  color. The Sinar system used glass transparencies as backdrops;  however, the projectors necessary for this system were so hot that a  draft or a breath could crack the glass. As a result, crew members  were required to wear face masks, which started a long