The greatest challenge faced ny photographers and cinematographers when shooting on location is predicting where the sun, moon or stars might be at any given moment, to create the best visual effect. It's a time critical process, to be in exactly the right place, at exactly the right time. It might be predicting where the sun will set behind a wide shot of Manhattan on a particular day... It might be planning when to shoot the moon so it perfectly backlights the ocean... It might be to…