31. Some used a dual-rotating drum slide projector that would have its own mirrors to switch between the drums. 32. A slide projector underneath flashes the advertising up onto the panel, which acts much like a movie screen. 33. The magic lantern ( Laterna magica or Lanterna magica ) was the forerunner of the modern slide projector . 34. The theater initially used the Dove X / DORK automation system for slide projectors and special effects projectors. 35. At a more advanced level, flip charts, slide projectors , and overhead projectors are more suitable for displaying prepared content. 36. Then, he stopped walking and unconsciously stood, all 1 . 88m of him, in front of a slide projector . 37. He lugged around slide projectors and huge stereo sets, and gave them a behind-the-scenes glimpse into the filmmaking process. 38. For group viewing, a polarized stereoscopic slide projector , silver screen and polarized glasses could be added to the system. 39. With the help of friendly electronic engineers, Semenoff invented a simple control system that could operate three slide projectors . 40. It consisted of two slide projectors with a rotating occluding disk that alternatingly blocked the images from the projectors.
