The book was written in the 70s, and from today's perspective, makes fascinating reading. Johnson writes of a time when special effects were totally analog. The movies he cites are mostly from the 50s and 60s, with a natural bias towards science fiction. For it was those which entailed the greatest need for special effects.In the entire book, there is nary a mention of computers. It all had to be done by hand! Like hanging miniature models by near-invisible wires, to move them around on the screen. Today, such things would invariably be done in a computer.