No one can argue that Metropolis is a visual masterpiece. Considering the time period in which it was filmed, the special effects are astounding. There were no computers to create these effects, so they were created by hand, through simple editing, or within the camera by cinematographer Karl Freund. For example, the realistic miniatures are the handiwork of Eugene Schufftan, whose eponymous technical process was eventually adopted in the United States. No optical printing existed in the 1920s, so to create a matte effect, a large mirror was placed at an angle to reflect a piece of artwork while live footage was projected on to the reverse. In order to expose the projected footage, the silvering on the back of the mirror had to be scraped off in strategically appropriate places. One mistake ruined the mirror and the whole image. This process had to...