Before talking about special effects in the films of the 1930s and the 40s, it would be interesting to know where was exactly the development of FX techniques at the late 20s.
Actually, American film making flowered in the 1920s. Film makers began to branch out beyond the artistic and technical boundaries established by the pioneers of the previous decade, and relied increasingly on special effects. The first studio departments dedicated to the creation of special effects were created at this time. Either way, the term “special effects“ received its first screen credit in the 1926 Fox picture What Price Glory ?
The 1920s knew the beginning of the wide-sprayed use of small models in the film making industry (models, objects or locations that were too big, expensive or impractical to be filmed in any other way). At this time, Hollywood was the world’s leading film factory, but the special effects of German film makers, with their mechanical expertise, was technically far superior (particularly the ambitious and expensive productions directed by the German film maker Fritz Lang).
Screenshot of The Lost World (1925), this ambitious American version of Conan Doyle’s novel used startling stop-motion animated dinosaurs miniatures created by Willis O’Brien (who will manage the special effects in the 1933 version of King Kong).
Fritz Lang’s effects masterpiece, Metropolis (1926), a visionary science-fiction fable that made stunning use of more than 200 matte paintings and models.
Thus, German films were a major influence on American film makers of the 1920s. The spectacular The Thief of Bagdad (1924) used opulent sets and the best effects Hollywood could buy in an attempt to compete with German films of the time. Moreover Ben Hur (1925) required the creation of a full-scale Circus Maximus and a fleet of seven huge Roman galleys on location in Italy. But a number of incidents — including the burning of the galleys (!) — combined with bad weather and Italian labour disputes, brought the production back to California. The film was completed rebuilt sets with significant use of miniatures.
Douglas Fairbanks on a flying carpet suspented by unseen wires above hundreds of extras on the set of The Thief of Bagdad (1924).
From off-camera, the miniature components of the arena used for Ben Hur (1925) is clearly visible. When filmed from the correct angle, the combination of full-scale set and miniature is seamless (bottom). The foreground miniature film technique used is succinctly explained by the sketch below.
The foreground miniature is exactly what its name suggests : a small model that is carefulled designed and placed in front of the full-scale film set (so their line of perspective match seamlessly together). This technique (therefore often called “hanging miniatures“) will be frequently used in the 1930s and 40s film productions.