The Incredible Shrinking Man is a 1957 science fiction film based upon the novel `'The Shrinking Man'' by Richard Matheson, and adapted for the screen by Matheson.
The film's hero is contaminated by a radioactive cloud, and begins gradually shrinking. Throughout the film the hero continues to get smaller; for a time he finds some companionship with midgets, but continues to shrink, eventually reduced to living in a dollhouse. After nearly being killed by a cat, he winds up trapped in the basement and engaged in a life-and-death struggle with a spider. The camera work and effects for the shrinking hero were considered remarkable and imaginative for their time. (The drops of water dripping from the boiler near the end of the film were actually created using water filled condoms; the consumption of large numbers of these raised eyebrows amongst the film company's accountants).
Having defeated the spider, the hero accepts his continuing accelerating shrinkage, and looks forward to see what waits for him in the realms of the ever smaller.
The theme of size-changing was explored in several other movies of this period. The Amazing Colossal Man (1957) dealt with male growth, while Attack of the 50 Foot Woman (1958) explored the idea of female growth. The fourth permutation (female shrinkage) eventually appeared in 1981 with The Incredible Shrinking Woman.
