Un Chien Andalou and L'age D'or weren't short films. According to my old college film professor, he and Luis Bu˝uel were crazy drunks who drank up all of the money that Bu˝uel's mother had given them to make the film and then had to put Un Chien Andalou together very quickly and on the cheap. Dali's sense of visual "shock therapy" made the fim as much as the plot. If you haven't seen either one, check out this opening scene from Un Chien Andalou.
Originally Posted by zsas
He also did set design for Hitchcock's film, Spellbound and worked with Man Ray in creating surrealist photography.