Lucas' Industrial Light & Magic (ILM) handled the film's special effects, under the supervision of Richard Edlund. The team worked on both "Raiders of the Lost Ark" and the dark fantasy "Dragonslayer" (1981). Lucas felt special effects were a financially economical method of delivering a good film. As long as they are emotionally involved in the story, he said audiences would buy into even a poor special effect. Spielberg liked practical effects because he could regularly check the raw footage during filming, rather than waiting months for the completed composite effects.