Visual effects (sometimes abbreviated as VFX) is the process by which imagery is created or manipulated outside the context of a live-action shot in filmmaking and video production.
VFX involves the integration of live-action footage (which may include in-camera special effects) and generated-imagery (digital or optics, animals or creatures) which look realistic, but would be dangerous, expensive, impractical, time-consuming or impossible to capture on film.
Visual effects using computer-generated imagery (CGI) have more recently become accessible to the independent filmmaker with the introduction of affordable and relatively easy-to-use animation and compositing software.
As the executioner brought the axe above his head, Clark stopped the camera, had all the actors freeze, and had the person playing Mary step off the set.
His most famous film, Le Voyage dans la lune (1902), a whimsical parody of Jules Verne's From the Earth to the Moon, featured a combination of live action and animation, and also incorporated extensive miniature and matte painting work.