Practical effects are visual effects used in filmmaking created by the use of three-dimensional models or figures. They are recorded by a camera rather than created by software — as opposed to computer-generated imagery (CGI).

At the time of production (1984) CGI effects were not a consideration for the film because the idea of digitally inputting a character or background was so far off it was not conceivable.

In the 1980s, the Cinematographer had to work closely with the Visual Effects Supervisor to ensure that all visual aspects of the film could be composited together. If a scene wasn't shot as planned, it could disrupt the VFX process and vice versa.

Re-shoots were extremely expensive and avoided at all costs!