special effects

Special effects

Special effects are traditionally divided into the categories of optical effects and mechanical effects.

Optical effects( photographic effects)are techniques in which images or film frames are created photographically. For example, multiple exposure . An optical effect might be used to place actors or sets against a different background.

mechanical effects are usually accomplished during the live-action shooting.This includes the use of mechanized props, scenery, scale models, pyrotechnics and Atmospheric Effects. For exaple, a car appear to drive by itself.