The illusions used in the film industries are called special effects. These are used to simulate the imagined events in a story.
Special effects are traditionally divided into the categories of optical effects and mechanical effects.
-Optical effects are techniques in which images or film frames are created photographically.
-Mechanical effects are usually accomplished during the live-action shooting.
Here there are some examples:

OPTICAL EFFECTS

MECHANICAL EFFECTS
Special effects began to be used at the beginning of the 80s. One of the first productions with special effects was "The young Sherlock Holmes", and then "King Kong".But, doubtlessly, one of the best films with special effects is AVATAR.
Avatar is an American science fiction film written and directed by James Cameron.
The story happens in the year 2154, when Jake Sully is turned into an avatar and is moved to Pandora. There, he and the others scientists investigate the Na'vi, the habitants of Pandora, and Jake falls in love with Neytiri. Jake tries to save the Na'vi because the scientists want to destroy Pandora.
It is also one of my favorites films.
Now, what about you?:
-What is your favorite film?
-Do you thing that special effects are a great technological advance?
