Rob Legato creates visual effects for big-budget movies.
(Video link) In this TED talk, he shares how he created effects sequences for Apollo 13, Titanic, and Hugo. In the first two cases, actual documentary film footage exists of some of the scenes he was visualizing. The real footage served as a reality check against the cinematic invention.
One of the surprising revelations is that our sense of what looks real is greatly influenced by the emotional processes of our memories, which reorder reality into a composite fiction.
That emotionally tinged version of reality is what moviemakers need to bring to life if they want to create convincing illusions. The same general principle applies to painting. Often it's necessary to go beyond optical or photographic realism in order to achieve psychological realism. It's the difference between mere accuracy and true believability.
Rob Legato on TED: The Art of Creating Awe