There are three reasons to use visual effects in a film:
- The first is when there is absolutely no practical way to film the scenes described by the script or required by the director. The astronauts’ perilous trip around the moon in Apollo 13 (1995) and thetransition of Mystique into Logan in X-Men (2000) are examples of this.
Mystique in Brain singer's X-Men (2000) - The second reason to use visual effects comes to fore when you could do the scene practically, but doing so might place someone’s life at risk. In the very first visual effect done in a narrative film, The Execution of Mary, Queen of Scots (1895), it probably would have been a bad idea to actually behead the actor portraying Mary. The 1926 silent film Fire Brigade contains a scene where a toddler gets left behind in a burning building. It is clear she is surrounded by flames and must be rescued by the heroic fireman. The little girl, however, could never be exposed to real fire. She was shot separately from the fire and the two shots were optically composited so the girl really appeared to be threatened by the flames. This technique allowed for some hair-raising scenes without risking anyone’s safety.
- The third reason arises when it is more cost effective or practical to utilize a visual effect than to film a scene for real, due to issues of scale or location (or both). Examples of this are the huge crowds of Orcs attacking in the Lord of the Rings films (2001– 2003), the little girl among the bears in Svalbard in The Golden Compass (2007), and Russell Crowe commanding his ship midstorm in Master and Commander (2003), or even the much simpler work done for Tropic Thunder (2008), with added shots of Ben Stiller having a phone conversation with his agent, long after the location was lost to the production.
