Stock footage, and similarly, archive footage, library pictures and file footage are film or video footage that is not custom shot for use in a specific film or television program. Stock footage is of beneficial use to filmmakers as it is far cheaper than shooting new material. Examples of stock footage which might be utilised are moving images of cities and landmarks, dangerous wildlife in their natural environments and historical footage.
Stock footage can also be used to integrate news footage or notable figures into a film. For instance, the Academy Award-winning film Forrest Gump used stock footage extensively, modified with computer generated imagery to portray the lead character meeting such historic figures such as John F. Kennedy, Richard Nixon, and John Lennon.
One of the largest producers of public domain stock footage is the United States government. All videos produced by the United States military, NASA, and other agencies are available for use as stock footage. There are a number of companies that own the copyrights to large libraries of stock footage and charge film makers a fee for using it, but they rarely demand royalties. Stock footage comes from a myriad of sources; including the public domain, other movies and television programs, news outlets and purpose-shot stock footage.
News programs use film footage from their libraries when more recent images are not available. Such usage is often labeled on-screen with an indication that the footage being shown is stock footage.
Television and movies series also often recycle footage taken from previous installments. For instance, the Star Trek franchise kept a large collection of starships, planets, backgrounds and explosions which would appear on a regular basis throughout Star Trek's five series and ten films, being used with minimal alteration. This kept production costs down as models, mattes, and explosions were expensive to create. The advances in computer graphics in the late 1990s and early 2000s helped to significantly reduce the cost of Trek's production, and allowed for a much wider variety of shots than previous model and painting based visuals.
Some series, particularly those made for children, such as Teletubbies, reuse footage that is shown in many episodes. For a young audience, increasing familiarity. This introduces problems such as the requirement to, for example, wear the same clothing and inconsistency can sometimes become a problem. When cleverly filmed it is possible to avoid many of these problems.
Stock footage is most often used in commercials when there is not enough money or time for production. More often than not these commercials are political or issue oriented in nature. Sometimes it can be used to composite moving images which create the illusion of having on-camera performers appear to be on location. B-roll is also another common term for stock footage and is used in reference to film making.
Suppliers of stock footage fall into two categories; rights-managed and royalty-free. Many websites offer direct downloads of QuickTime clips, the standard now in use for NLE applications.
Source: Wikipedia
