Dust and film scratch effects can add a classic touch to a film scene. This overlay effect re-creates hair, lint, scratches, spots and lines that once appeared on film, after it had been processed. Some film overlay effects can include vignettes, which were commonly used in earlier films of the 1900s. Extra grain, speckles and grayscaling are also included in most film overlays, and add a classic style to a re-created scene.
Color overlay effects can set the tone for a specific scene. A movie scene that was shot during the day can be turned into night using a dark color overlay. A club scene can be enhanced using red or green color overlays to saturate indoor lighting. Scenes can also be color corrected using color overlay effects. Scenes shot during dusk may be too yellow and warm. Adding a cyan color overlay can cancel out the yellow shade and create colors that are true to life.
Pyrotechnic overlay effects can create explosions in an action film that may be too dangerous or expensive to create on set. Pyrotechnic overlays can add a surreal effect to a mystical movie, with fireballs being released by human hands or fireflies flying in an afternoon sky. Real pyrotechnics can only be created by professionals. Firefighters and police must also be hired to be on hand in case something goes wrong. Video overlay effects eliminate that need.
Pixelating overlays are a simple effect that can be used to anonymize certain subjects. The identity of a person, who is being interviewed for a documentary, can be blurred with pixelating effects. Pixels range in size from large to small. Commercial consumer products, such as cereal boxes or a company logo, can also be pixelated to make it unidentifiable, preventing infringement of copyrighted brands.