In film, flashbacks depict the subjective experience of a character by showing a memory of a previous event and they are often used to "resolve an enigma". Flashbacks are important in film noir and melodrama films. In movies and television, several camera techniques, editing approaches and special effects have evolved to alert the viewer that the action shown is a flashback or flashforward; for example, the edges of the picture may be deliberately blurred, photography may be jarring or choppy, or unusual coloration or sepia tone, or monochrome when most of the story is in full color, may be used. The scene may fade or dissolve, often with the camera focused on the face of the character and there is typically a voice-over by a narrator (who is often, but not always, the character who is experiencing the memory).