I came across this, one of the nicest explanations ever:
- http://forums.creativecow.net/archivethread/27/179071#181328
- J cut, sound precedes picture. Audio before video.
- Youre still looking at a scene and the sound from the next scene begins before the cut.
- The Graduate was one of the first features to use this technique extensively to transition between scenes.
- Dustin Hoffman in his car on the freeway, sound of knocking on the door, cut to door opening at the girlfriends apartment.
- The L cut is the other way around, you still hear the sound from the previous shot but you’re all ready looking at the next shot.
- If you put a dissolve or other transition between the shots then it isnt an L cut or a J cut anymore even though the sound may lead or follow picture.
- In essence, they are a great way to extend, if not to fake, continuity when it isn’t really there.
- J cut, sound precedes picture. Audio before video.