Synchronization on DVCam process has replaced, as years go by, traditional transfer. It consists in transferring the original sound on an NLS station hard drive (AVID Media Composer, Lightworks Touch, Apple Final Cut Pro), and then, depending on rolling speed, in transferring it from that hard drive,
A) for 25 fps:
- on one hand, analogly to a "mute" DVCam tape coming from the motion picture lab (it's a perfect copy of the Digital Beta tape directly telecine-tansferred from the negative film), provided with continuous and increasing Timecode.
- on the other hand, digitally to a DAT tape (called "mirror"), on which the same Timecode has been laid down.
This DAT is thus, regarding audio data and Timecode, a true copy of the Beta SP tape which will be fed to the picture-editing workstation (NLS) and will afterwards be used for the EDL sound conformation process.
B) For 24 fps, the original sound is transferred to the NLS workstation hard drive, then transferred from that one to a "mute" DVCam tape which comes from the motion picture lab provided with continuous and increasing Timecode. However, as image transfer to video implies a 25 fps rate, sound must be speeded up (4.1666%) to preserve synchronism. For a 24 fps filming, a "mirror" DAT has absolutely no use.