Can you comment on precisely how the synchronization process works? For example, should the peak of the clapping sound ever be offset by any number of frames from the frame on which the clapper strikes the slate, and if so under what circumstances? Is there ever any ambiguity regarding the frame on which the clapper strikes the slate?
Also, in a long scene, is drift in synchronization ever a problem?
Ahhh, you anticipated my next comment. The thing I've noticed with digital video is that the audible "clap" of the clapper bars never actually seems to line up with the video as recorded on the camera. In fact, on the Canon SLRs I've shot with, the "clap" seems to happen about two frames BEFORE the bars close. Why this is, I don't know.
Drift can and is a problem with digital video, especially with sync sound. I use a program called DualEyes to replace the camera audio with the second sound in post, and that software does drift correction on its own.
USS Intrepid wrote:
Also, don't know if this is a British thing, but the physical slate I have has a space labelled 'slate'. I've never been entirely sure what the correct usage of this is, but I tend to use it as an incremental count on the number of shots we've slated throughout the day.
Nick, do you have a pic of this slate?
@doubleohfive: Those colored stripes on top are another useful feature, since they provide valuable clues to the people in post production (VFX, color-grading, compositing, ...).
Those are good to have. Frequently I tape a printed set of COLOR BARS to the back of the slate and have the Camera Assistant show that to the camera before flipping the slate around to mark the take.