[QuadList] Question for any ex-NBC types out there (Tony Quinn)

[Dennis Degan]

		On Jan 8, 2009, at 8:25 PM, C. Park Seward wrote:

 > I think the cut had to be within 2 microns to work correctly. The 
video track is 10 microns and the guard band is five so you had to be 
in the middle of the five µm guard band and on the start of the frame 
to get it all to work.

		I offer:

	The problem wasn't so much getting the cut between the tracks; that 
was relatively easy.  The problem was getting the RIGHT space between 
tracks in order to make a proper continuous frame/field sequence.  If 
you just simply cut at a vertical sync period (which appears physically 
in the middle of the tape's width), you might be cutting two field ones 
together (for example), resulting in a jump during playback.  If you 
ignored the vertical pulses altogether and simply edited together 
random video tracks, the edit may look good under the microscope, but 
will have a serious breakup during playback.  The framing pulse was 
invented just for this reason (It was not originally in the standard).  
The control track itself did not provide enough information to 
guarantee a good edit.  The framing pulse allowed the editor to 
properly match up the two sides of the edit.

			Dennis Degan, Editor-Consultant-Knowledge Bank
	  				NBC Today Show, New York