NewTek 3Play 330 - Manual (Page 68)

Page 62
Among other things, genlocking permits seamless downstream integration of 3P LAY output with
other video sources locked to the same sync pulse (without requiring time base correction, which
provides a less ideal solution).
Hint: “Genlock” is an abbreviation for “generator locking”. A
professional video device often provides a “genlock input”,
which allows an external reference signal (often referred to as
‘house sync’) to control its video timing.
When video sources are connected in this manner their output
is synchronized to the reference signal, and they are referred to
as ‘genlocked’.
There is a more important reason for genlocking in a 3P LAY context, however:
Seemingly insignificant deviations in the framerate of individual cameras are common. As well, the
timing of cameras can vary slightly during use. For a single camera or short durations, this is
virtually irrelevant. However 3Play’s design involves capturing output from three cameras – small
timing variations do matter. Especially over longer periods of time, very trivial timing deviations
between sources can produce noticeable and complex synchronization issues on playback.
Serving i) 3P LAY ’s Genlock input and ii) other video devices in the chain all with the same reference
signal eliminates potential for these undesirable conditions. You could think of it this way:

Genlocking your cameras locks their output together, preventing sync issues on arrival at
3P
LAY ’s inputs and subsequent recording.

Supplying the same sync source to 3P LAY ’s Genlock input during live sessions ensures a
match between 3P LAY output and downstream video devices required to handle both it
and other (genlocked) sources.
VERT POSITION, HORIZ POSITION AND PHASE
Locking all devices to house sync is important, but this alone does not actually ensure a perfect
downstream match. Consider an army marching along: each step the soldiers take occurs at
precisely the same moment, so we could say their timing is synchronized. Even so -- if one soldier
leads with the left foot while everyone else is on the right, problems result. Or perhaps everyone
is evenly spaced and perfectly aligned but for one misfit who is badly out of position.
Figure 43