NewTek TriCaster TCXD300, User Manual

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For example, suppose a ‘video frame’ supplied by a camera arrives at TriCaster’s inputs one
millisecond after a different frame has been sent to the output. Obviously the new arrival must
wait its turn; it can’t be transmitted until the correct duration for its predecessor has elapsed.
Thus the newly arrived frame must ‘wait’ almost one entire frame, until its turn comes.
How can you achieve the lowest possible latency for the TriCaster section of the IMAG chain? To
do so, ‘Genlock’ your cameras to the TriCaster output. You can do this with any camera that has
genlock capabilities, using any model of the TriCaster.
Genlocking can be performed with suitable cameras as follows: connect TriCaster’s composite
output as the Genlock source, feeding it back to the cameras Genlock connection. Adjust the
‘genlock phase’ setting at the camera to get the lowest possible latency. This allows TriCaster to
bypass its input time-base correctors, diminishing latency by about one frame (to its potential of
just two frames.)
Hint: you can actually assess the latency of your TriCaster installation fairly easily. Run timecode
directly to 1) a monitor and at the same time 2) through the TriCaster to a second (identical)
monitor. Take a photograph that encompasses both monitors, and compare the timecode shown!
B.3.4 OTHER SOURCES OF LAT ENCY
More often than not, significant latency is added by other devices in the IMAG chain that come
after the TriCaster. Projectors are a common contributor, but at times the cameras themselves
are a factor. Here are some helpful points to consider when designing and connecting your
system:
1. If you use DVI or VGA output from the TriCaster to the projector -- if at all possible,
match the resolution sent from the TriCaster to the native resolution of the projector.
On some projectors this allows the unit to avoid using its own internal scaling, which is
often a significant factor in unwanted latency.
2. When possible, try supplying the projector with analog video. This can eliminate a lot of
the complexity from the process (of course, this is not always possible.)
3. Certain projectors provide a special ‘low latency mode’ to disable features of the unit
that carry a heavy toll in latency. Enabling this mode can make the positioning of the