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B.3.4, Other sources of latency – NewTek TriCaster 8000 User Manual

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TriCaster’s portion of the total latency sum is well within acceptable standards for
devices of this sort – roughly between 1.5 and 2.5 frames (the actual amount can
vary slightly within this range, depending on several factors).

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
predece

ssor 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? One trick is to ‘Genlock’ your cameras to the TriCaster output (see
Sections Section 3.6, Section 3.14 and 8.1.2). This allows TriCaster to bypass its
input time-base correctors, ensuring latency is consistent during switching
operations. For genlocked sources, consider disabling TriCaster’s Frame Sync – see
Section 8.2.3.

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 LATENCY

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:

If you use Multiview 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.)

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