NewTek tricaster advanced edition, User Manual, Page: 311 / 339

Page | 295
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 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? One trick is to
‘Genlock’ your cameras to the TriCaster output (see Sections Section 3.5, Section 3.13 and 8.2.3). 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 8.1.1.
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.)

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.)

Certain projectors provide a ‘low latency mode’ to disable features of the unit that carry a heavy toll
in latency. Enabling this mode can make positioning the projector slightly more challenging (as you
may sacrifice some ability to position and scale the image using projector menu functions) – but the
latency reduction can be very worthwhile.

Some cameras include features that add more latency than you would expect. For instance, image
stabilization (by definition) adds one field of latency and sometimes more. Disable anything of that
sort that you can.

Latency may be slightly lower for progressive sessions, so for lowest latency, (genlocked) 720p
cameras and session are theoretically ideal (again, for genlocked sources, consider disabling
TriCaster’s Frame Sync – see Section 8.2.3).