TC2 720-60 vs 1080-30 Latency

angoliam

Member
I just ran some tests using a 720/60 project with one camera set to 720/60 and the other set to 1080/30. The camera set to 720/60 did very slightly better. The latency to the i-mag screens acceptable. However that changes when I set to 1080/30. There was noticeable latency to the imag screens.

What is the native resolution on the TC2?

I would think that a system that can do 4K should be able to tighten up the latency with the 1080 signal. Is this something that is being worked on in engineering?
 

kanep

NewTek SE
The native resolution of TC2 is what you set the session to.

Typically, higher frame rates will have lower latency (as each frame takes less time through the system). So it would not be unexpected that 720p60 would be faster than 1080p30.

When you scale a source from one resolution to the other, that is going to add latency, there is no way around it. You need to receive the entire frame, scale it then sent on. If latency is important, you should set everything to the same format and avoid format conversion when possible.

The above rules are not absolute, there will be exceptions, it all depends on the devices being used and how they operate. The device that typically has the largest effect on the latency (and it often overlooked) is the output device itself.
 

angoliam

Member
Thank you for responding Kane. Since the test was done with the same gear, I would assume that all things are equal. I tested with our Panasonic PT-RZ970BU projectors at both 720/60 and 1080/30.

Are you saying that a 720/60 session will have the same low latency as a 1080/60 session? I did not test that. And if so, does that hold true for the TriCaster's higher resolutions?

However I did test our Sony PMW-400 cameras with one set to 720/60 and one set to 1080/30 on both the 720/60 session and the 1080/30 session. In the 720/60 session the camera set to 1080/30 was just slightly slower. No noticeable difference during the 1080/30 session.
 

kanep

NewTek SE
Typically, a higher frame rate will decrease latency, but nothing is an absolute, you really need to test with all of gear in the chain to see what the end result will be.

As a starting point, I'd recommend the highest frame rate possible using a progressive video format and have all devices using the same format. Then start testing from them there.
 
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