Comparisons of video latency introduced with mixers

[jasonvincent]

Hi

I'm on the verge of setting up a system for my church which will use 2 cameras among other gear. I am looking to purchase a video mixer or comparable solution, and have been looking at the Tricaster and Datavideo SE500.

I saw a previous post where someone mentioned that using a Tricaster for live IMAG work would result in noticeable delay:

/video-mixers-and-signal-conversion/37681-anybody-using-newtek-tricaster-studio.html (I can't include the entire URL as I'm a newbie, but it's this site)

What I'd like to find out is the relative times in the latency which would result from the following scenarios:

1) 2 cameras hooked up to a simple video switch that displayed to the projection system [not what we will be doing, but may act as a reference for 'best possible latency']
2) 2 cameras hooked up to the Datavideo SE500 which outputs to the projection system
3) 2 cameras hooked up to the Tricaster which outputs to the projection system

I know it is very subjective, but has anyone got any idea of the sort of latencies we *may* see?

As you can tell from the 2 products I'm considering, like most churches I'm on a tight budget, so broadcast quality gear won't be necessary!

Why I'm worried: (I went to a church a few weeks ago and the image of the speaker, which was directly behind him, was noticeably lagging behind his speech and actions by about 1/3 - 1/2 second, and it was quite disturbing).

Many thanks

[tedanderson]

I always recommend analog equipment for this kind of setup. One common misconception is that going digitial is the best way to do things. But one thing that is often overlooked is the delay factor that results from the modulation, sampling, and demodulation.

It's just an aspect of digital that you will never be able to get away from without spending a fortune. And even some of the more expensive switchers have a little bit of lag time.

Avoid delays. Go analog.

[waynehoskins]

Ted said it before I had a chance to.

Analog is (or can be) real-time, or at least nearly real-time.
Digital is never real-time. Reality has to be sampled, processed, encoded, decoded, processed, re-encoded, and so on. By the end of it all, you're really looking back in time at things that aren't there any more.

My go-to switcher for this sort of thing would be a Grass 100N. Rock-solid analog switcher, and they're (dare I say it? I will feel old) 25 years old now, so you can find them relatively inexpensively. Echolab SE series are good too.

To not have delays, you will absolutely have to have broadcast-quality gear. Granted, broadcast gear of 20 to 50 years ago, but broadcast-grade gear nonetheless.