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ATEM TV studio HD Latency

PostPosted: Tue Sep 04, 2018 2:57 pm
by stevemaster85
Hello everyone

I was planning to get an ATEM television studio HD to improve my live concert setup.

I mostly shoot baroque/classical music concerts with three cameras, one of which is connected to a projector and show the audience the main angle or something that they cannot see from their seat (e.g. the organist etc).

I have read and watch a lot about this video switcher and I was almost convinced but than I found a video showing the switcher have a bit of latency in the program out, which is a complete deal breaker for me. In the video the guy had connected the cameras via HDMI, is there any chance to have no noticeable latency by connecting the cameras via SDI by adding an hdmi to sdi converter?(at the moment I only can afford hdmi cameras).
Anyone using this switcher can confirm that?


Re: ATEM TV studio HD Latency

PostPosted: Tue Sep 04, 2018 4:43 pm
by Xtreemtec
Well all depends on your complete chain of hardware.

Semi pro cameras have about 1 to 3 frames latency, Prosumer camera's and DSLR's can easily have up to 8 frames of latency in there video.. :shock:

The Atem has 1 frame latency because of the Framebuffer. (Or 2 if you are going to use the DVE).

You screen depending on that it is.. (Ledwall, LCD's, Beamer) if any scaling is happening because the input resolution is not the Native resolution will add latency.. A beamer in most cases will add 3 - 5 frames latency!

In 50Hz every frame is 20 milliseconds 1/50=20 In 60hz every frame is 16 ms..

So to count up for example 50Hz setup..
Camera 1 to 8 frames = 20ms to 160ms
Atem 1 frame = 20ms
Screen 2 to 6 frames = 20ms to 140ms

So the Atem isn't that bad in latency.. 8-)

If you are going to use proffesional cameras that can be Genlocked to a BlackBurst or Trilevel sync you can even scratch the 1 frame of the Atem is setup correctly. Because you don't use the Frame buffer due to the Genlocked sources..
Also most proffesional cameras that will Genlock have a Latency of maximum 1 frame!!

So a lot to gain if you are going to use proffesional broadcast cameras all genlocked to a genlock generator. ;)

Re: ATEM TV studio HD Latency

PostPosted: Tue Sep 04, 2018 9:20 pm
by Thomas Seewald
Again and again the same prejudice that the latency comes mainly from the ATEM, although other parts of the signal chain cause much more latency.

Thank you Daniel for the clarification.

Re: ATEM TV studio HD Latency

PostPosted: Wed Sep 05, 2018 8:39 am
by stevemaster85
Definitely not a prejudice since I was worried about it only after seeing that happen.

By the way my curret setup is a Canon HF-G10 connected via HDMI to an HDMI to CAT converter 〉50 meters ethernet cat5 cable 〉CAT to HDMI converter and an entry level consumer Epson projector and at the moment there are no noticeable latency. Of course there are some (never actually tested how many frames/millisec) but not as much as the one I saw in the video I mentioned before.

If you say the ATEM itself brings just 1 frame more into the equation than it would be totally acceptable.

I think im going to maesure how many frame of latency I have at the moment with some slowmo.

At the moment I can't afford 3 Genlockable cameras and I think a HDMI switcher will introduce even more latency...

Re: ATEM TV studio HD Latency

PostPosted: Wed Sep 05, 2018 9:05 am
by Xtreemtec
From the FAQ>> Here is also a nice topic about Latency.. Again boils down to external hardware that is causing the delay.. ;)

Re: ATEM TV studio HD Latency

PostPosted: Thu Sep 06, 2018 8:42 am
by stevemaster85
Just tested my setup and it seems it have 5 frames of latency, definitely not bad, if the ATEM will introduce just one more as you said its totally ok.

Now im going to read the topic you linked

Thanks for the support

Re: ATEM TV studio HD Latency

PostPosted: Thu Sep 06, 2018 4:44 pm
by Denny Smith
You could start adding csmeras, by using one or two BM Micro Studio csmeras for fixed, locked off shots to mix into the ATEM. They are very cost effective, around $1200 each, and can be genlocked down the road, if you need to.