Thu May 31, 2018 12:21 am
Hello everyone. I just wanted to offer some observations about the Television Studio 4K Pro. Switchers kind of tend to be multi dimensional as in inputs, outputs, features, rates and resolutions. So saying the most powerful may have different meanings to everyone. In this case, the internal processing is very powerful compared to all other ATEMs given the magnitude of scalers, frame synchronizers, and Fairlight audio processing up to 12G signals. You will find the SDI inputs more forgiving with that pesky 60Hz frame rate as well. I would say the Television Studio Brand has progressed over the 8 years of development with Blackmagic. While we don't talk about the future, it is easy to see where things are going for other models.
One thing that was very important to me came up in this thread. Latency or delay through the switcher is most important to just about everyone working in a live environment. With the addition of the much asked for scaling as well as the existing frame synchronizers, one would expect there to be an impact to latency. I wanted to test first hand how this was working so we can speak correctly about this functionality. While there is no user selection to enable or disable scaling or frame synchronizing, the ATEM TVS 4K Pro automatically uses these functions when they are needed and does not use them when not needed. So while I can talk quit a bit about the subject, the simple description is this:
If you feed any input the same resolution and frame rate as the ATEM, the delay will be from a few lines to a frame. If the source is genlocked the same as the ATEM, the latency will be a few lines. If this sounds like what we state for all ATEMs, that is correct. For the TVS 4K Pro, if you feed a different resolution or frame rate on an input, then the ATEM automatically will scale that resolution and rate, plus frame sync as necessary to match the ATEM. The scaling process will naturally add a frame or two to the process based on what rate and resolution is being scaled. And as always, if the DVE is used, the image in the DVE will be one frame later than the rest.
So, we feel there is no latency difference for this switcher than the others unless you use the popular new scaling capability. At the risk of talking too much, I would like to offer an important tip for those ATEM users with Blackmagic Studio type cameras. All of our Studio type cameras have the capability of genlocking both to external sync or return SDI video from the ATEM (or any switcher). As you would normally feed the ATEM Program or Auxiliary output back to the camera, I recommend setting the camera reference to "Program". This will match the timing to the ATEM which is what you want specifically. And this is the most important part. The next setting in the camera menu is called "Reference Line Timing". Set this to "-5" or a lower negative value. The purpose of this is to "advance" the camera vertical timing by a few lines so it reaches the ATEM input "ahead" of the switcher vertical. Doing this will insure the frame synchronizer will not delay an additional frame through the ATEM. I have verified this with all ATEM switcher models. This adjustment is in all Blackmagic studio type cameras which include the Television Studio Cameras, Micro Studio Camera, URSA Mini, URSA Mini Pro, and URSA Broadcast.
Thank you for taking the time to read this. I trust this will be helpful in your setups.
Regards, Gary
Gary Adams
Blackmagic Design