Studio Varicam Shoot with a HD-SDI capture…advice please.

[Matthew Romanis]

We recently did a test for the same reason, and yes it works but you must use the 8bit capture setting, and only the HD-SDI on the side of the camera offered a usable signal.

[Matt Bishop]

Thanks for your input –

I have a couple of quick questions for you, if you don’t mind

How did you keying tests go, were you happy with the footage?

Did the HD-SDI signal have embedded t/c and audio?

So you went into your suite 8bit uncompressed 720p 60p, and it maintained a 24fps look?

Thanks so much for your time and good luck with your tests and shoot.

Cheers
Matt

[Matthew Romanis]

Hello fellow Matt,
I haven’t seem results from the test yet as the client took the drive away to their own facility, but I believe it is all well.
The HD-SDI signal does not embed TC, and I can’t answer about the audio from the camera as it was not in our test protocol. If you are using FCP for ingest you will need to disable the default 12 channel audio setting in capture as this results in renders. 4 channel seems to work OK.
In our case, because we use the Black magic card the codec for the 25/24 settings is looking for the 25/24 flagged frames in the 60fps stream. So yes, with the correct equipment and settings the footage will be 24fps. If you are using Black Magic HD the new drivers have dedicated Varicam setups, you would need the 720p@24fps 8 bit setting. It will pull out of the 60fps stream the 24 flagged frames for each second, thus giving you the 720p@24fps look you are after.
By the way are you using a true 24fps time line or an NTSC derived one at 23.97fps?

[Matthew Romanis]

Hello fellow Matt,
Just a correction to what I posted above. You can use the 10bit capture option as long as the HD-SDI PB/EE switch in the audio panel is set to provide the 10 bit stream from the camera head.

[Gary Adcock]

[Matt] “Has anyone had any experience capturing live on set via HD-SDI and if so how did they feel about the image quality and which codec did you use?”

I do this monthly, and I have done this in the 8bit, 10bit, DVCPROHD, and (down-converting to) DV25
compressions, The K2 can actively see the flagged frames and remove them.

[Matt] “”It is important to understand that only the camera section operates at variable frame rates. The VTR and the camera HD-SDI output operate at a constant 60-fps rate.”” This is correct, the camera ALWAYS plays 60 frames to the video stream.

There are issues with FCP capturing live on set – FCP does not record TC over SDI, and the “Capture Now process is very hardware intensive so be prepared.

Gary Adcock
Studio37
HD and Film Consultation
Chicago, IL USA

[Matt Bishop]

Hey Gary, and fellow Matthew, thanks for your help on this.

When you were working in studio did you record a tape back-up and if you did how did you sync the timcode? I was hoping there would be a way that I could take the T/C out of the camera and run it directly into my Decklink HD Pro card, is that possible?

I might be creating a arguement by asking this but did you find the difference in 8bit to 10bit from the Varicam enough to warrent the extra drive space and speed? I am using the footage for Chroma Keying purposes so I imagine that 10bit will be beneficial to me.

Thanks Again Guys

Matt

[Matthew Romanis]

Hello fellow Matt,
Re the 8-bit -10-bit argument, people will always say bigger is better, and most times they are right. In the automotive industry they say there is no substitute for cubic inches, mind you engineers with turbo chargers, multi valve heads, and variable compression have shown you can make a convincing argument against.
If anything there may be a little banding with 8-bit if the green is very flat, but that is the layer that will get replaced and the banding represents a very low threshold to most keyers. If you have the space go for 10 bit.
I remember seeing a rack mount device from Sony some years ago that translated the audio type TC signal VCR’s and Cameras produce into RS 422 data. Some one here may know what that device is called. Something like this would allow you to simply roll the camera and know that time-code is going to your NLE. I don’t know if there is a delay or not, and if there would be any loss of the flagged frame info, though with some recent tests I have done with a 1200a, I’m not sure if the card is actually looking for flagged frames or if it is working on a set algorithm that pulls out the order of frames to make the 24-fps capture. If it is the latter it would mean the card always has to start the process on the 0 frame of every second.
It’s very important you do some tests before shooting, the info that you read here on cow will get you off in the right direction.

[Walter Biscardi]

[Matt] “Did the HD-SDI signal have embedded t/c and audio?”

Yes, the HD-SDI signal carries audio, but no timecode. We recently shot an independent film and double rolled each take by sending the HD-SDI signal to a 1200A deck. Audio was brought down the HD-SDI signal as well.

No T/C though, that is sent down a separate path.

Walter Biscardi, Jr.
Creative Genius, Biscardi Creative Media
https://www.biscardicreative.com

Now in Production, “The Rough Cut,” https://www.theroughcutmovie.com

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[John Sharaf]

Walter,

Actually the TC is also embedded in the HD-SDI signal; on my 1200A when we backup record, we get HD video, audio and tc on the one piece of coax. Also my Leader LD5700 waveform is able to dis-embed the TC and display it (or clock time) in the top right corner of its display.

JS

[Walter Biscardi]

[john sharaf] “Actually the TC is also embedded in the HD-SDI signal; on my 1200A when we backup record, we get HD video, audio and tc on the one piece of coax.”

That’s interesting. We haven’t been able to see that here. We run a second cable down from the TC out. I’ll have to look into that and see why we’re not seeing the TC down the same line.

Walter Biscardi, Jr.
Creative Genius, Biscardi Creative Media
https://www.biscardicreative.com

Now in Production, “The Rough Cut,” https://www.theroughcutmovie.com

Now editing “Good Eats” in HD for the Food Network

“I reject your reality and substitute my own!” – Adam Savage, Mythbusters

G5 Dual 2.0, AJA Kona 2, Medea FCR2X