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Live switch between two HVX 200s


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#1 Kalin Ivanov

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Posted 03 January 2008 - 09:04 PM

Could you, please, advise me on Video switcher that I could use on-location for a two HVX 200 live switch?
Thank you in advance and Happy New Year!!
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#2 Michael Nash

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Posted 04 January 2008 - 01:12 AM

Without being able to gen-lock the cameras it's going to be pretty difficult...
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#3 Mitch Gross

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Posted 04 January 2008 - 10:31 AM

We have the Panasonic AV-HS300, which is designed exactly for this task when used with the optional component video board (included in ours). It can live switch up to five of these cameras an gen-locks the signal. It is available for rental.
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#4 Walter Graff

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Posted 04 January 2008 - 11:32 AM

There are a number of devices and switchers on the market that can take everything from composite (have an onboard sync generator so no external genlock necessary)(Panasonic and New Tek, etc) to firewire enabled switchers (Comprehensive,etc). All depends on how much you want to spend and how sophisticated you want ot be.
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#5 Michael Nash

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Posted 04 January 2008 - 11:40 AM

There are a number of devices and switchers on the market that can take everything from composite (have an onboard sync generator so no external genlock necessary)(Panasonic and New Tek, etc) to firewire enabled switchers (Comprehensive,etc). All depends on how much you want to spend and how sophisticated you want ot be.


Good to know...
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#6 John Sprung

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Posted 04 January 2008 - 02:04 PM

Without being able to gen-lock the cameras it's going to be pretty difficult...

That was the way it had to be done back in the days of analog video. The same basic idea should work with digital, syncing the readout of the chips. But it would also be possible to just leave the cameras alone, and fix everything in the switcher. What you'd have to do is dump each input into its own rotating loop of buffers, and just read out the buffers at whatever time you need them. The downside is that you'd have a frame or two of delay, and you'd need to delay the audios as well to keep sync. The upside is that it's self contained in the switcher.

I'm not sure how it's really done, so I'll ask some guys who do live football games.




-- J.S.
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#7 John Sprung

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Posted 04 January 2008 - 02:56 PM

I'm not sure how it's really done, so I'll ask some guys who do live football games.


Here's the answer from one of the top guys in live TV:

> We still genlock. If you do frame synchronization later, you add delay. Sometimes, for a particular camera, we might use a frame sync, but the rule is genlock.
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#8 Walter Graff

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Posted 04 January 2008 - 02:57 PM

There is no difference when it comes to today's professional digital cameras compared to analogs past in terms of genlock and syncing such things as timecode. Want to sync two HDCAMs, they must be genlocked. Want to sync two JVC HD250's, they must be genlocked. As long as two devices have two seperate time bases, they need genlock. Some of today's newer prosumer cameras have the ability at being hooked up and synced via firewire though. That uses a different process to talk to each other. And prosumer cameras that do not have genlock where you want to shoot live now have the ability to be mixed easily. There are at least twenty different switchers on the market that take up to 6 firewire cameras in and do the same mixing with effects and chromakey that regular mixers do all with one firewire 400 cable to camera. A number of rental houses now have them too.
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#9 John Sprung

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Posted 04 January 2008 - 04:53 PM

Further explanation:

They genlock every camera they can. Usually that's quite easy, because they only need to get genlock to the CCU's which are only a few feet from the switcher, on the same truck. There are sometimes "wild" cameras in hockey nets or basketball backstops that can't be genlocked, so they have to run those through a frame sync box, and the box is then genlocked to everything downstream. The box costs about $15K, and a frame or two of delay, so they only go that route when they absolutely have to. Sharing signals between multiple trucks is sometimes done by going through a frame sync box.




-- J.S.
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