Blackmagic Multibridge Pro

[Martin Kornfeld]

Hello,
I'm shooting/editing a 10 minute promo video for local JC. Will be using my Canon XH-A1 in HDV mode. Using the school's MacPro FCP 6 syystem with Blackmagic Multibridge Pro. End result will be distributed on DVD in SD or HD as called for.
My assumption is that there's no need or ability to capture HDV through the Multibridge Pro from the XHA1 as feeder deck.
Question 1: Is that true?
Question 2: In what capacity does the Multibridge Pro come into play if any?
Question 3: Edit in HDV timeline? There will be moderate amount of effects especially for the open.

Thanks,
Marty

[Chuck Spaulding]

There's no real benefit to the Multibridge with HDV, other than providing the ability to view an HD time line on an external monitor.

A new feature in FCP 6.0.3 is that you can now capture HDV via firewre directly to ProRes in real time. If you have enough storage I would recommend that workflow rather than editing HDV natively.

[Martin Kornfeld]

I just found out I'll have a Canon HV20 for capturing. Would there be an advantage to using that with HDMI through the BM to ProRes now that it's possible to go through firewire?
Also I may only have an SD monitor to use. Will the BM downconvert in real time off the timeline?

[Kaku Ito]

Multibridge Pro does realtime downconversion for monitoring.
My opinion is that good SD monitor is useful even color correcting HD footage and monitoring interlaced footage.

Firewire connection will allow you controlling the cam via firewire, if you use HDMI to capture via Multibridge Pro, advantage would be that you can record as uncompressed HD, but you won't gain so much in quality since it is recorded as HDV.

One thing to consider with Prores is that the playback quality is influenced by the performance of the computer.
I've seen some 1080i clips not playing right (fast panned footage) on the fastest Mac Pro.
It seems to record and hold the data right, but the playback is certainly influenced because if we transcode the same clip that has playback issue to uncompressed HD, it plays fine.

[Martin Kornfeld]

Originally Posted by Kaku Ito

Firewire connection will allow you controlling the cam via firewire, if you use HDMI to capture via Multibridge Pro, advantage would be that you can record as uncompressed HD, but you won't gain so much in quality since it is recorded as HDV.

So there is no advantage to using BM for capture? Also if shooting at 30p will there be any technical issues to look out for?

Thanks all for replies so far.

[Chuck Spaulding]

There are several issues being mixed together here which you will have to decide for yourself which way you want to go. Unfortunately many of these discussions take on a life of their own and turn into a debate of how best to handle HDV.

There is no time code or machine control in HDMI, so if you don't need time code and use capture now HDMI does have an advantage, the signal that comes out of the HDMI spigot passes through the decks error correction providing a cleaner signal, this does not happen while capturing via firewire. Its a noticeable difference, if you go to this link at the bottom is an example of HDMI capture vs HDV:

http://www.convergent-design.com/CD_...DConnectMI.htm

[William Hohauser]

Originally Posted by Chuck Spaulding

There's no real benefit to the Multibridge with HDV, other than providing the ability to view an HD time line on an external monitor.

A new feature in FCP 6.0.3 is that you can now capture HDV via firewre directly to ProRes in real time. If you have enough storage I would recommend that workflow rather than editing HDV natively.

What are the hardware requirements to capture HDV to ProRes in real-time? I tried to find it on Apple's site but had little luck.

[Chuck Spaulding]

Originally Posted by William Hohauser

What are the hardware requirements to capture HDV to ProRes in real-time? I tried to find it on Apple's site but had little luck.

It was an odd thing, it just appeared in either the 6.0.2 or 6.0.3, I don't think there was ever any mention of it on the website.

I'm on a Mac Pro 2.66GHz, 5GB RAM and x1900.

I have not captured a lot of material yet [six hours or so] but it seems to work well.

[Martin Kornfeld]

No timecode with HDMI through BM. So FCP will generate internal time code? And my only reference to actual footage will be by tape number? I take it no audio either. Use analog audio out of camera thru BM?

Chuck Spaulding wrote:
"Its a noticeable difference, if you go to this link at the bottom is an example of HDMI capture vs HDV:"

http://www.convergent-design.com/CD_...DConnectMI.htm

Chuck, This example seems to be comparison between HDMI and anolog component rather than firewire. Am I right?
Would the difference not be that great then between firewire and HDMI?

Wow, so many variables these days - it seems a little crazy to this (somewhat) old timer.

[Kaku Ito]

I would say there aren't great differences in quality between HDMI and firewire capture in this case.

HDV to prores is nice because it eliminates longGOP editing issue and after your editing, porting over to Color for color correction would be smooth.

I would actually take that route since it is available now.

[Chuck Spaulding]

Originally Posted by Martin Kornfeld

Chuck Spaulding wrote:
"Its a noticeable difference, if you go to this link at the bottom is an example of HDMI capture vs HDV:"

Wow, so many variables these days - it seems a little crazy to this (somewhat) old timer.

Actually what they are demonstrating is the conversion from HDMI to HD-SDI. Part of the reason there's a noticeable difference is when outputting HDMI the deck uses built in error correction to clean up the signal which it doesn't do for an analog output and because of the bandwidth constraints it can't do for output via fire wire. By the way, HDMI output also includes the audio.

But what you don't get is time code or machine control which means that if you want to go back to the original tapes to re-conform a project, you can't. [not easily anyway].

The simplest thing to do is to capture HDV via firewire to ProRes. The downside to this is the amount of data generated, approximately five times as much as HDV. FW800 drives should handle a couple of streams comfortably but you will have to manage your data more carefully.

I guess this has been a rather long thread to say no there's really no benifit to using the Blackmagic Multibridge Pro.

[William Hohauser]

Originally Posted by Chuck Spaulding

I guess this has been a rather long thread to say no there's really no benifit to using the Blackmagic Multibridge Pro.

In this particular use; HDV to SD DVD. But if you have the equipment, no reason not to use it.

[Martin Kornfeld]

Thanks all for your input and advice.