theoretical DVCAM question

[Jeremy Garchow]

You forgot option #3. Put the HD material in an HD timeline and let the Kona do the real time down-convert.

Jeremy

[Bob Roberts]

Interesting point. However, my concern has more to do with the output mechanism rather than the down-convert.

Is it better to go analog component>>DVCAM or firewire>>DV25?

[Jeremy Garchow]

It’s better to do the down convert in hardware and go out component.

Jeremy

[Walter Biscardi]

All of your P2 material will be DVCPro HD. Create a DVCPro HD timeline to match your DVCPro HD material.

Then set your Kona to do the downconvert in realtime.

Output to your DVCAM deck via Component either in letterbox or anamorphic or center-cut, whichever option you prefer.

hardware downconversion via Kona is broadcast quality and realtime.

Downconversion using FCP is not as clean as using the Kona hardware.

Walter Biscardi, Jr.
Biscardi Creative Media
HD and SD Production for Broadcast and Independent Productions.

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[Bob Roberts]

once again, THE COW ROCKS!!! thanks guys.

[Bret Williams]

So you’re going to go from digital DVCProHD, to Analog component SD, to DV25 and that is better than digital DVCProHD to digital DV25? I’ve done the latter many times with a standard firewire system, and the output was flawless. I don’t see how adding analog noise to the mix can be a good idea. I trust these guys, but I’d verify the results with a simple test.

[Jeremy Garchow]

[Bret Williams] “I don’t see how adding analog noise to the mix can be a good idea.”

By going through Quicktime (ie FCP) you are adding ‘digital noise’ (ie compression, 4:2:2 to 4:1:1, progressive to interlace, HD to SD, DVCPro HD to DV). The hardware conversion of the AJA card is done digitally, then output analog through hardware, then compressed in hardware (the deck) down to dv. Hardware conversions are USUALLY much better than software conversions. There are exceptions, but it’s usually the case. That’s not to say that Quicktime can’t or won’t do a good job, but using the Kona card, this process is literally a click of a button, no more renders, no reformatting, nothing. SInce he has the Kona card, I would say do this process in hardware, if one doesn’t have access to a card, then software is the way to go.

Does that make sense to you or am I yappin’ my mouth again?

Jeremy

[Bret Williams]

I would agree if it wasn’t being converted to analog which introduces noise. The minute it becomes analog component SD is the minute it becomes the equivalent of betacam SP, which has more signal noise and less luminance latitude than DVCam. Component has better color rendition than DV, but it’s about to lose that when it gets compressed to DV in the deck. The analog component should add setup. Then, on the conversion to DV it’s going to get stretched back to 0ire. That can’t be good for the luma.

Can the Kona convert DVCProHD to DV25 (and output fw or sdi) on the fly? A digital to digital hardware conversion would obviously be the best bet.

I don’t have the Kona here to test, and I’m sure it looks great to do it either way. I’m just saying I’d run a quick test to make sure the analog process doesn’t soften the image. Just the quality of the cables could be a factor.

[Jeremy Garchow]

[Bret Williams] “A digital to digital hardware conversion would obviously be the best bet. “

Obviously if the deck had SDI, this conversation would be moot. But it doesn’t so it’s not.

As far as adding setup, setup is going to be added anyway at some point, so what’s the difference where in the chain it gets added?

[Bret Williams] “Can the Kona convert DVCProHD to DV25 (and output fw or sdi) on the fly?”

No, it outputs uncompressed SD (or HD) and depending on the bit depth of your timeline, it outputs either 8 or 10 bit.

FCS2 can output anything via the FW400 port (a real time downconvert to dv of sorts) but it is not pretty when coming from higher quality codecs and bit depths.

Jeremy