FireWire vs SDI Capture

[Daniel Andreas]

We shot a project on DVC Pro 50, on the SDX 900 in 24p. We captured on a DVC Pro 50 deck into Final Cut Pro using FireWire. We have mixed the film, and now it's time for hidef upres and color correction at a local post house. Is there any benefit of going back to the camera originals, and reassembling the master via SDI? Is there any quality improvement? Reassembling could be time intensive and costly due to many split screens, so we are looking to avoid it, and stay with the FireWire transfer we originally did, as long as there's not a major quality compromise.

[Dan Goulder]

The master tape you assembled should be fine. Let the post house exercise the option of SDI input to an uncompressed timeline for color correction.

[Michael Collier]

As long as under capture settings you had DVCPRO50 selected. I am unfamiliar with final cut, but if your software is capturing DV25 or DVCPRO, then it might be dropping about 1/2 the info DVCPRO50 stores. otherwise it should be lossless (well at least you dont loose anything after the SDX compressed it in the first place.)

[George Lekovic]

Hi,

 

whatever you captured via FireWire is a down-conversion. That means it is not the full quality material, and it does not contain all the info your master does. You do want to go back to camera originals and re-capture using a high-quality capturing card, and if you don't - yes - you will be amking a major quality compromise.

 

A lot of decks that play DVCPro50 offer FireWire output. It is not a full quality signal, but rather a down-conversion.

 

Hope this helps.

[Matt Lazzarini]

Hi,

 

whatever you captured via FireWire is a down-conversion. That means it is not the full quality material, and it does not contain all the info your master does. You do want to go back to camera originals and re-capture using a high-quality capturing card, and if you don't - yes - you will be amking a major quality compromise.

 

A lot of decks that play DVCPro50 offer FireWire output. It is not a full quality signal, but rather a down-conversion.

 

Hope this helps.

 

Interesting. I was looking at this very same question the past few days, and from what I gathered through online research, capturing through firewire is virtually identical to sdi capture. Firewire should just be an exact transfer of bits from source to computer.

 

For example, these links:

Capturing DVC Pro50, FireWire vs SDI

 

SDI vs Firewire at dvcreators

 

HD for Indies

[Dan Goulder]

Hi,

 

whatever you captured via FireWire is a down-conversion. That means it is not the full quality material, and it does not contain all the info your master does. You do want to go back to camera originals and re-capture using a high-quality capturing card, and if you don't - yes - you will be amking a major quality compromise.

 

A lot of decks that play DVCPro50 offer FireWire output. It is not a full quality signal, but rather a down-conversion.

 

Hope this helps.

If you're using editing software such as FCP, which offers native editing of DVCPro 50, there will be absolutely no truncation of digital information through firewire. Your assemble edits will be lossless, done without any additional compression. You're dealing with a direct digital clone, with no information added or subtracted. Using SDI will enable the post facility to input the tape to an uncompressed timeline, which can allow for additional latitude in color correction. Leave that to them. Redoing the work you've already done would be a questionable use of time and expense.

[Keith Mottram]

Hi,

 

whatever you captured via FireWire is a down-conversion. That means it is not the full quality material, and it does not contain all the info your master does. You do want to go back to camera originals and re-capture using a high-quality capturing card, and if you don't - yes - you will be amking a major quality compromise.

 

A lot of decks that play DVCPro50 offer FireWire output. It is not a full quality signal, but rather a down-conversion.

 

Hope this helps.

 

This is wrong and misleading. It could in fact be argued that an SDI input would be a downconversion as you are shifting the data into a different form. Secondly Firewire (or IEEE) is a way of transporting data so talking of full quality signal is totally irrelevent.

 

Keith