[ This article was first published in the January, 2009, issue of
Larry’s Final Cut Pro Newsletter. Click here to subscribe. ]
Jonny Elwyn writes:
Thanks for the pleasant surprise of finding my last email in there! I am about to start on a DigiBeta project. Usually my workflow would be:
Digibeta J-30 deck > Firewire > DV > edit > DV master and DVD
However, after a lot of searching on the Internet, and with the aim of maintaining the highest quality, I’m trying to work out if:
a) its better to go SDI rather than FireWire (in general)
b) I should be capturing to ProRes 422 (rather than DV) – this would be a higher quality and help with roundtrip to color?
c) if i do capture to ProRes 422 will i need to go SDI or can i still do it over FireWire? (having read lots on ways of taking HDV to pro res over FireWire)
On this project i will be mastering to Digibeta. What would be the best modern (now we have prores) digibeta workflow?
Larry replies: The native format for DigiBeta video in Final Cut Pro is Uncompressed 10-bit. Using this codec means that there is no loss in image quality from the deck, as there is if you convert from DigiBeta to DV for transfer via FireWire
The only downside to Uncompressed 10-bit is that it requires a data rate of about 27 MB/second and takes about 99 GB to store an hour of media. The requires some fairly fast and large hard disks. Still, this is your best choice for quality.
An excellent second choice is ProRes 422 HQ. When used for SD material, it has a data rate of about 8.1 MB/second, and takes only 29 GB to store an hour of material.
while there is some potential loss in image quality compared to uncompressed 10-bit, it is still far better to use ProRes 422 HQ than DV.
If you have a lot of material, I’d suggest using ProRes. If not, I’d suggest Uncompressed 10-bit.
In either case, it is absolutely better to bring in your images via SDI than FireWire. However, SDI will require a capture card from AJA, Blackmagic Design, or Matrox.
UPDATE – Jan. 7, 2009
Matt Davis, from the UK, writes:
Following up on the DigiBeta workflow question, I used to use SDI in to the AJA IO, and – so I could edit with a laptop and external FW800 drive – used the DV50 codec. This had the benefit of 4:2:2 but only sacrificed the 10 bit to 8 bit. 10 bit was only sometimes necessary for chromakey and motion graphics.
Strictly speaking, DV was 5:1 compression, Digibeta 2:1 compression and DV50 2.5:1. But it did mean I could cut DigiBeta at near-as-dammit DigiBeta quality on a laptop in the field, and that counted for a lot.
Larry replies: Matt, thanks for the update.
