10 bit or 8 bit? Is 10 worthwhile in Vegas?

newcancin wrote on 10/21/2005, 5:03 PM
Hi, first post here. I've been doing some searching and found some partial answers, but not enough so far. Sorry if these have been asked before. There must be some people in a similar situation or have been in a similar situation.

Basically I have the raw film footage for a short film about to be telecined and transfered direct to harddisc in "uncompressed" standard def 4:2:2. The whole idea is to bypass DV compression altogether as the final format for film festival play (hopefully) is digibeta arrived at with the most economical workflow I could come up with while keeping the beauty of film. Now I have a choice to make about whether I get my raw footage done at the posthouse at 10 bit or 8 bit. After some searching on here, I find that Sony Vegas 6 only outputs to 8 bit, and I haven't been able to find out if:

a) There is any advantage at all to getting it done at 10 bit? Or is it just going to slow things down?

b) Does Vegas 6 resample or does it select 8 bit information from a 10 bit source? And what does that do to quality? Anything?

c) There was mention of a Black Magic codec for sdi that I'll have to get with the 10 bit, anyway (maybe with the 8 bit, too?). The transfered film will be on a regular harddrive with usb. Likely some people on here know about this codec and can verify it will work fine with Vegas 6?

d) Finally, I would assume I'm a lot better off sticking with AVI over mov with Vegas as my file choice from the posthouse, am I right?

Thanks for any help with this.

Comments

farss wrote on 10/21/2005, 5:16 PM
a) and b) Damn good question and I wish I knew the answer.
c) Yes it works with Vegas.
d) Used both, both work.

Bear in mind if your final output is DigiBetacam then as far as I know it's only 8 bit 4:2:2. However the audio is 24 bit which is rather nice and upto 8 channels as well. Sadly Vegas don't do that but you might find a post house that can somehow get that from your files onto DB.

Bob.
rmack350 wrote on 10/21/2005, 5:40 PM
Is there an advantage to going 10bit over 8bit? I'd think that it depends on your chain and the final output. If it were finally 10bit or if the plan were to go back to film then maybe you'd want to try to stay up in 10bit.

I think Vegas will sample 8bits out of the 10. There was a cineform related post here today that, if you follow all the links, gave a few hints on this.

You may find that you need a pretty buff system to do this work.

My employers are starting to show their film "Ballets Russes". They faced a lot of similar choices. Although they originated in DV25, they edited in 422 on a media100 and did their compositing in an 844 system at 10bit color depth. It looks quite good!

If you google it you might find an interview where Dan Geller talks tech about it.

Rob Mack
newcancin wrote on 10/21/2005, 6:08 PM
Ah, I see farss had asked a similar question or two in the cineform thread. Thanks. Some hints there. This must be a general question that's been asked before a few times if that's twice in one day? I'll try and find that interview and see if it gives me any more answers. Thanks.
Coursedesign wrote on 10/21/2005, 6:35 PM
Vegas can straight-cut 10-bit and keep it 10-bit, but if you use any transitions or effects, it can only output the result as 8-bit.

Choices are to do all effects etc. in Combustion or After Effects, or get Adobe Premiere Pro (which handles 10-bit). Note that AE can only do 8-bit or 16-bit, while Combustion can also do 10-bit which saves disk space.

The 10-bit Blackmagic codec works beautifully in Vegas, I have been using it for more than a year. I think you can download it for free without buying the card. Note that installing QT7 will screw up BM for the moment.

10-bit gives you more freedom in post processing (because of wider latitude and more), but it may or may not make a large enough difference for your particular footage. Was it shot on 8mm, 16mm, or 35mm?

Digibeta is always 10-bit, the confusion is only because some 8-bit NLEs output DB with the last 2 bits set to zero.

farss wrote on 10/21/2005, 7:33 PM
"Digibeta is always 10-bit, the confusion is only because some 8-bit NLEs output DB with the last 2 bits set to zero."

Well this is what I had thought but after some extensive tests down here the conclusion was that DB cameras only write 8 bit data to tape. Given that those who ran those tests have a large fleet of DB cameras and an equally large group of engineers they could well be correct. What clouds the issue is that what comes down the SDI port isn't a bit copy of what's on the tape, you could well be getting 10 bit data that's interpolated from 8 bits. I was also told that when they fronted Sony with this information it was not disputed. But if anyone knows of any authorative tests that confirms what's actually written to tape by the cameras then I'm all ears.
What also clouds the issue is that the BMD cards when capturing from component can write 10 bit data, I think the SP decks with SDI ports also send true 10 bit data.
Bob.
newcancin wrote on 10/21/2005, 7:52 PM
This tells me a lot, thanks!

It was shot in 8mm plus-x black and white, but with care and prime lenses. I'm doing it uncompressed to digibeta because I've seen some pretty nice examples at film festivals with that formula. DV's not enough from what I've seen or tried out and adds too much "video information" to the shadows, while HD would be great but overkill I think for this application and an unneeded expense. So it's now down to the 8 or 10 bit quesion.

There's only a little in the way of transitions and effects, but there are some that are unavoidable and I can't see spending three thousand or whatever Combustion costs as that will basically double the cost of my little short. :) And I'd like the freedom to add or subtract some which may come up as I'm editing which makes paying studio time somewhere or hiring somebody kind of inconvenient and it still will cost a significant amount.

Seems like 8 bit is enough. Especially if 8 bit will get everything there is to get out of it anyway. It sounds like it will.
rmack350 wrote on 10/21/2005, 8:19 PM
At this point I don't know if an interview about the technology was even published but the search terms would be ballets russes, dan geller, media100, and 844.

At times the 844 system was a dream, at other times a nightmare. There's some chance that the interview was never published.

In the end this doc was uprezed to HD and I believe there have been film prints struck. I saw an HD projection at Sundance and it looked great!

Rob Mack
Coursedesign wrote on 10/21/2005, 9:20 PM
Black and white benefits even more than color from 10-bit, sorry.

Of course, if you are after a gritty look, there is no need to worry about this.

A good compromise otherwise could be to ingest in 10-bit and then "color correct" to get the best 8 bits out of each scene, then edit in Vegas as usual.

The lab may even be able to pick the best 8-bit settings for you on a scene-by-scene basis, and it shouldn't be expensive unless you have a large number of very different scenes.

Combustion used to be $5K, now it's just under $1K list, the same price as After Effects Pro (the basic version of After Effects is only 8-bit). Worse is that both of these apps take a good while to learn, so don't let the technology rob you of your creative energy.

DigiBeta is recorded in 10-bit, but can output 8-bit for the deprived (and 10-bit for the depraved :O). See for example SMPTE BB. As you can see, even many top pros are confused about this, but it is a 10-bit 4:2:2 recording format.

newcancin wrote on 10/22/2005, 6:26 AM
"A good compromise otherwise could be to ingest in 10-bit and then "color correct" to get the best 8 bits out of each scene, then edit in Vegas as usual."

Well that's exactly what I think I'll try and do then!

Thanks everybody.
farss wrote on 10/22/2005, 7:55 AM
Actually the best results will come from getting a well timed transfer off the film, even at 10bit you're lossing a lot of what the film has stored on it. The solution is controlling the amount of light going through the film during the transfer. You'd probably get more for your dollar spending it on this pahse of the process than anywhere else.
Of course though you have to make the decisions early in in the process unless you want to ge back and do another timed transfer but that could get very messy, I think.