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View Full Version : film scanned to proRES...Help



lou4uandme
October 23rd, 2010, 12:07 PM
HI all,

Ok, I have a 5 minute short that was filmed on 35 mil and was transfered (scanned) to a quicktime ProRES 4.2.2
It was filmed & scanned in Prague/FAMU, from a film student. They gave him 2 choices for the transfer to be in, and he picked Quicktime.(wrong choice I bet)
He gave me the edited version that he said is an exact duplicate in QT properties.

Frame Size = 1920 x 1080
Compressor = Apple ProRes 422 (HQ)
Quality = Most (5.00)

From what I understand, film scans are 10bit dpx files. So I don't know if I should treat this as a "Video" 8 bit or a "Film " 10 bit log?

I am doing color grading on it and from what I hear, 10 bit would give better headroom and better results.
Did we loose any chance to using it as a 10 bit by using a Quicktime?
Is there any way to convert it to 10 bit?
I am so confused....

Thanks,
lou

forkazoo
October 23rd, 2010, 12:35 PM
The ProRes "HQ" codec actually is 10 bit YUV, so depending on what exactly happened to the data between the scanner and the QuickTime files, you should have 10 bit images in there.

That said, whether it is linear/video/log - there's no way to tell from what you have said. It's also a completely separate issue from how many bits you have. It's perfectly possible for an image to be 10 bit linear, or 8 bit log, etc. (Though, 8 bit log would certainly be uncommon.) You'll have to talk to whoever did the transfer to find out what exactly was done with it as far as color space handling. Does it look like log? If it looks fairly normal, my first guess would be that your ProRes files are going to be in rec.709 color space, but that's purely speculation. (It's sort of the "standard" HDTV color space. If somebody was giving your HD res ProRes QuickTimes, I'd guess they would assume that's what you wanted.)

As far as converting 8 bit to 10 bit, of course it's possible to convert between the various formats. You just store each pixel with an extra two bits. It doesn't add any real data, though. It's like asking, can I convert the 5 digit number "345.73" into a 7 digit number. Of course you can. It's "345.7300"

What are you using to do your grading? Perhaps somebody will have used the same system, and they can suggest some specific settings for making sure that it uses the highest quality calculations that it can do.


Maybe this helps a little bit. If not, keep asking questions. :)

lou4uandme
October 23rd, 2010, 02:20 PM
Hi again,
Thanks so much for the reply

Well, when I import it, it looks fine, no weird gamma shifts.
Is there a way to find out for sure what it is for sure?

Also, I have access to Scratch & Nucoda at work, and I tried it in Scratch.
I am very confused, when I look at the properties, it said RGB-10 LIN

But when I look at the properties in Premiere, I get this:
Type: QuickTime Movie
File Size: 5.8 GB
Image Size: 1920 x 1080
Pixel Depth: 24
Frame Rate: 23.976

So my next question is this:
If it turns out to be a 10 bit QT Linear file, Will I be able to push the colors more than an 8 bit or is it the same sH_t?

forkazoo
October 23rd, 2010, 04:16 PM
The only way to find out what it is for sure is to find out more about exactly how it was made.

If the scan was done properly, then yes, you should be able to push harder on the 10 bit file than you would be able to if it was 8 bits. It would be even better if you had 444 data instead of 422, but it will probably be fine. What you have is probably not exactly linear, but it's not log, so you can pretend it is linear.

If it had been me, I would have requested something else from the people scanning it that isn't lossy compressed, but ProRes is pretty well respected so you shouldn't really be able to notice much of a difference.

beaker
October 25th, 2010, 11:53 PM
film scanners don't work in linear. It is most likely rec709 or some type of gamma space. Best to ask the lab which did the transfer.

crashd
October 28th, 2010, 07:14 AM
As Beaker said, if it wasn't transferred log > ProRes 10bit (if it was 'log' it'd look washed out and flat) it's more than likely video/rec709. If you had shot some test charts you may be able to tell if it was transferred proper 709 or linear but it won't make _too_ much difference if you have a decent colourist.