Uncompressed 10-Bit Gamma Shift

[Neil Sadwelkar]

We output from a DaVinci Resolve as Uncompressed Quicktime. These are large movies and not like the Uncompressed 10-bit movies that FCP and Quicktime.

In Quicktime player, the movie properties look like this…
screenshot2009-11-05at7.58.37pm.png

By default, this is a ‘log’ quicktime which needs to be linearized. We usually do it in Shake with the Truelight node set for the correct film stock.

Or else it can also be linearized by the post facility. In that case the colours will be correct. We make these kind of quicktimes and then convert them to ProRes in an FCP system. We’ve seen no significant shifts in gamma or colour.

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Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India

[Adam White]

Hi Neil, thanks for your reply.

I’ll ask the post-production house about this, but if they can’t linearize the uncompressed QT for me, can I do this myself? I’m assuming this is an essential step, and am I correcting in thinking that if this isn’t done then I won’t be able to convert the QT into a functioning ProRes file?

I have Final Cut Studio 3, and I know Shake is included though I’ve never used it before. We shot on HDV1080i60. What settings do I need to apply to the file in Shake, and are there any tutorials online? I’ve run a search but couldn’t find anything though this is all new to me so in reality I’m not really sure what I’m looking for.

I would guess that we’ll probably have to linearize the file ourselves, so would greatly appreciate any advice.

Thanks,
Adam

[Rafael Amador]

Here you have something to start with logarithmic files:

https://magazine.creativecow.net/article/cineon-files-what-they-are-and-how-to-work-with-them

In the Shake’s manual there is interesting info too.
BTW, Shake doesn’t comes in FCS and I don’t think Apple still selling it.

rafael

http://www.nagavideo.com

[Neil Sadwelkar]

Shake is not part of FCS and if you don’t have it you can’t buy it any more.

The Resolve facility will need to linearize for you with their LUT so they can confirm it with their calibrated monitors.

If they cannot/do not, and you don’t have shake, I will need to check if Color can do the log-lin conversion on a Quicktime that’s in log space. Incidentally, color can definitely do log-lin and rather good conversion, but on DPX or Cineon files.

Another utility that does a good log-lin and even provides controls for tweaking this, is Pomfort Cinemator.

The conversion from Resolve uncompressed Quicktime to Apple ProRes will be handled by compressor, or Color.

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Neil Sadwelkar
neilsadwelkar.blogspot.com
twitter: fcpguru
FCP Editor, Edit systems consultant
Mumbai India

[Beverly Maguire]

I get uncompressed Blackmagic 10 Bit, 1920 x 1080, Quicktimes from My Compositors. When I am finished with the Edit I need to Deliver DPX’s to the graders.
I exported a Quicktime AJA 10-bit RGB Codec, 1920 x 1080, and Converted it to DPX using the AJA to DPX converter.

But when I check the DXP the Gamma has shifted.

It wont convert Uncompressed 10 Bit Quicktimes, it says it has to be RGB so Im thinking its the AJA that’s changing the colour.

Please Help How can I export an Uncompressed Quick time (So to have no colour change) To DPX’s for the Grading process.

Bev