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Salvador Garza January 6th, 2009 12:28 PM

Mac/FCP workflow preserving 0-255 range
 
Hi guys!

I'm completely lost on the topic of preserving the 0-255 range when transcoding to an intermediate codec that's more appropriate for editing in FCP.

I remember someone suggesting using the Picture Style Editor in order to shoot in a low contrast setting.

I've already shot a couple of minutes worth of footage for a corporate video. I dialed down the contrast when shooting, but still getting crushed blacks.

Has anyone found any other viable solutions?

Thank you!

Evan Donn January 6th, 2009 01:29 PM

Do your edit in final cut pro with the native files, then send your sequence to Color when you are done. In Color use the primary in's luma curve to lift the blacks & drop the whites until you don't see any more detail appear between 0 & 100 on the scopes. Do additional color correction as desired, then render to ProRes, making sure your render preferences have the "Internal Pixel Format" set to "Floating Point" and codec to "ProRes HQ" to minimize banding.

Salvador Garza January 6th, 2009 01:39 PM

Thanks Evan!

But editing with the native files in FCP is very slow. Is Color actually recovering or seeing detail past 16-235? Or is it just applying a curve within that range and making things appear lighter/darker?

It seems like the same effect can be achieved within FCP on a ProRes timeline applying a high precision color correction plugin such as Colorista. But then FCP is only working within the 16-235 range.

Evan Donn January 6th, 2009 02:12 PM

You can clearly see detail being pulled back in from outside the range, both on the scopes and in the video itself, so I'm assuming it's working with the full range. The results are significantly better than what you can do with FCP's own color corrector; I haven't tried colorista in FCP.

Salvador Garza January 6th, 2009 02:19 PM

3 Attachment(s)
Here's an interesting find:

Before I was even aware of the color space issue with the 5DMarkII, I started using compressor to batch convert my original movie files to Apple's Intermediate Codec, in order to optimize my editing workflow.

I've attached three screen captures. Two of them correspond to the Levels effect in AE CS3. The one with the gaps is from a native 5DMkII clip. The other is the same clip converted to AIC using the Compressor Preset (AIC HD 1080p) shown in the third and last capture.
* I disabled color management within CS3.

Apparently the converted (AIC) clip has more shadow information and no gaps. What do you guys think?

Evan Donn January 6th, 2009 02:32 PM

looks like compressor is handling the conversion properly, I'm going to try the same thing to prores and compare the results.

Mark Palmer January 6th, 2009 02:54 PM

Color really helps to bring back the details, but is there any need for the ProRes conversion other than making the footage easier to use when it's put back in FCP?

If there is need, is there any compression loss?

Evan Donn January 6th, 2009 04:03 PM

1 Attachment(s)
Hmm, I don't think this is really working. I just ran the same clip through compressor to AIC and ProRes (using apple's presets), then brought it into Color and compared both with the original. The AIC clip appears to have been clipped hard at 16-235 then stretched back out to the full 0-255 range - detail is clearly lost in the shadows and highlights, and the contrast appears higher than the other two. The ProRes version appears to have been clipped at 16-235 but not stretched back - so lower apparent contrast but the end result is the same with detail lost at both ends.

The image below is the original on the left, AIC in the middle, and ProRes on the right. I've deliberately compressed the luminance on all three to make the clipping more visible - notice the posterization on the hair and missing detail along the window frame in the background.

Salvador Garza January 6th, 2009 04:09 PM

Did you apply the luma curve to the original clip?

Evan Donn January 6th, 2009 05:25 PM

yes, that's why you can see the detail in the hair & window in the first image - it's the original clip with compressed luma showing the detail that can be recovered using Color. Unfortunately it's not a great example (not a lot of detail to recover) but it was the first clip I found.

Salvador Garza January 6th, 2009 05:45 PM

Just fooled around with Color, and you're absolutely right, it recovers quite a bit of information on both sides. I've tested Compressore, Episode, Mpeg Streamclip and no luck in any batch conversion workflow that doesn't clip.


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