Legal Levels with a Scope and FSI

[Sascha Haber]

This option on render does the opposite you would think .
It scales the video form 64-940 to 0-1024 on output .
If you want it to stay legal, you need to render data level .
Makes sense ?
Yeah, to me too …
To check if you are safe, use a Lut with a nice soft knee or look at your scopes AFTER rendering.
So bring it back in and check .
All of this of course works for DPX only, if you render to MXF and stuff you also need to make sure tout clip attributes are set correctly..

A slice of color…

Resolve 9.01 OSX 10.8.2

Colorist / Aerial footage nerd
https://vimeo.com/saschahaber

[Stig Olsen]

William, what is your finishing tool?

[William Edwards]

They are outputting with FCP. Rendering out ProRes clips. I used the ‘Normally Scaled Legal Video’. When they bring in the ProRes files I rendered, there is a luma warning on the clip in Final Cut.

I spoke to someone at Resolve, and they told me that Normally Scaled will output renders in scaled video. So Final Cut is telling me it isn’t. I wish I had an outboard monitor; one cost at a time though, ya know?

[William Edwards]

So for ProRes, should I use the Soft Lut 64-940 with ‘Data Level’ or ‘Full Scale’?

(Now I don’t even know why Normally Scaled is even an option.)

[Stig Olsen]

If you finish in a NLE you can monitor normal range in Davinci, but output full range. When you import the files into your NLE you choose RGB when importing the clips and it will automatically remap the full range signal to normal range. No need for a LUT.

Since the NLE is working internally with levels between 16-235 you need to export with RGB checked to see what you see on your computer screen in Davinci.

If you finish in Smoke or Flame you can still monitor normal range, and export full Range in Davinci. Smoke and Flame also work full range internally and you can the same way set the output monitoring to normal range.

Stig

[William Edwards]

hmm…because Avid you’d want to import with 709, not RGB. I’m not the person doing the Final Cut conform, and I didn’t know you could do RGB import.

[Stig Olsen]

What you need to understand about Avid import is this:

– If you check RGB when importing, you tell Avid that you are importing a RGB file. It then remap the RGB file to 709 (16-235) that is what Avid prefers.
Some think that it works the opposite way – that Avid will import the file and remap to or keep it RGB, but that is wrong.

– If you check 709/601 you tell Avid that the file is 709 and it will NOT remap. It will eat it as it is (if it is 709)

Stig

[Stig Olsen]

.. so that basically means for you that you can monitor normal range in Davinci, render full range and import the file as RGB in Avid. Avid will then remap the full range file to normal range and your monitor will display exactly the same both in Davinci and Avid.

Stig

[Robbie Carman]

Alexis did a great job explaining this in the new revision of the manual so be sure to check it out (pages 167 to 169).

So from your original post it seems like you’re working with REC 709 Y’CbCr footage and not 4444 RGB? So ProRes HQ or something similar?

If so I’ve done nearly 160 hours of shows this year with the workflow I’m about to describe using ProRes HQ source files > grade and resolve and render > back to FCP for audio/graphic remarry and for output and layback. And everything has been fine.

There are two separate issues going on. First in your config (for both monitoring and deck) there are two options – video levels and data levels. WIth these options the important thing to remember is that it should be set to what your monitor or deck is accepting. So if your working with an FSI monitoring REC 709 you should leave this set to Video Levels.

While the internal scopes are always going to show full range in Resolve if you pop open your scopes on your FSI or an external set of scopes in the SDI path you’ll notice that the original footage that you perhaps looked at in FCP and saw a ton of under/overshoots are now clipped. However because of the internal processing of Resolve that data should be recoverable while grading.

On render in the delivery page simply choose Auto or Normally Scaled in the levels pull down and render the show. Send the XML over to FCP and things should be fine.

Easy way to test this create a white field over 100% in FCP or a gradient. Something you know is illegal and has over shoots/under shoots. Bring it in and render with the workflow I described and things should be ok. Again for broadcast ProRes stuff this is my workflow day in and day out.

A couple things to note:

1. Even with Video Levels and Normally scaled render its still entirely possible to get RGB Gamut errors (really only way to measure this is on a scope like the TEK diamond or the Harris Eye) but you can “sorta” see it on an RGB parade if you have overshoots/undershoots. To be honest you have to push it to have this problem but its still the reason that we run thru a Harris DL 860 for tapeless or tape outputs really mainly to ensure RGB legality. Resolve with the workflow I’ve discribed seems to do just a fine job at protecting Luma and Chroma and to a certain degree composite levels (although another reason to have the legalizer).

2. The Luma warning in FCP – was in the yellow warning sign or the green one? I can’t remember the exact levels off the top of my head but if its the green one thats normal just shows you there are levels between (I think) 90-100%

3. Finally, when it comes to RGB 444 data thats another can of worms entirely. The workflow does become slightly more complicated simple because there are times when you want to monitor for example 709 and Video levels but layback Full Range. Please read Alexis excellent write up on some of the scenarios in the manual.

Robbie Carman
—————-
Colorist and Author
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[William Edwards]

Thanks for clearing this up with Avid. I never saw this kind of import option for Final Cut; is there one? (I’m talking FCP 7, it’s what people are using for this project) (Is there something new in the newer FCP versions?)