[Scott Clements]

Thanks guys!

Nina, what do you mean about “edit posts”?

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

I am transcoding from ProRes 4444 to DNxHD 115 mxfs. I then put the mxfs in a numbered avid folder, rescan and put the database file in an Avid bin.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

Hi, Glenn.

I understand.

My Avid project is not BGB, but YCbBr 709.

Here are more experiments I did that I posted in the Avid forums:

If I remove the “Levels scaling (video levels to full range)” color transformation from the AMA-linked ProRes 4444 clip and still keep the rec 709 Lut applied….

And then render out a flat transcode from Resolve, with no LUT applied and bring it into Avid…

I can only get the flat transcode to match the AMA clip, if I change it’s source settings to add the rec 709 Lut and then the “Levels scaling (full range to video levels)”

But, if I just bring in the AMA and the flat resolve transcode and then just apply the rec 709 LUT, they look different

And this is the kicker….I can get the flat resolve transcode to match the AMA-linked defaults (of video to full, followed by rec 709) if I change its source settings to this: Levels scaling (video levels to full range), then I add the rec 709 LUT, then I add Levels scaling (full range to video levels). That’s 3 separate transformations.

Weird. I don’t really know what all this means. I am thinking of rendering out flat Resolve Transcodes as an emergency backup.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

Hi, Glenn.

None of these approaches in Avid match any output of resolve. I have tried everything. The only thing that matched the Resolve transcodes was this: removing the first color transformation that AMA made automatically : 1. Levels scaling (video levels to full range). I left the 2nd color transformation: 2. ARRI 709.AML (embedded). This made the transcodes from Resolve match the AMA clips. Even though I left the Resolve transcodes set to Auto, I did tests were I switched to Video, which did nothing and Full, which made the transcodes even darker than the AMA defaults.

People on Avid forums said that the first color transformation should not have been added because Arri ProRes is always at video levels.

This is all a total mess though. If it is true that the AMA default settings are wrong, then Arri made a bad Avid AMA plugin.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

Someone in the Avid forums told me I should not have the “Levels scaling (video levels to full range)” color transformation on the AMA-linked clips. Avid does this by default.

When I removed that color transformation, the AMA-linked clips matched the look of the Resolve transcodes exactly.

This seems to me to mean that Resolve was handling the footage correctly, but Avid was forcing an uneccessary transformation onto the footage.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

Thanks, Dennis.

Sorry, I can’t get the quote feature working here, so improvising. Here’s what you said: “The Arri camera records Prores 4444 XQ, which is 12 bit RGB. The problem you are having is likely due to the RGB or as Avid now calls it, Full levels, being interpreted as REC 709 or in newer Avid speak – Legal Range. So, it is lifting black from 0 to 16 and dropping white from 255 to 235, which is correct for REC 709, but not for RGB. You end up with a lower contrast image than what is correct.”

Actually, the AMA-linked version, which appears to set the blacks at 16 and the whites at 235′ makes a higher contrast and darker image than the resolve transcodes, which appear to have their blacks lower (at 0?) and whites higher (255?).

Here’s the waveform of the AMA-linked footage in Avid:

Here’s the waveform of the grade before it leaves Resolve:

Unfortunately, when I export the Resolve grade as an MXF and bring it into Avid, the waveform also has the black sitting around 16, so I’m not really sure what’s going on.

You also said: “If you are linking and transcoding in Avid, go to the source settings for a clip and try changing the GFX-Video Level settings to where you see black and white on the indicated baselines.”

I tried changing, based on your picture this and it did nothing to the appearance of the AMA-linked clips.

I have no idea how to make heads or tails out of this. I don’t know what is considered correct.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

There is a switch for Video and Full Data in Resolve. I believe I tried switching it (I’ll try again) but read an article saying that you almost never have to change it from auto. Regarding SMPTE bars – I’m super rusty on all that stuff – wouldn’t really know what I was looking for.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

Someone told me about the Arri Color Tool and I think I figured out how to export the embedded LUT from the original ProRes 4444 and then brought it into Resolve. However, the transcodes are still lighter than the transcodes done to the same original ProRes 4444 footage in Avid. I can’t figure out what’s causing the difference. Not sure if I have my project settings wrong, but I’m mostly using the defaults.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

Sorry for the delayed response, Lorrin. I didn’t have any luck with this. I’ve been working on an Avid show for quite some time, so have stepped out of that territory for the time being.

Film Editor, London UK
http://www.scottclementseditor.com

[Scott Clements]

Great! Thanks, Kalleheikki! That’s works very well. I wish creating a blank page was easier than making a fake blank page with Word or something, but that’s relatively easy to do.

Film Editor, London UK
http://www.scottclementseditor.com