Compound Clip doesn't render correct pixel aspect ratio

TLDR - How does one get a compound clip to render from a project with anamorphic footage, and preserve the same PAR as the source raw files upon export of the individual clips?

Long version - I'm working on a 20 minute film with the specs below. The editor requires my files round-tripped at source resolution, and the source PAR. Below are the acquisition and timeline specs:

Camera package - Red Komodo 6k
Atlas Mercury Lenses (DeSqueeze 1.5x)

5760x2160
Set x scale to 150% for manual desqueeze if needed.
File is 5760x3240 out of camera w/ 1.5 PAR

Deliverable should be 5760 x 3240 files w/ 1.5 PAR

Display Aspect Ratio - 2.667

For my timeline monitoring settings, I've found I must to set my display monitoring to be 4096 x 1536 (2.666 AR) to see the whole image on my EIZO and Sony client projector. For Rendering, I check the 'render at source resolution' in the deliver page, which yields the correct files (5760 x 3240 w/ 1.5 PAR with the *.R3D media)... but NOT compound clips.


If I bring a rendered R3D file (ProRes 422) back into resolve, it displays correctly, and the clip attributes verify the 1.5 PAR is maintained. However, if I bring a rendered compound clip back into resolve, I see the file has a 5760 x 3240 resolution, but the clip attributes show square pixels. It also does not display correctly, it appears zoomed out. If I zoom in by 1.5 in both X and Y dimensions, it fits perfectly. (I'll try take some screen grabs and send as a follow-up post).

If I set the PAR in the clip aspect ratio to be 1.5, it only stretches the X dimension and not the Y dimension and is clearly wrong.

Further, I know the compound clip sets it clip attributes from the timeline settings, but I am unable to specify a specific PAR of 1.5 for the media. The choices are only square, 16:9, 4:3, or cinemascope, not what I need. It also seems that resolve handles the de-squeeze automatically from the embedded metadata in the R3D files, likely derived from the 1.5 par shown in their clip-attributes., but manually setting this in the compound clip doesn't yield the same result - frustrating.

I'm unclear why also when importing the clip, it's default is to require a 1.5 zoom in both dimensions.

NOTE - when creating the compound clip, I did make sure to set my default timeline to be 5760 x 3240, because otherwise it doesn't produce the correct resolution for that clip as it's not referencing the de-composed clip's source resolution. But again, no way to specify the 1.5 PAR for the render, and I haven't found a way to manually edit the metadata.

I noticed with Mediainfo.app, that the rendered 422 R3D files show a *display aspect ratio* as 2.666 (correct), but the compound clip's display aspect ration is 16:9 (incorrect, but based solely on the resolution).

I can't be the only one who has to get the rendered footage back to an editor with the PAR in place, or is this an extremely rare workflow? Even so, it seems there should be some way to work around this, like it would be easy if there was an option for a custom PAR in the timeline settings, and not just those 4 choices.

Any suggestions would be super helpful. I try to show a feww images.

Slight correction, Resolve *is* displaying the rendered compound clip correctly, but only at 1.0 PAR, which I don't understand.. the source resolution is 5760 x 3240, which is a 16:9 aspect ratio, and needs to be de-squeezed by 1.5x horizontally.


Here are some example images, I believe I will have to send a couple posts due to a limit of 3 links per post.

The following are all quick screen grabs of my viewer on my apple studio display, of an example scene in the film, first frame of the clip.

1. This is the graded R3D file with 1.5 PAR as displayed with the timeline settings previously noted, set for render (5760 x 3240). * the image displays the same weather set to 'scale entire image to fit' or 'center grop with no re-sizing'. Neither of these would affect the PAR anyway.

LD-R3D-5760x3240-1.5PAR.png (781.12 KiB) Viewed 144 times

2. this is the compound clip, rendered, and re-imported. same resolution, but renders out with a 1.0 PAR

LD-CC-5760x3240-1.0PAR.png (821.17 KiB) Viewed 144 times

3. this is the compound clip again, if I try to manually set the PAR to be 1.5

LD-CC-5760x3240-1.5PAR.png (569.14 KiB) Viewed 144 times

Next post, I'll show some examples of what my grading monitor sees, when I set the timeline to accommodate the max resolution of the Eizo, fed via the Decklink card

Notice the first two images, are displaying at the correct deliverable aspect ratio of 2.666 (approx). I'm guessing that resolve is already applying the de-squeeze to achieve the display aspect ratio of 2.666 based on the 1.5 PAR, but I have NO idea how it's getting the correct result from the compound clip (same resolution as the rendered R3D file), but with 1.0 PAR?!). Also my editor is not seeing the image come into Premier Pro correctly for that clip.

Anyway, here are just two clips if they are helpful, whereby I set my timeline to be 4096 x 1536 partially for faster processing while grading, but more so to allow the signal to fully show the entire 2.66 image on my Eizo and client projector. This timeline setting is not used for rendering, nor was it used when I made the compound clip that I rendered, and re-imported to demonstrate in the previous images. What it does show, is in the 2nd picture, this is what my editor is saying he sees on his end with the full 5760 x 3240 resolution compound clip.. (zoomed out).

Here's the display of the R3D clip:

LD-R3D-4096x1536-T-1.5PAR.png (782.93 KiB) Viewed 136 times

and here is the display of the compound clip (rendered as 422, re-imported)

LD-CC-4096x1536-T-1.0PAR.png (399.92 KiB) Viewed 136 times

As you can see this is zoomed out in both x and y dimensions. It does fit if you scale up by exactly 1.5x, but have no idea why this is happening.

Last thing I to note, if I didn't already mention, is that I have no problems whatsoever, rendering the R3D files exactly the same way as the compound clip, as Pro Res 422, and bringing those clips back in does have the 1.5 PAR and they display correctly.

What I'm wondering is the following
1 - why doesn't resolve provide more PAR options for over-riding the timeline
2 - how does resolve know to de-squeeze both 422 renders of the R3d file and the compound clip correctly to yield a 2.666 display aspect ratio in my viewer, but these two files have the same resolution, and DIFFERENT PAR's ? (1.5 vs 1.0)
3. - is there some other way to force a compound clip to take on the underlying clip's 1.5 PAR? (I realize a compound clip can have two or more clips, maybe with different attributes, so it gets it's PAR from the timeline..but there isn't a way for me to override to get what I need).

Hopefully this describes the underlying problem adequately, I know PAR issues can be very tricky. Thanks for any help or suggestions here.