Wed Feb 08, 2023 9:12 pm
I'll try to explain. First a couple of pre-cursors:
1. Timeline resolution and output resolution are two different settings. Usually the output resolution is set equal to the timeline resolution but they can differ. I typically setup my timeline so that it is different from the project settings (a checkbox you can uncheck when you first create a new timeline).
2. A compound clip's media resolution is set to the timeline resolution in which it is created. So if you have some UHD media and you put it on a 1080p timeline and then create a compound clip, the compound clip will have 1080p resolution.
3. If you set the scaling in #2 to crop / centered you will only see the center portion of the UHD clip and you can pan/scan then clip as long as you are working with the original media clip. As soon as you make it into a compound clip, the new resolution of the clip is 1080p and it is cropped to the timeline resolution (not the output resolution - this will become easier to understand shortly).
Because the compound clip is cropped in #3, when you drop it into another timeline, it won't allow for pan/scan to the original source UHD extents because it was cropped as a compound clip. This is the underlying reason I believe you get what you reported in your first post, if I understand your post correctly.
It's also worth noting that compound clips and nested timelines suffer from this same behaviour - if you drop a timeline into another timeline, it's pan/scan will be cropped regardless of the resolution of the source media on the dropped-in timeline.
One workaround that I found (and it's not perfect because there are some unusual side effects with things like power windows in the color page when applied to clips with Fusion effects) is to setup your timeline resolution to be larger than your output resolution and to treat the timeline resolution as a virtual workspace for you higher-than-output resolution clips.
For example, let's say I have some UHD material that I would like to place into a compound clip and then introduce into a vertical 1080p timeline. I would first setup a timeline with timeline resolution of 3840x2160 and an output resolution of 1920x1080 (both with the center-crop no resize scaling setting). Now I would place my UHD source onto this timeline and I can do some pan/scan to center my subject if desired (or hold off until I go vertical).
Now select this clip, right-click and convert to a compound clip. Even as a compound clip I should be able to pan/scan because the compound clip's resolution is timeline but the output resolution (the keyhole view) is smaller in this example.
Now create a vertical timeline with a timeline resolution set to 3840x3840 (or 2160x3840, possibly) but set the output resolution to 1080p vertical (1080x1920), again with both resizing set to center crop, no resize.
Now you can drop the compound clip onto the second timeline and its larger timeline resolution (i.e., workspace) will allow you to pan/scan in the vertical timeline the same way you would expect it to if it where UHD source material.
This is from memory and I can't recall if the vertical timeline really needs to have a timeline with larger extents than its output resolution. I also can't recall what limitations are imposed when applying this approach but if you have a specific workflow in mind, it might be worth your time investigating the ins and outs of this method.
Having posted this, I am going to grab my laptop and try this again to see if I can refine the steps.
Time Traveller
Resolve Studio 19.0b1 | Fusion Studio 19.0b1 | Win 11 Pro (22H2) | i9-7940x, P4000 (536.96, 8GB VRAM), 64GB RAM, M.2 boot, SSD scratch, RAID10 data | (laptop) 16" MacBook Pro M1 MAX, 32 GPU cores, 64 GB RAM, 2 TB SSD, Sonoma 14.4