Scaling 12K 17:9 DCI to 4K 2.4:1 cinema widescreen

Hello,

I am new to the forums and a complete novice when practicing Cinema-grade videography. Ive worked around for a decade in the Adobe Suite on SD and HD video so I understand the fundamentals yet the digital era has evolved since 2011 lol.

I have a project that was captured on the URSA MINI PRO 12K with a mix of these resolutions.

1) 12280 x 6480 17:9 DCI 24 FPS 5:1 C.B
2) 7680 × 4320 17:9 DCI 120 FPS 8:1,12:1 C.B
3) 6144 x 2592 2.37:1 120 FPS 8:1,12:1 C.B
4) 4096 x 2180 2.4:1 120 FPS 5:1,8:1,12:1 C.B

My questions are these.

1) In order to achieve maximum fidelity, is my best option to grade each specific clip and then export to the timeline setting of 4K, since that is the lowest resolution clips I have, so downsampling all other source files is a must? Or can I make a maximum resolution timeline and then export my project of all the different clips with their individual attributes of resolution to a 4K export (12K timeline is super bad on this Mac Mini M1 iGPU but everything else below that timeline resolution seems to work decently so I go with 8K)

2) What is the specific equation to convert 17:9 DCI aspect ratio to match the 2.4:1 aspect ratio; or is there a function is Resolve that I am unaware? I know the x & y scaling tool on the inspector yet when I mess with the position, it globally scales the entire frame rather than locally for the corresponding axis I am manipulating. (i.e: x and y dimensions)

3) I am usually going to be working with a combination of 12K/8K/6K footage, anytime I work within Davinci, is there any tips on time efficient workflow(s) to get the timeline reserved with maximum image fidelity and hassle free exporting processes without individually exporting each clip to the desired final project resolution?

I hope I am making somewhat sense and hope to hear back from you all!

, S1lent Productions

[Peter Chamberlain]

Generally, set the timeline res and frame rate in project settings to that of your final deliverable. Or the highest res if there are multiple.

Resolve will automatically scale higher res sources to the timeline, and higher frame rate to the timeline based on settings in project settings

+1
set timeline to match prime deliverable
set monitoring to match timeline

I also follow the advice above.

Generally, set the timeline res and frame rate in project settings to that of your final deliverable. Or the highest res if there are multiple.

Resolve will automatically scale higher res sources to the timeline, and higher frame rate to the timeline based on settings in project settings

So, bare with me ha.

If my desired final export resolution is 4096 × 2160 with the aspect ratio of 2.3:1 , yet my footage has a mix of 12K DCI, 8K 2.3:1, 8K DCI, 6K 2.3:1, 6K DCI, and so on; setting my time line settings to the export of 4K will down sample all my clips to the final deliverable?

On the export node, in advanced settings, there isn't a way to setting the aspect ratio, only pixel ratio between square and cinemascope; unless cinemascope is a default method to achieve the 2.3:1 cinema aspect ratio?

4096 × 2160 with the aspect ratio of 2.3:1

Those number's don't match.

You'd use 4096 x 1780.

setting my time line settings to the export of 4K will down sample all my clips to the final deliverable?

Not necessarily. Input Scaling will have an impact here.

4096 × 2160 with the aspect ratio of 2.3:1

Those number's don't match.

You'd use 4096 x 1780.

Okay so if the original source clip is at that resolution, to achieve the aspect ratio of 2.3:1; I would change the of “y” x&y; is that going to compress the pixels in DaVinci?

What is the equation you used to figure out the resolution dimensions?

setting my time line settings to the export of 4K will down sample all my clips to the final deliverable?

Not necessarily. Input Scaling will have an impact here.

When you’re referring to input scaling, are you referring to the original timeline resolution input or the source clips I’m working with? What I’m deciphering from everyone’s post is that if my final export is 4K, all I set my timeline project settings to that of 4K; then my source files, with 12K being the highest, will down sample automatically once imported on the timeline. Also my question is how does DaVinci establish the aspect ratio of 2.3:1 automatically from a 17:9 DCI source file to final export? My project contains both 17:9 and 2.3:1, my question is how do I match the aspect ratios for final export?

First of all, there's no such aspect ratio as 2.3:1. I think you mean 2.39:1. In this case, you'd divide 4096 by 2.39 to get 1714, though it's usually given as 1716. These would be deliver page settings: that's the way you achieve any given aspect ratio for export. Your timeline would also likely be set to these dimensions.

As for your first question, 12K 8K and 6K will be down-sampled to 4K on a 4K timeline, but the original resolution remains available, should you reframe the shots. So if you reframe a 12K shot on a 4K timeline, you're working from the original 12K resolution, not the down-sampled resolution.

For input scaling, you'd normally choose scale to fit.

First of all, there's no such aspect ratio as 2.3:1. I think you mean 2.39:1. In this case, you'd divide 4096 by 2.39 to get 1714, though it's usually given as 1716. These would be deliver page settings: that's the way you achieve any given aspect ratio for export. Your timeline would also likely be set to these dimensions.

As for your first question, 12K 8K and 6K will be down-sampled to 4K on a 4K timeline, but the original resolution remains available, should you reframe the shots. So if you reframe a 12K shot on a 4K timeline, you're working from the original 12K resolution, not the down-sampled resolution.

For input scaling, you'd normally choose scale to fit.

My mistake on the 2.3:1, I meant 2.4:1. Okay so it’s just the X dimension divided 2.3.

Everything else now makes sense, just need to practice more.

Only thing I’m still not getting is matching 12K,8K,6K 17:9 DCI to the 4K 2.4:1 final export. So I have to go to each clip and rescale to fit, and divide the x by 2.4?

use the scaleing option in the project setting that applies to the majority of media
at the clip level use the inspector's change scaleing options if the project setting is suboptimal for a given source

You need to be clear if you NEED 4096x2160 then you export eh crop for DCI 4096x1716 or you dont need the extra top/bottom for later use.

I recommend to keep it at 4096x2160 and just extract the final later so you have room for a 16/9 pass if you need that.

Having said that, it is probably recomended to scale everything at that 4K resolution and working as normal, unless you MUST preserve the original *that i dont see a reason for* you want to go from teh origianl resolution to teh final on e in one step only to minimize subsampling.