Best Practice when using 4k footage & exporting 1080p

[David Baud]

“I’d think that working in a 1080 timeline would be ideal for this, right?”

Maybe ideal for your purpose… but at least it makes sense to me?

“HOWEVER, there are times when I get an edit 80% of the way there in a 4k timeline and would rather not go through the process of converting everything to a 1080 timeline. Is this an unnecessary process?“

It depends what you mean by “converting“. In Premiere Pro you can copy the content of a timeline to another timeline with different settings. Depending if you have already applied some transforms to your footage, it may not copy the way you want it from one timeline to another, and you may have to redo your transforms after the copy…

“Will the quality degrade if I were to edit 4k footage in a 4k timeline and scale some footage to something like 200%, knowing the export will be 1080?“

Yes you will degrade the quality of your footage! This is why you want to start with your 1080 timeline settings… You always want to avoid scaling up past the resolution of your original footage… depending on the camera original footage, you may have a 5% to 10% margin if you particularly care how to scale, but in general, if you are concern about quality, it is a “no, no”

If you are not sure to understand, just check it for yourself and output 2 files with your two different configurations. Make sure to watch your tests on a screen that represent pixels for pixels your result (in your case, display your clip at 1920 x 1080 resolution). You can also do a difference matte between these 2 files in order to show only the differences.

[Bill Celnick]

My situation is a little different because, although most of my footage is shot 4K, frequently I will have some 1080p footage as well, and since at this stage I’m delivering in 1080p, my sequences are all 1080p.

I will select all the 4K footage in the sequence, and click “set to frame size” so that it’s all visible in the program window, and if I want to crop or pan the 4k footage, will simply rescale and reposition in the effects control window.

[Jon Doughtie]

I always ask myself, “What is my deliverable?”. If my finished product is 1080 (or even 720 still) that is how I set up my edit timeline. Then I don’t have to worry about conversion. And if I shot 4K, I have virtual zoom and re-frame options. If I don’t need to move or re-frame, I just right-click and use “set to frame size”.

That’s just me.

[Alden Ford]

I actually came here today to search for this exact topic, I’m in a similar situation. I have 4K and 6K footage, delivering at 1080p. I’ve found that scaling the footage into a 1080 sequence is a lot harder on my system than editing it at higher-res, so I’ve been editing in 4k, and playback is nice and smooth. A Cam was shot in 6K so we’d have room to punch in in post, so a huge number of our shots need to be punched in to 1:1 at 6K.

But David is right – it turns out that Premiere doesn’t resample your source footage when you export. I’m in trouble because we are not only using 4K sequences, but we’re also using nested sequences where the 6K is scaled down to 4K – so disentangling all the scaling is thorny.

Premiere’s upscaling is good enough that we didn’t notice we were losing quality until we did some tests.

But I did find a sort-of workaround, if it fits into your workflow. If you import your sequences in After Effects, they do refer back to your source footage. So if your sequence is simple enough, or if you were planning to finish in After Effects anyway, that may solve your problem.

[Todd Perchert]

If you already have a 4k sequence, you could always render a Prores (or high quality codec of choice – not h264) master file at 4k and use that master file to render out your 1080 deliverable. Most everything I do is meant for broadcast at 1080, even though most of what I shoot is 4k. So I use my deliverable size of 1920×1080 for sequence settings. Allowing me to zoom in to areas of footage and crop.