FCP 4K export issues from 1080p project

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Level 3

561 points

FCP 4K export issues from 1080p project

I have worked on a FCP 11.x project where I have footage in 1920 x 1080, other in 4K (drone and iPhone).

I followed tutorials to optimize for You Tube, and version 1080p, with Apple Pro Res 422 is relatively satisfying, ending up in a nearly 1 GB file.

I decided to give it a try : created a 4K project (3840 x 2160), then went back to my 1080 project, copied everything and pasted in the 4K project. Haven't changed anything. I then exported, and was surprised to end up with a smaller file (736 MB) for a 4K output (really showing 3840 x 2160).

While I would have expected the latter to have better quality despite smaller file, at at least one place, windows shape on a building show shaky (I'll call it artifacts) while it's not doing it on the 1080p version! (I'd like to upload here, but unfortunately, the image insertion button here does not allow me to do so).

I then tried another way, adding H.264, yet 3840x2160, ending out with a 2.51 GB file, artifacts are still showing.

Tried to use ProRes 422, ending up in a 19GB file (!!!) and... artifacts still there!.

So I'm going to upload the 1080p version.

NOW: I am being told if the project was already started in 4K (even though I can bring in different formats), I would likely have avoided this. As I am heading for another personal project, just want to ensure I'm not shooting myself in the foot. Would this give a different result ?

Thanks,

Rob

Mac mini, macOS 14.8

Posted on Feb 25, 2026 6:52 PM

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Answer 1

terryb

Level 4

3,654 points

Feb 25, 2026 9:43 PM in response to lanstrad1

You essentially "started" in a 4K project when you copied and pasted everything from the HD project into it.

Scaling 1920x1080 HD footage up to 4K, depending on the type of material shot, can look less than ideal. FCP's upscaling is generally decent but If you need something better, there are upscaling software packages available. FidelityFuze is an FCP plugin I've heard of but haven't used. TopazLabs is another that gets good reviews and there are probably free AI upscalers available now. Just searched for "FCP upscaling" and even elevenlabs is now offering upscaling.

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Answer 2

Feb 26, 2026 3:37 PM in response to lanstrad1

So in the 4K version of the project, do the "artifacts" show up on the timeline? Was there some stabilization that was applied in the 1080p timeline that wasn't applied in the 4K timeline? I would check this.

Not that this has anything to do with your issue, but for upscaling, be careful with AI upscalers like Topaz. It's great for small increments, like 720p to 1080p. But you've gotta watch out because it WILL garble text and give it that "AI look" if you try to increase more than that. 1080p to 4K you might be OK, depending on the source footage. I wish FCP offered a selection of upscaling types like I think Premiere and Resolve do, not just wimpy bilinear. I'd love to see the same options that Photoshop offers, including Nearest Neighbor. But come on it's Apple, they treat it like grandma's NLE when it comes to options.

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Answer 3

BenB

Level 6

13,680 points

Feb 26, 2026 12:32 PM in response to terryb

Now, the most important question is, what are the required specs of your delivered product? If it's 1080, edit in 1080. If it's 4K, edit in 4k AND up-rez any and all assets that are not as large as 4K dimensions.

All that said, and I own Topaz and use it often, and love it, I did a test inspired by this thread.

10 second clip of my dogs playing outside (I'm a trainer in my retirement), so lots of movement, color, etc. I exported it as a 1080 H.264 clip. Then used PixelmatorPro (yes, it handles video clips) and Topaz to each make a 4K version H.264. Placed all three in an FCP 4K project, and exported that as a 4K H.264. To be honest, I had a hard time seeing any difference between any of them. I guess it depends on the quality of the original image.

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FCP 4K export issues from 1080p project

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