4k footage in a 1080p timeline slightly blurry

Is it normal for 4k footage in a 1080p timeline to be slightly softer (blurry) than the original 4k browser footage?
When I compared the rendered and exported 1080p clip to the 4k clip, the 1080p is still slightly softer.
The view quality is set to Better Quality in Fcpx .

Also I did the same test In Davinci Resolve and the 1080p footage rendered without any quality loss.

If you are using proxy mode and export with proxy enabled it will be softer. If using 4k in a 1080p timeline without proxy, the export should produce good quality 1080p. It obviously will not contain the full detail of 4k because it's not 4k -- it's 1080p.

If using 4k in a 1080p project and you crop/zoom into the frame, then export at 1080p, the underlying 4k resolution will be used to produce the 1080p output. IOW you can crop/zoom much deeper than is possible with a 1080p source.

Non-cropped 4k in a 1080p project, not using proxy, exported as 1080p should look similar to that same content exported from Resolve.

I suggest you (1) Verify you are not exporting from FCPX with proxy enabled, then (2) Verify the video file characteristics of the exported 1080p files from Resolve and FCPX. A good utility which enables side-by-side comparison of various video files attributes in a spreadsheet-like fashion is Invisor: itunes.apple.com/us/app/invisor-media-fi...or/id442947586?mt=12

We use 4K in 720 and 1080 timelines for broadcast weekly. Sometimes, depending on focus and content, yes, the 4K can become softer. 4K requires very precise focusing, or it will exaggerate any off focus area when using it in HD timelines, especially when you set Spacial Conform to None to get that artificial zoom. Not always, but content with lots of contrast and sharp line details, yeah, I hate using that stuff from 4K.

Our 4K footage comes from GoPros, Phantom drones, and Blackmagic cameras. So we work with a variety of 4K "quality" also.

Yes, 4K in a 1080p timeline will be softer than the original 4K footage looks because you are throwing away 75% of the picture information to squeeze it down to 1080p. But it should look perfectly fine for 1080p. Imagine taking a photo 20 megapixels big with a DSLR. Now shrink it down to 640 x 480. Is it softer than the 20 megapixel original? You bet it is!!

I just hit this problem. In the past I have generally cut in a 4K timeline and then either downscaled on export or through compressor with good results. I finally convinced a production company I work with to switch to FCPX for some projects and this happens. None of the reasons below make sense. This should not happen. Editing in a 4K sequence and exporting 1080p is fine, but 4K in a 1080p sequence produces blurry images. That includes exports, by the way. I did a test and side by side the difference is easily discernible. Anyway, that is the only fix I could find. Also, just to head off questions: playback is set to better quality and I am not using proxies.

Daniel Rutledge wrote: ...Editing in a 4K sequence and exporting 1080p is fine, but 4K in a 1080p sequence produces blurry images. That includes exports, by the way. I did a test and side by side the difference is easily discernible...

I see a difference but it appears very minor. Here is a side-by-side comparison of 4k in a 4k timeline exported at 1080p vs 4k in a 1080p timeline exported as 1080p. Frame capture is from Quicktime 10.5.

Also when I scale both 200% within FCPX before exporting at 1080p, the situation reverses. I also tried spatial conform = none instead of the default of "fit". In that case the 4k timeline must be scaled by 200% to produce the same framing as the 1080p timeline. There is a tiny difference but in this case the 1080p timeline is slightly sharper.

joema.smugmug.com/Photography/FCPX-4k-in...in-1080-TL/n-TSKxJN/

Material: UHD 4k Sony XAVC-S 8-bit 4:2:0 100 mbps
Export option: Master File>Computer>H.264 Better Quality
Spatial Conform: "Fit" (except for last two which used "none").
MacOS 10.14.3
FCPX version: 10.4.5
Apple Pro Video Formats version: 2.1

So as I dig further into this, I am finding that some factors can make a difference.

There is only a noticeable difference with Multicam clips. I put 4k clips into a 4k Multicam clip and then edited that in a 1080p timeline and got blurry results.

Synced 4K clips and native 4k clips in a 1080p timeline seem crystal clear.

Native ProRes clips from an Atomos are much blurrier than XAVC clips.

When a clip is set to 100% (so downscaled from 4k to HD) it appears extremely blurry. But if you set it to 200% (1 to 1 pixels) it is clear. The closer to 200% you are, the better it looks.

Daniel Rutledge wrote: ...There is only a noticeable difference with Multicam clips. I put 4k clips into a 4k Multicam clip and then edited that in a 1080p timeline and got blurry results...

Even using a multicam clip in a 1080p timeline, I just don't see a major difference, and no difference between the MC clip and the single-camera clip. There is a slight difference (between 4k in 4k TL exported as 1080p vs 4k in 1080p TL exported as 1080p), so I think there's a valid question why any difference at all.

Also I don't understand why you're seeing such a major difference. Are you on 10.4.5 and using the latest version 2.1 Pro Video Formats?

4k XAVC-S MC clip in 1080p timeline, output as 1080p: photos.smugmug.com/photos/i-WBrbpT8/0/98.../X3/i-WBrbpT8-X3.jpg

4k XAVC-S MC clip in 4k timeline, output as 1080p: photos.smugmug.com/photos/i-WmZqXZK/0/62.../X3/i-WmZqXZK-X3.jpg

I edit 4K in a 1080 timeline (4K only for fake zooms/pans), and we never have image quality issues.

FCPX.guru wrote: I edit 4K in a 1080 timeline (4K only for fake zooms/pans), and we never have image quality issues.

It may vary with codec. There were definitely differences on XAVC-S between exporting to 1080 from 4k in a 4k TL vs 4k in a 1080 TL. However it was so minor it took A/B switching of frame grabs to see it.

Since much distribution today involves uploading for streaming web playback (which gets re-encoded), I'd be interested if anyone could see the difference during web playback on a 27" screen.

Premiere doesn't seem to do this but their own docs say they add sharpening when downscaling 4k to a 1080p timeline.