stuck on 1080p for export

You might try again opening iMovie while holding down the Option and Command keys, and selecting to delete preferences. Sometimes that cures problems with export options, as you have found.

As you probably know, the resolution of a newly created project is set at the resolution of the very first video clip , not photo, placed into the project timeline. Subsequently added clips with different resolutions will not change the initially set resolution. Nor will deleting the first clip and inserting a different resolution clip change the initially set resolution. If you placed a 4K 30 fps clip as the first clip, then 4k will be the unchangeable resolution of the project. However, iMovie doesn't support 4k 60fps so you may get a drop down to 1080p there. Is your 4k at 60 fps? If so, that might explain the absence of a 4k export option.

For a surveillance video I would think that 1080 would be sufficient, but of course that is totally your call if you feel that the final video doesn't display with sufficient detail.

-- Rich

Hmmm. Try making a duplicate of one of your 4k videos and then, working with the duplicate, convert it to H.264, Mp4/AAC at 4k. Then drag the converted video into iMovie and see if you can get a 4k option.

You can do the conversion with the free download Handbrake, that you can get here:

https://handbrake.fr/

-- Rich

P.S. [Can't edit my original response.] I tried creating a video in iMovie, importing a 1920x1080 video file and exporting the movie as 480p. It allowed me to export it at 960x540, but the file size was almost twice the size as the original 1080p video, which defeated the purpose of shrinking the resolution to reduce file size.

If you are exporting at the Best Quality (pro res) setting you would get a .mov file that could be as much as 4x larger than the Mp4 file that you get with other settings. This is due to the larger bitrate of the pro res codec. If this is your situation try sharing out at the Good quality setting, rather than Best Quality, that will result in the smaller sized Mp4 file.

-- Rich

I have the opposite problem— I can't get Photos or QuickTime to export *smaller* than 1080p. In both apps, I have tried exporting to 1080p videos to 480p and the exported files are still 1080p.

Hi,

You may already have figured this out, but if not here's another thing that you can try.

Use the Image Capture app on your Mac to import the clips to your desktop. Then open one of the 4k clips with QuickTimePlayer but don't play it. Once opened in QuickTimePlayer go to View/Show Clips. A clip display timeline will appear below the screen display. Drag your other movie clips into the clip display timeline. Then do a File/Export As/4k. (Hopefully you will have the 4k export option.) You then should end up with a composite 4k video containing all of your clips.

I tried the above using two 4k 60fps clips. The exported result was a composite of the two clips at 4k 60pfs.

Just a thought.

-- Rich