Choosing an iMovie aspect ratio and size


macrumors newbie
Original poster
Sep 3, 2015
I'm importing old 640x480 (4:3) videos into iMovie (10.1.14). When I place these files into the Timeline, the Project window is 16:9 (cutting off top and bottom of videos) and the finalized project is saved at 1280x720.

How can I set the project aspect ratio (in this case we need 4:3), or the finalized project size, (in this case I'd like to keep at 640x480, but may later chose to go 960x720 or 1280x960, depending on quality of video, if possible).

It's important that I preserve the aspect ratio since these are old medical videos. I'd like to avoid pillarboxing if I can.