I'm trying to free up some hard drive space and am wondering...once I've completed the movie project and exported as an mp4 file, can I delete the project files? I would assume that if I did that, they would also still be in my Photos library?
Assuming that the project files originally were imported into iMovie from the Photos app, including from the iMovie sidebar, then deleting them from iMovie will not remove them from the Photos app. When media is imported into iMovie it comes in as a duplicate copy of the original. Deleting the files from iMovie deletes the duplicate. The original of the source media remains in its original location.
— Rich
Assuming that the project files originally were imported into iMovie from the Photos app, including from the iMovie sidebar, then deleting them from iMovie will not remove them from the Photos app. When media is imported into iMovie it comes in as a duplicate copy of the original. Deleting the files from iMovie deletes the duplicate. The original of the source media remains in its original location.
— Rich
It depends on how you got them there. If you exported out of Photos and into iMovie, than yes.
If you just used the Photos browser from inside iMovie, maybe not. I would try it on one to see what happens.
iMovie - can I delete files once I'm done?
