You can play back video from your projects and Events (source video) in full-screen playback mode, which uses your entire display. If you don’t use full-screen playback mode, your projects and Events play back in the viewer.
To set your full-screen playback size:
iMovie offers four options for full-screen playback size, which you set in iMovie preferences.
Choose iMovie > Preferences, click General, and then make a choice from the “Full-screen playback” pop-up menu, listed below.
(The iMovie menu appears in a light gray bar across the top of your computer screen.)
Entire Screen: Fills your viewing screen with the movie.
Entire Screen - Reduced Resolution: Plays the movie at a lower resolution for increased performance.
Actual Size: Plays the movie at the size of the original video.
Half Size: Plays the movie at half the size of the original video.
If you’re viewing high-definition (HD) video, you may not see differences among the largest three settings, unless you’re viewing your video on a very large display.
To play your video in full-screen playback mode:
Click to select a project in the Project Library or an Event in the Event Library, or open a project so that it’s showing in the Project browser.
Do one of the following:
To play a project or Event from the beginning, click the Play Full-Screen Playback Mode button (shown below) below the Project Library or Event Library, or choose View > “Play in Full-Screen Playback Mode.”
To play the project or Event from where the playhead (the red vertical line) appears in the Project browser or Event browser, press Command-G.
Move your pointer to reveal a filmstrip and buttons at the bottom of the screen; use these buttons to browse and play video as follows:
To play the project or Event, click the Play button. Click it again to pause playback.
To show only the filmstrip for the project or Event you’re watching and hide thumbnails for other videos (which appear on either side of the filmstrip) click the Cover Flow button.
To switch between browsing Events and projects, click the Events/Projects button.
To have the filmstrip and controls show at all times, click the Filmstrip button (so that it’s gray, not blue). If the button isn’t selected (so that it’s blue), the filmstrip and controls disappear a few moments after you stop moving the pointer.
To leave full-screen playback mode, press the Escape key.