Hi kennykaitduhh,
Welcome to Apple Support Communities! I see that you're finding some issues with recording videos with Photo Booth, and I'd like to help as much as I can.
Checking over the Photo Booth User Guide, there isn't any time limit shown for length of recordings.
Verify that your MacBook Air is plugged into power while recording the videos, so low battery doesn't become an issue.
Energy Saver settings on your Mac should also be checked for both Battery and Power Adapter to rule out any interference.
Notifications that may have been received is something else to check.
Keep any device that contains a magnet away from your Mac's palm rest, to avoid unintended sleep.
If you're still unable to determine why this is happening, contact Apple's Photo Booth experts to look further with you. Contact Apple Support > Select Apps & Software > Mac Apps > iMovie for Photo Booth videos.
Have a great day!