Apple's iMovie '11 (version 9.0) does not support external USB UVC camera by default, Webcam Settings iMovie Enabler (WSiE) enables that for Webcam Settings user. (Webcam Settings allows you to adjust settings including the exposure time, contrast, saturation, and white balance temperature for your webcam, whether it's a Built-in iSight, a more recent FaceTime/FaceTime HD Camera or an external USB webcam.)
Full Specifications
What's new in version 1.0
General
ReleaseNovember 27, 2012
Date AddedNovember 27, 2012
Version1.0
Operating Systems
Operating SystemsMacintosh, Mac OS X 10.6, Mac OS X 10.7, Mac OS X 10.8
Additional RequirementsMac OS X 10.6 or later
Mactaris Webcam Settings
Apple iMovie '11 (version 9.0)
USB UVC webcam