If your built-in camera is an iSight HD model/version, the answer is YES. Just open Quicktime > File > New Movie Recording (Your iSight Camera should turn on automatically). Then click on the little triangle (next to the record button) to bring up more options and under the quality settings, just select HIGH or MAXIMUM.
If you don't have a built in iSight HD camera, I believe the answer is No. You may need to crop the recorded video aftwards with third-party software, such as Handbrake (free video-encoding software).
Neither QuickTime nor Photo Booth can make native recordings in 16:9 aspect ratio.
iMovie versions after iMovie 5 can. (Select 16x9 when creating a new project.)
Software controls all Macs' inbuilt cameras. For info on recording formats for some
common apps, see http://discussions.apple.com/message/18535582 When comparing
your Mac apps, use these relationships for Aspect Ratio ("16x9") versus Size Ratio (16÷9) :
Aspect Ratio Size Ratio Application
16x9 1.777778 Hi-Def
1920x1080 1.777778 1080p Hi-Def
1280x720 1.777778 720p Hi-Def (iMovie)
1280x1024 1.250000 QuickTimeX (max)
720x480 1.500000 FaceTime
1280x853 1.500586 Photo Booth
640x480 1.3333... iChat