Thanks for the question. I understand you are experiencing issues with your built in camera. The following article provides the most relevant troubleshooting information:
Built-in iSight cameras
These steps are for iSight cameras that are built into a computer, such as the iMac G5 (iSight) or later, the MacBook, or MacBook Pro.
1. See if the issue is application-specific.
Try another application (iSight works with applications like iChat, PhotoBooth, and iMovie HD 6) to see if the iSight camera exhibits the same behavior in all applications. If it only happens in one application, try reinstalling that application.
2. See if the issue is user-specific.
Test your iSight camera in another user account. If the issue only occurs in one user, the issue would be isolated to user settings.
3. Find out if the computer recognizes the iSight
Check System Profiler (in the Utilities folder, inside the Applications folder). Under the USB header, check to see if the iSight camera is detected.
4. Reset SMC or PMU
If your built-in iSight camera is still not behaving correctly after trying all these steps, you may need to contact Apple or an Apple-Authorized Service Provider for service.