Hi hopi krishna apple forums!
I have an article for you that can help you troubleshoot this issue. That article can be found right here:
How to Troubleshoot iSight
http://support.apple.com/kb/ht2090
Specifically, you will want to follow these first steps which talk about troubleshooting the built-in camera(I've included a few corrections in the article to make it more relevant for your operating system):
Important: Follow these instructions in order. Test the camera between steps to see if the issue is resolved.
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.
- See if the issue is application-specific.
Try another application (iSight works with applications like iChat, PhotoBooth, and iMovie) to see if the iSight camera exhibits the same behavior in all applications. If it only happens in one application, try reinstalling that application.
- 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.
- Find out if the computer recognizes the iSight
Check System Information (inside the Applications folder). Under the USB header, check to see if the FaceTime HD Camera is detected.
- Reset SMC or PMU
Reset your computer's SMC or PMU, and then check System Profiler again. (SMC reset instructions for iMac G5 (iSight), Intel-based iMacs; PMU reset instructions for MacBook and MacBook Pro.)
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.
While most of the relevant information will be contained in this article, I want you to follow the instructions listed above, because I have included some corrections to that article so that you will be able to troubleshoot more quickly and efficiently. Thanks for being a part of the Apple Support Communities!
Regards,
Braden