If you’ve been searching how to enable the camera on a Mac but haven’t been able to find anything useful, that’s because the built-in iSight camera doesn’t have an on and off switch — neither physical nor software. The camera is activated by apps.
How to Force the iSight Camera to Activate
Mac cameras activate automatically. However, the automatic activation process sometimes fails, leaving you without any obvious option how to turn on the camera manually.
To turn on the FaceTime camera on your Mac follow these instructions:
1. Open Terminal from Applications > Utilities.
2. Click inside the terminal window and type:
sudo killall VDCAssistant
3. Hit Enter on your keyboard. You may be prompted for your password. If so, enter the password and hit Enter again. You won’t see any confirmation message (unless something was typed incorrectly).
4. Open any app that uses the camera (FaceTime, Photo Booth, Zoom, etc) and your camera will turn on.
Disabling Completely the iSight Camera
Keep in mind that no apps will be able to use the hardware camera at all once this is complete unless you undo these changes.
1. Let’s start by creating a relatively hidden backup folder for the file. If you don’t want the folder hidden from the GUI, just remove the . in front of the directory name. Launch the Terminal and type the following command:
2. Next, we will move the QuickTime component that allows the iSight to be accessed into the backup directory we just created. Type the following command:
sudo mv /System/Library/QuickTime/QuickTimeUSBVDCDIgitizer.component /System/Library/QuickTime/.iSightBackup/
(In case it’s not clear, there is a space between the two directory paths)
3. Reboot the Mac (a reboot is required to unload the component)
4. That’s pretty much it, if you want to enable the iSight camera again, simply move the QuickTimeUSBVDCDIgitizer.component file back into the main QuickTime directory at /System/Library/QuickTime/