You can test your input volume by monitoring the 'Input Level' bar. The webcam is not recognized on Mac, I am using latest OS X.

Alternatively, you can click on another sound input device from the device menu to use it as your main input device. Doing so reduces the input volume to 0, and 'disables' the internal microphone from picking up sound. The fix in this case is to force-quit the VDCAssistant process, so relevant programs can again launch it normally and establish connections to the webcam. Drag the 'Input volume' slider all the way to the left. Ask any computer store what’s the most common issue customers experience, and they’ll likely tell you that it has something to do with cameras not. Type 'v4l2ucp' in the search box and then select it. Cameras and computers seem not to like each other. Now your webcam is working you can optionally (to improve the quality of your webcam picture), install v4l2ucp (video for linux 2 universal control panel) from the Software Manager.

When the camera is unavailable, you will see a 'no connected camera' error in programs and services that use it. Press Enter and close the Terminal, start Skype and webcam works. While this process should quit when the program stops using the camera, it may persist if an error occurs, and prevent future connections to the camera, either by the same program or by others. Nearly all apps that you can use on your Mac to access the camera have their own settings. When you run a program that uses your Mac's webcam, OS X will launch a background process called VDCAssistant, which manages the connection and control of the camera. It’s good to know that Mac’s operating system doesn’t have a built-in app that configures your webcam. OS X Daily has recently outlined one cause and fix for such problem. Do you regularly use your Mac's iSight camera for chatting and other purposes, and have you run into a 'no connected camera' error in the application you're using? If so, then a few causes and fixes are available that might help you out.

Turn on webcam mac terminal