Why do I see visible lines or flickering in my webcam image, and how do I fix it?

Visible lines are typically caused by an incorrect line frequency (anti-flicker) setting. In HP Webcam Control Center, go to Settings, then Advanced Settings, and select the correct value for your location — either 50 Hz or 60 Hz. An incorrect setting can cause unwanted lines to appear in the image. (Page 9 and 11)