USB based webcams usually supports dfferent resolutions for video and very often maximum is 640x480 (VGA). But that resolution is not using in most cases, we use only 320x200 or so for online video conferencing purposes, becuase 640x480 is too big for realtime video over the internet. That allows to do zoom and move camera. CamZoomer is a middleware application between webcam application and real webcam driver with tilt/pan/zoom features.