Vari-Focal

Varifocal cameras are cameras that have adjustable lenses. Focal length of a camera is measured in millimeters and represents the distance of the lens from the camera sensor. The closer the lens gets to the sensor, the wider the camera view becomes. Most adjustable lens cameras have a range of 2.8mm to 12mm, but some cameras designed for longer distances will have higher millimeter specs (like 8mm-32mm). Pan Tilt Zoom cameras, while technically have variable focus lenses, they are in their own category.