There is no standard lens for our security cameras. Some varieties of security cameras will use one type of lens, while another variety will use a completely different type.
In general, lenses can be classified as either fixed or varifocal. Fixed lenses cannot change their field of view while varifocal lenses allow for field of view adjustments within a range. A further important distinction between different types of lenses is the focal length. The focal length (measured in mm) determines the field of view. A shorter focal length will have a wider field of view while a longer focal length will appear more narrow and zoomed in.
For example, our ultra-wide security camera uses a 2.6mm fixed lens. On the other hand, our motorized varifocal cameras can adjust their field of view anywhere between 2.8mm (wide) and 12mm (narrow). This allows you to choose either a wide angle view, which will let you seen most of the scene in front of the camera, or a narrow, zoomed in view of one area in particular.