Lens Technology for Security Cameras

Security cameras lens specifications often reference varifocal or fixed lens. Each type of camera lens has advantages and abilities.

Let’s start with a definition of each:

Security Cameras With Varifocal Lens (Zoom Lens)

A security camera with varifocal lens lets the focal length of the lens to varied and is most often refered to as a “zoom” lens. Most security cameras with zoom lenses or varifocal lenses have, and probably should have, an auto iris feature (an electrically controlled iris).

  • Lets you monitor larger outdoor areas with one camera. The combination of auto iris and varifocal means you can watch a large area and only zoom in when action is detected.
  • Lets you easily adjust and optimize for available light conditions
  • Applicable in locations such as outside a main door or gates, outside parking lot, or other places where the lighting conditions continuously change

Security Cameras With Fixed Lens
A security camera with a fixed focal length lens cannot zoom its focus is fixed. A security camera with a fixed focal length lens usually allows more light to pass through the lens at a given focal length than a varifocal, or zoom lens. This can be important in low-light situations.

  • Allows fast action-stopping shutter speeds to be used in low-light situations. Fixed focal length lenses are sometimes the only solution for low-light video
  • Can only be used in fixed lighting conditions (indoors)
  • Fixed focal length lenses are usually sharper than their zoom counterparts
  • fixed focal length lenses are usually less expensive than their zoom counterparts
  • Often used in shopping centers, schools, libraries, and offices