As with regular surveillance cameras, the lens on a surveillance camera determines how wide an image is created and how much light is let in.
The lenses you purchase should match the format of your surveillance camera: 1/4" lenses work best with 1/4" cameras. It is possible to use a larger format lens than the surveillance security camera calls for, but it is not recommended.
Also, fixed focal length lenses offer only one set field of view and are the least costly. To change the resulting image, you need to use a different lense. Variable focal length camera lenses and zoom lenses offer greater flexibility, allowing you to adjust your image's field of view. Motorized zoom lenses, the most costly type available, give you the ability to control your cameras remotely. If you want to zoom out for general surveillance and in for detail when you spot suspicious activity, motorized camera focus is preferable.
If you will be using the surveillance camera outdoors, look for a lens with an automated iris. As in the human eye, the iris of a lens is what controls the amount of light coming into the surveillance camera. Automated irises can significantly improve performance for outdoor cameras, where light levels vary considerably. However, you can save money and use a manual iris lens when the scene illumination never changes, for example in an illuminated store or office, but we do not recommend it.
Dome housings like this protect PTZ cameras and hide their orientation.
Pan, Tilt, Zoom
For advanced security applications, you may want a pan, tilt, zoom (PTZ) camera. With the right equipment, a camera operator can pan (scan left and right), tilt (look up and down), and zoom in and out. The significant catch is the cost: PTZ systems are a higher cost than fixed cameras, however most users find them the most effective for surveillance.
Camera Housings
Cameras need to be protected from potential harsh elements. Housings can range from simple coverings, to impact-resistant protection, to outdoor housings that include heaters and blowers for cooling. A more specialized type of housing is the dome: tinted Plexiglas hemispheres that prevent subjects from seeing which direction a camera is pointing. Choose the right housing based on the placement of the surveillance camera and its expected usage.
