Security Cameras
There are a multitude of features that are contained in modern security cameras and we will touch on a number of them here.
- Resolution – is usually measured in the number of TVL or Television lines supported by the camera. With the advent of IP cameras, you will now also see cameras rated in mega pixels.
- Infra-red LEDs emit light that is not visible to the naked eye in order to illuminate an area covertly. Many video cameras see infra-red light and use it to render better images in low light conditions.
- Day-night cameras usually refer to cameras that filter out the infra red light during the day so as not to distort the colors when lighting conditions are good.
- Vari-focal refers to lens that can be adjusted to zoom in or out depending on the desired field of view.
- Weather-proof is normally expressed by an IP rating such as IP66 or IP68, in general the higher the IP rating, the higher extremes in temperature and moisture, the camera can tolerate.
- PTZ stands for Pan, Tilt, Zoom. These are basically robotic cameras that can be controlled remotely to change the direction they are aiming and to zoom in and out.
- A bullet camera has a fairly thin tubular body attached to a swivel for aiming
- A dome camera is a more compact and usually more rugged structure that is often enclosed in a protective housing
- Analog cameras are the traditional cameras with resolutions up to normally 680 to 700 TVL. They are connected to a DVR which in turn normally has IP connectivity to the network and internet.
- IP cameras typically have resolutions starting at around 480 TVL and going up to 1024 or higher in the multi mega pixel models. These cameras are often accessible over the internet directly without the use of a DVR.
- While the choices may seem confusing, determining the basic requirements of each camera helps narrow down the selection immensely.
