As the name implies, what gives Pan/ Tilt/ Zoom cameras their range is the combination of
- A motorized pan/tilt camera head with enough left/right horizontal range (pan) and up/down vertical movement (tilt ) to cover a large area plus…..
- A high-resolution lens that can zoom in to discern detail and zoom out again.
PTZ cameras go to extremes to capture an image. Unlike a fixed camera, they provide an adjustable field of view that can cover a wide swath of a shopping mall, then zoom in to focus on a group of people or even a single face. In terms of budget-sensitive surveillance, this means one PTZ camera can often replace up to four fixed cameras.
The zoom capability can be optical, digital or a combination of the two. With optical zoom, the lens actually moves in to zoom closer to an object of interest and enlarge it by virtue of proximity. Digital zoom enlarges an image after it has been recorded. Optical is preferable since the resolution of the image is preserved whereas, with digital zoom, the quality can be diminished by zooming in too close resulting in a pixilated image.
PTZ cameras are a useful addition to any IP surveillance camera system in that they can be used in both indoor and outdoor applications.
Outdoor PTZ cameras are built with sturdy, enclosures that include heaters, blowers, and sometimes IR illuminators.
Indoor models are less expensive and optional mounting brackets are available for attaching the cameras to a wall, ceiling, pole, or parapet.
PTZ Dome Cameras
Domes provide protection for the camera and can be clear, transparent, or opaque for discrete operations. The cameras have an auto-flip feature that kicks in when the camera is viewing something directly beneath it, allowing it to rotate so that the person viewed remains upright in the image.
Then, and Now
Early versions of the PTZ camera were slow to catch on. Some would-be users were put off by their weight and size or the fact not only did they need to be connected to a DVR, but they needed multiple cables, one for video, another for controlling the PTZ, and a third to supply power. Thanks to built-in microcomputers, today’s IP PTZ cameras have a lot more intelligence than the old analog cameras and require only a single network cable rather than three. As for the DVR, it has been replaced with the NVR (network video recorder) or VMS (video management software) both of which add additional capability.
This is available in both the camera and the video recording system. Although most cameras do have built-in auto-patrol mode, using VMS (from OnSSi) brings an added benefit. The software controls the camera and when the software detects motion, it stops the camera and records the video. It also ignores motion (detection) when the camera moves from one position to another. This is a very important capability since it limits the amount of false motion detection alarms caused by camera movement.
For situations where surveillance is needed in both bright and lowlight situations, there are day/night cameras. These cameras operate in a wide range of lighting conditions. They include IR filters and special IR lenses that assure that the image stays in focus day or night. For darker applications, there are night vision IR PTZ cameras that come with an attached long-range infra-red light illuminator that casts its light up to 650 feet and automatically adjusts its beam, angle, and intensity to fit the camera’s zoom.
The bottom line
PTZ cameras work best when someone is actively watching the video. Automatic patrol modes and analytic functions work best when there is very little activity in the viewing areas.
When one person is walking through a parking lot, the camera can automatically record the video, but when there are many people walking through the lot the automatic PTZ mode will miss a lot of activity.
The downside of PTZ cameras is that they can be looking in the wrong direction and miss some important activity. In this case, it is better to use one or more fixed cameras.
Kintronics carries a variety of IP security cameras to fit whatever your needs may be Call 914-944-3425 to speak to a sales engineer or if you prefer, just fill out an information request form and someone will reply promptly.