What is a PTZ Camera?
A PTZ camera is a camera with pan, tilt, and zoom functionality. These movements can be manually controlled by using monitoring software or a joystick, or automatically set up using camera management software. Being able to move the camera necessary by a security guard allows your security staff to respond quickly to events they spot with the surveillance system.
You can also use camera management software to set up guard tours, where the camera will automatically move to monitor pre-set locations on a schedule. Some cameras can also auto-track movement, following a person or car moving in its field of view.
How PTZ Works
Pan
The camera can swivel to the left and right, allowing it to have a wide area of coverage. Pan can range from a complete 360 circle to smaller areas.
Tilt
The camera can tilt up and down, giving it a wide vertical range of coverage. The amount the camera can tilt will vary by camera model but goes up to 180 degrees.
Zoom
Optical zoom physically adjusts the camera lens, changing the focal length to zoom in and out; this allows the camera to maintain image quality. The amount of optical zoom is expressed as #x, such as 18x, and represents how much the camera can zoom (change the lens focal length). Digital zoom blows up the image using software, often resulting in pixilated images when zoomed too far, and is not recommended.
Advantages of PTZ Cameras
Large Field of View: PTZ cameras are used to monitor a large area, and often recommended to use in conjunction with a fixed camera to avoid gaps in coverage. Depending on the model, cameras can move anywhere between zero pan/tilt and the full 360-degree pan/180-degree tilt. Some solutions also have digital pan and tilt, which allows for video to be adjusted after recording – though the resulting video would be grainer and lower res.
Motion-Based Auto Tracking: Auto tracking is a function that enables PTZ cameras to adjust their field of view to follow moving objects automatically. The use case for this function is typically best applied in quiet areas with minimal movement (for example, a museum after closing).
Time-Based Auto Scan: PTZ cameras can be configured with autopilot to scan pre-defined areas and move in patterns (tours). Pre-set positions can be programmed to change positions based on time. For example, a PTZ camera can be configured to pan, tilt, or zoom every 30 seconds to capture different areas of interest within the camera’s overall surveillance area.
Remote Camera Control: Conventional PTZ cameras can be manually and remotely adjusted to track suspicious activity. This allows users to change the camera’s field of view without having to go onsite.
Zoom Capabilities: Most PTZ cameras support optical zoom, which is used to view and capture faraway objects like license plates or faces. Optical zoom (ie: 20x, 30x, 40x) refers to the maximum focal length divided by the minimum focal length – the larger the number, the further the zoom.
Disadvantages of PTZ Cameras
Limited View: PTZ cameras are unable to record areas that the camera is not specifically looking at, which is a major con leading to gaps in coverage. Cameras can pan, tilt, and zoom to cover potentially huge areas, but not simultaneously. It is possible for incidents to occur and intruders to slip undetected from under the camera’s field of view (FOV).
Shorter Lifespan: Because PTZ cameras contain many moving parts (including motors to pan, tilt, zoom) prone to fail eventually, they are less durable than fixed solutions. Due to their high failure rate, the total cost of ownership tends to be higher than the initial camera price.
Surveillance Blind-Spots: PTZ cameras have a reputation to point the wrong direction, especially when set on “auto” or “home”. A camera may pan continuously to the next pre-set, regardless of what is happening in its field of view. The ideal way to use a PTZ camera is to have a guard always manning the camera, but blind spots are still a risk of human error if the controller is left in the wrong position.
High Cost: In many cases, a single or multiple fixed camera (such as fisheye cameras) can give more coverage at a lower cost compared to one PTZ camera. A 4K fisheye camera, for example, may be configured to cover the same area as a PTZ camera and permit digital zoom on high-resolution footage, without running the risk of being repositioned incorrectly.
Latency Sensitivity: A common issue that many PTZ cameras face is high command latency. The command latency is the lag time between which an operator issues a command to adjust the camera FOV, to when the FOV changes on the monitor. It’s important to be aware that high latency can sometimes cause PTZ controls to malfunction and shift out of gear.
High Risk of Malfunction: PTZ cameras that are not properly installed can lead to trouble from both a mechanical and legal perspective. On the mechanical side, camera hardware that is not installed correctly could malfunction under changing weather conditions. On the legal side, PTZ cameras that accidentally include even an inch of private property in their field of view could land the installer and owner in deep trouble.
Types of PTZ Cameras:
PTZ IP Camera: PTZ internet protocol (IP) cameras can be deployed via Wi-Fi or Power over Ethernet (PoE). Compared to traditional analog PTZ cameras Wi-Fi PTZ Camera: Wi-Fi PTZ cameras connect wirelessly to a router without a hardwired connection. (However, they still require a power source.) A strong Wi-Fi connection is also recommended to prevent issues with lag and video quality.
PTZ PoE Camera: A PoE camera uses an Ethernet cable that plugs into a PoE switch to receive power and an internet connection. It generally has a connection distance much more powerful than Wi-Fi.
PTZ Analog Camera: Analog (CCTV) PTZ cameras use an analog video signal to capture surveillance footage and are wired to digital video recorders (DVRs) via coaxial cables. Analog PTZ security cameras typically cannot transmit video data on their own and require a DVR to support converting, compressing, and saving footage.
Outdoor PTZ Camera: PTZ cameras that are deployed outdoors must be able to withstand more extreme temperatures and weather conditions. They are typically encased in a weatherproof exterior with an IP rating that indicates adequate protection against natural elements.
Wireless PTZ Camera: In cases where the installer is unable to run video cables, wireless PTZ cameras are able to transmit video wirelessly. Typically, this is done through Wi-Fi, although transmitter sets can be used to convert analog signals. Wireless PTZ cameras are typically deployed for long-distance outdoor monitoring where it is difficult or expensive to run cabling.
What to Consider When Buying a PTZ Camera:
- Will you have someone manning the camera at all times?
- Do you have sufficient storage? (Cloud, Hybrid Cloud, DVR, or NVR?)
- What visibility do you need? (3MP vs. 4K resolution? Field of view? Low-light IR illuminators?)
- What type of environmental hazards do you face? (Operating temperatures? Waterproof?)
- What does the installation require? (Supporting equipment? Professional system integrators?)
- What kind of cabling is needed to support the system in terms of network connectivity? (PoE, Wi-Fi, wireless?)
- How much pan and tilt functionality do you require? (Though a 360 pan may remove all blind spots, the corner camera would not need to record the wall behind it.)
- What environment will the camera be deployed? (Indoor, outdoor?)
- What type of camera best fits your needs? (Dome or Bullet?)
