What are Pan-Tilt-Zoom Cameras?

An alternative to fixed cameras, Pan, Tilt and Zoom (otherwise known as PTZ) cameras get their name because of their ability to pan left and right, tilt up and down, and zoom in and out of a picture plane. They can do this due to a unique combination of a pan/ tilt head and a zoom lens. The total zoom capability of a PTZ camera is actually a combination of digital zoom capability and optical zoom capability. Digital zoom uses electronics to zoom in and out while optical zoom uses lens motion. The total zoom of a camera can be calculated by multiplying the digital zoom by the optical zoom. As far as PTZ functionality, a keyboard and receiver is required to operate PTZ functions. Most PTZ dome security cameras have receivers built in to them, however.

PTZ cameras are made for both outdoor and indoor applications, adding to their versatility. Outdoor PTZ cameras have pan/tilt heads that are weatherproof, heavy duty, and more robust than their indoor counterparts. The reason for this is that they often need to carry heavier housings and accoutrements such as IR lights. Indoor PTZ cameras often employ housings made from plastic and are therefore lighter in nature.

A recent development in the history of the PTZ camera is the popularity of PTZ dome camera. They operate in the same manner as traditional PTZ cameras but differ in that both the P/T head and the control electronics reside inside the dome. The domes themselves range from transparent or semitransparent to opaque, making them suitable for even discrete applications. PTZ dome cameras have several advantages over traditional PTZ security cameras. Domes can efficiently move in all directions, including 360 degree rotation and viewing straight down. Dome cameras utilize auto-flip to view something directly below it. Auto-flip allows the security cameras to rotate automatically when something passes directly below it, ensuing that the object or person remains upright on the viewing screen.

Many PTZ cameras can be programmed with preset positions and can be made to survey these locations on a regular basis. The number of preset positions varies by camera manufacturer and model, but common presets average from 8 to 32 in number. The precision of a camera’s ability to return to a preset position varies based on the mechanics, electronics, and software used. In addition to preset positions, PTZ cameras can be made to operate only when a specific change occurs, such as a noise, motion, or a change in heat. This is done with devices such as motion detectors connected to the PTZ camera. In this way, recording times can be minimized to crucial events.

Furthermore, IP PTZ cameras come with a built-in IP address, enabling remote surveillance from anywhere in the world using a standard web browser. Users simply connect the camera to a network and they then can take advantage of many common software based features included with IP PTZ cameras, including a web server, an FTP server, and an e-mail client.

Another feature common to PTZ cameras is privacy masking. This provides the ability to mask certain areas in a camera’s view, such as a window or a door of a house. The position of the mask can interlock with the camera’s movements, so that if a camera pans, tilts, or zooms, the mask will reposition and resize accordingly to make sure what needs to be hidden stays hidden. This affords the user of the camera an escape from litigation due to infringement of privacy. s