Posts Tagged ‘ ptz’



What is a PTZ (Pan-Tilt-Zoom) Camera?

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Thursday, September 3rd, 2009

A PTZ (Pan-Tilt-Zoom) camera refers to the ability of a camera to move up and down (tilt), left and right (pan), and to magnify (zoom). Typically, the pan-tilt function is accomplished with a built in motor. The zoom function is accomplished either digitally or optically. The magnification of the camera is determined by multiplying the digital and optical zoom. For example, a camera that can optically zoom in 22 times (22x) and digitally zoom in 10 times (10x) is usually referred to as a 220X PTZ camera. Optical zoom is always preferred since this is a true zoom accomplished by the lens itself. The digital zoom is simply a virtual zoom and it usually will result in pixilation.

PTZ cameras can be controlled through by connecting a control or data cable between the PTZ camera and either a DVR or PTZ keyboard. There are many protocols available. The most common are Pelco D and Pelco P, but there are many more. It is important to make sure that your DVR is compatible with your PTZ and has the right protocol choices.

There are many benefits to using PTZ cameras. The most common benefit is the ability to cover a large open area using a PTZ where each PTZ can do the job of many standard cameras. Also, a PTZ can provide additional detail video coverage for other fixed overview cameras. For example, if motion is detected at the entrance of a parking lot by an overview camera, a PTZ can be triggered to zoom in to the entrance and cover it in great detail for a preset amount of time. Also, a PTZ camera can usually be put on a pre-configured tour acting like a sentry.

PTZ cameras are available in different styles included box cameras, bullet cameras and most common today are vandal domes. PTZ cameras can be installed outdoors if they are in a weatherproof housing or indoors in a ceiling or surface mount. They are available in different sizes. The smaller PTZ cameras are often called mini speed domes, while the larger models are just referred to as PTZ cameras. Newer PTZ cameras have recently become available with auto tracking built in. This feature allows the camera to move when tracking a moving object automatically.

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Surveillance System for a Parking Lot

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Wednesday, August 19th, 2009

It may seem challenging to attempt to properly cover your parking lot with security cameras. Just using overview cameras to monitor an entire parking lot will usually not be enough. Though the overview cameras will have a general overview of the area, unless you invest in megapixel IP cameras you will get very little detail. IP cameras are certainly an option , but megapixel IP cameras capable of capturing useful detail are fairly expensive. You can easily expect to spend several thousand dollars per camera and then have to deal with the bandwidth and storage issues.

The most economical option is to supplement the overview cameras with a few pan-tilt-zoom (PTZ) cameras. The DVR can be programed to trigger a PTZ to cover an entrance or exit of a parking lot when another camera spots motion there. This would allow you to capture great detail as a vehicle or person enters or leaves the parking lot. also, the PTZ cameras can be programmed to remain on a tour while there is no activity in key areas to cover the rest of the parking lot. There is also the option of motion tracking PTZ cameras that are capable of following moving objects in the field of view. Using this combination of cameras can actually provide more usable footage with similar detail as a megapixel IP camera, only it will save you many, many thousands of dollars.

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The Basics of RS485 and PTZ Control

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Friday, August 7th, 2009

Almost every DVR has the ability to control a multitude of devices using the RS485 protocol. RS485 uses 2 wires to send and receive data to and from these devices. All the devices in an RS485 “network” are connected in parallel with one another. This is a very simple form of communication and relies mainly on the address that is given to each device.

The most common type of device that would be controlled in a security surveillance environment is a PTZ camera. Each PTZ camera on the system must be given a unique identification number. The method of setting this number varies from camera to camera, but normally this is accomplished either by setting a switch on the camera or through the on-screen display or OSD. At this point, you should also take note of the baud rate of the PTZ and the protocol that the PTZ uses (Usually Pelco-D).

Once each PTZ camera is given a unique ID, then the DVR can be configured. Each camera on the DVR that will be controlled will have settings that need to be configured. Just match up these settings with the settings that are configured in the camera. At this point, you should be able to control your PTZ.

There are many other types of devices that can be controlled using RS485. The setup is identical for those devices as well.

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