PTZ Motion Tracking Camera with Night Vision and Built-In Recorder
The technology used in home security surveillance systems has changed dramatically over the years. Video cameras used in surveillance systems today are smaller, better and cheaper. Up until a few years ago video footage was recorded onto VHS tape, but today DVR (digital video recorder) systems record video footage onto a hard drive. The price of home security surveillance system has come down dramatically over the last few years. A home security surveillance system consists of two main parts: the video recording device, and the surveillance cameras.
1. Surveillance Camera Technology
Surveillance cameras either use CMOS or CCD (charge couple device) chips to record video images. CMOS is used in cheaper cameras, and the video quality is not as good as CCD cameras. We use inches to measure CCD camera formats, and brighter images are produced by larger CCD chips. A CCD format of 1/4″ or 1/3″ is good enough for most situations.
A surveillance camera’s resolution is normally specified as the number of TVL (TV Lines) that the camera can produce. This determines how detailed the video picture quality is. A resolution between 350-400TVL is normally produced by surveillance cameras. The frame rate of a surveillance camera is the number of separate images that the camera can record per second. Most camera’s can record at 30fps (frames per second), and video below 30fps is not smooth and begins to look jerky.
A color surveillance camera is not as good as a black and white camera in poor lighting conditions. A camera’s sensitivity to light is measured in lux. A camera’s light sensitivity must be 0.5 lux or lower to be able to view images at night.
2. Surveillance Camera Lenses
The lens of a surveillance camera should match the CCD format of the camera – 1/3″ lenses should be used with cameras with a 1/3″ CCD format. Home security surveillance system cameras normally do not have the facility to zoom in and out, are are said to have a fixed focal length. Motorized zoom cameras are more expensive, and allow you to change the camera’s zoom focal length remotely.
3. Other Surveillance Camera Features
Some surveillance cameras include Infrared (IR) LEDs, which project an infrared light allowing you view video in complete darkness. These cameras can typically see between a a range of 10 to 50 feet in complete darkness. More expensive home security surveillance systems have cameras with a pan, tilt and zoom (PTZ) facility. To be able to pan the camera’s view left and right, tilt the camera’s view up or down, or zoom in and out, the camera must have a PTZ (pan, tilt and zoom) facility.
4. Surveillance Camera Housings
A home security surveillance system can have large, visible cameras, which are cheaper, have larger housings, and can deter criminals by being clearly visible. Covert (hidden) cameras are generally quite expensive, are very small, and are hidden in other objects, such as a light fixture. Cameras that have a PTZ (pan, tilt and zoom) facility are normally housed within dome cameras. Dome cameras are normally mounted on the underside of ceilings. Weatherproof security camera housings are used by cameras that need to be protected from the elements. Outdoor surveillance cameras need to be waterproof and to be able to withstand extremes in temperature.
5. Video Surveillance Monitors
Using a standard TV as a video surveillance monitor does not produce the best picture quality. Computer monitors produce better picture quality, and also offer an extended lifespan. If you want to display video from multiple cameras onto a single monitor, then a 15″ monitor should be the minimum size you purchase.
6. Video Surveillance System Recorders
Most home security surveillance systems today record video onto a hard drive and not VHS tape. This has several advantages. Firstly, you do not need to fast-forward or rewind a tape to go to a specific point in a recording – you can immediately go to that specific point in the recoding. Secondly, you can playback an earlier part of any camera recording whilst that camera is still recording.
Motion detection is a handy feature which is incorporated into some home security surveillance systems, which allows you to only record when motion is detected within a certain area. This will reduce the hard drive storage space requirements. The only advantage of purchasing a VCR system today is its cheaper price.
7. PC Based DVR Versus Standalone DVR
There are two types of home security surveillance system, PC based DVR systems, and standalone DVR systems. A PC based DVR system is quite cheap, and is run off an existing PC. An expansion board must be installed into the PC case, and the required software must be installed onto the PC. The problem with PC based DVR systems are that these systems are unstable and slow when compared to standalone DVR systems.
The recording on a standard DVR security camera system is done using hardware, and this eliminates software crashes that you sometimes get with the PC based DVR systems. DVR systems generally have better performance and reliability than PC based systems.
8. Considerations when buying a Home Security Surveillance System
Your first consideration is the quality of the video you want to record. This is the video frame rate (video smoothness) of the recordings, as well as the resolution of the recordings in TV Lines. The second consideration is the number of cameras that you will need for your home security surveillance system. Typically, an entry level system contains four cameras. Your third consideration should be the size of the hard drive of the DVR system. Low-end DVR systems come with 80 gigabyte (GB) hard drives, whilst top-end systems come with a 750GB hard drive.
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Tags: dvr security system, home security, home security surveillance, security camera