How to Select a Home Security Surveillance System
Night Vision PTZ Camera with Built-In Recorder and Motion Tracking
The technology used in home security surveillance systems has changed dramatically over the years. Surveillance systems today have video cameras that are cheaper, smaller, and better. 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. The two main parts of any home security surveillance system are the surveillance cameras and the video recording device.
1. Surveillance Camera Technology
Surveillance cameras either use CMOS or CCD (charge couple device) chips to record video images. In cheaper surveillance cameras CMOS is normally used. CCD surveillance cameras produce better quality video. CCD camera formats are measured in inches, and the larger the format the brighter the images produced. A CCD format of 1/4″ or 1/3″ is good enough for most situations.
The number of TV Lines (TVL) is how the resolution of a surveillance camera is normally specified. This determines how detailed the video picture quality is. Cameras today typically produce a video resolution between 350-400 TVL. 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.
Black and white surveillance cameras are better in poor lighting conditions than color cameras. Lux is the unit of measurement used to indicate a camera’s sensitivity to light. A camera must have a light sensitivity of 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. Most home security surveillance systems have cameras with fixed focal length lenses, which means that the cameras do not have a zoom in/out facility. 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. In complete darkness, the range that these cameras can see varies, and is normally somewhere between 10 to 50 feet. Home security surveillance systems that have surveillance cameras with a PTZ (pan, tilt and zoom) facility are normally more expensive. 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 surveillance cameras are more expensive, are quite small, and are normally hidden within household objects. Dome housings are mounted on ceilings, and are commonly used with cameras that have a PTZ facility. Protective weatherproof security camera housings are used with outdoor surveillance cameras that need to be protected from the elements.
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. The first advantage is that you can immediately go to a specific point in a recording without having to fast-forward or rewind a tape. Secondly, you can playback an earlier part of any camera recording whilst that camera is still recording.
Built-in motion detection is included in some home security surveillance systems. The system can be set to only start recording video when motion is detected. 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. Special software must be installed on the PC, and a PC board must be installed inside the PC case. PC based DVR systems are generally slower, and a lot more unstable when compared against any freestanding DVR system.
The recording on a 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. The is is the quality of the video recordings in terms of resolution (TV Lines), and the video frame rate (video smoothness). The second consideration is the number of cameras that you will need for your home security surveillance system. Entry-level systems come with 4 cameras. The size of the hard drive you need for the DVR system is your third consideration. 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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