A Guide to Home Security Surveillance Systems

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. 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.

Resolution of a surveillance camera is specified as the number of TV lines (TVL) produced by the camera. This determines how detailed the video picture quality is. The resolution typically produced by surveillance cameras is normally between 350TVL to 400TVL. The number of separate images that a surveillance camera can record per second is said to be the frame rate of the camera. 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. Lux is the unit of measurement used to indicate a camera’s sensitivity to light. The light sensitivity of a camera 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. Cameras with a motorized zoom are quite expensive, and allow you to remotely change the camera’s focal length.

3. Other Surveillance Camera Features

Some surveillance cameras include Infrared (IR) LEDs, which project an infrared light allowing you view video in complete darkness. The range that these camera’s can see in the dark vary, and is typically between 10 to 50 feet. Cameras with a pan, tilt and zoom (PTZ) facility are included with the more expensive home security surveillance systems. 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 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. A PC board must be installed inside the PC, and special software installed on the PC. 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. PC based systems generally do not perform as well, and are not as reliable as DVR 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. Four cameras are normally included with entry-level systems. 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.

 

For more information about home security and home safety, take a look at the Home Security Buff news feed at Feedage.com.

 Mail this post

Comments