Written by Motion Tracking PTZ Camera with Built-In Recorder and Night Vision
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 surveillance cameras and the video recording device are the two main parts of any home security surveillance system.
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. 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.
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. 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.
Black and white surveillance cameras are better in poor lighting conditions than color cameras. 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. The cameras in most home security surveillance systems have lenses with a fixed focal length – these cameras do not have a facility to zoom in and out. 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. More expensive home security surveillance systems have cameras with a pan, tilt and zoom (PTZ) facility. Pan, tilt and zoom (PTZ) cameras allow someone to remotely pan a camera left and right, up or down, and to zoom in and out.
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. Dome housings are mounted on ceilings, and are commonly used with cameras that have a PTZ facility. Weatherproof security camera casings 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.
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. A standalone DVR system is normally quicker, and more stable when compared against a PC based system.
The recording on a standalone 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 resolution of video recordings in TV Lines, as well the video frame rate (smoothness) of the recordings. 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.
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