Video surveillance systems have come a long way. The early analog systems were very inefficient and required massive amounts of storage space. Today’s new digital video surveillance systems are more versatile and efficient and have superior image quality.
Characteristics of an Analog Video Surveillance System
What is an Analog video surveillance system? Simply put, an analog video surveillance system collects video and transmits it over a traditional base band format to a Digital video recorder of some kind or DVR. Once it reaches the DVR it is converted to a digital format so it can be compressed and stored on hard drives.
Analog video surveillance systems have been around since the first CCTV system was installed at a test stand in Peenemünde, Germany in 1942, for observing the launch of V-2 rockets. At the time, it was an innovative, state of the art system. However, they had no way to record the footage. Thus creating the need for the first live monitored video surveillance system.
Analog surveillance systems require that each camera has its own dedicated coaxial cable and usually must be expanded by either 4 or 16 cameras at a time. The installation of an analog system requires massive amounts of coaxial cables for video and may require specialized cables for audio capabilities as well.
The amount of cables involved in the installation and maintenance of an analog system can boggle the mind. Each camera not only needs its own dedicated coaxial cable for video and possibly another cable for audio, they each need their own power supply. The need for power to each camera is solved with a digital system since digital surveillance system cameras can use POE which is a way to get their power from the Ethernet cable.
Each analog camera on a video surveillance network must be connected directly to the digital video recording device. This limits the number of cameras you can add to the number of ports you have on your recording device. With a digital video surveillance system, there are multiple ways in which you can expand your network using switches and other equipment.
One major drawback of analog surveillance cameras is that they have extremely low resolution which provide grainy, blurry, and unclear images. The maximum resolution available in an analog camera is equivalent to approximately .4 megapixels. In comparison, today’s most advanced digital video surveillance cameras are available in up to 11 megapixels.
Low resolution is not the only cause of analog video surveillance camera’s production of such blurry images. Analog cameras use a process called interlacing. This interlacing is what creates the jagged video and blurry images. The way interlacing works is by dividing the images.
The Interlacing process involves dividing images into two sets of lines, odd and even. These lines are then refreshed alternately. This alternate refreshing is what causes moving objects to appear jagged and or blurry and creates distortion in the video.
The reason it is so blurry is that only half of the lines are recording at any one time while the other half wait to be refreshed. Once both images are received by the DVR and put back together, the images have moved slightly, and therefore create a blurry image.
Analog cameras also do not have the same digital zooming capabilities as digital video surveillance cameras do. The grainy pictures produced by an analog camera only become grainier and blurrier when you zoom in. The poor resolution and grainy picture make it difficult or even impossible to identify people and see what exactly is happening at any time.
Another characteristic of analog video surveillance cameras is their narrow field of view. With traditional analog cameras you had to install several cameras in order to watch a large area. A digital surveillance camera can cover three to four times as much area than an analog camera can.
Possibly one of the largest drawbacks to an analog video surveillance system is the fact that they do not work well as a wireless system. Analog signals must follow several government guidelines and are prohibited from being encrypted and are extremely susceptible to interference. In addition to interference, your system will be vulnerable to hackers. Florescent lighting can also be very problematic for wireless analog networks.
Benefits of A Digital Video Surveillance System
There are many benefits of a digital video surveillance system. Digital surveillance systems are superior to analog in their ease of installation, their ease of use, their superior image quality, their data requisition and transmission processes, and many other ways.
The main difference between an analog and a digital video surveillance system is the way they collect and transmit the video signal. Analog systems convert the information into a digital format after it reaches the recording device. With a digital video surveillance system, the information is gathered in a digital format to begin with. Thereby eliminating the need to convert and compress the information at a later time.
Collecting the information digitally from the start makes the whole process much more efficient. Digital information can be transmitted more quickly than an analog signal due to the fact that the information is compressed prior to its transmission. Besides being faster, digital systems are superior because with a digital signal, there is no degradation of the image.
Since the video is collected digitally straight from the camera, there is more flexibility as to how and where you can record the video. In most cases, the DVR is replaced with an NVR (network video recorder), which can be simply software since the information does not need to be converted to a digital format.
As I mentioned earlier, digital video surveillance cameras have much higher image quality than their analog counter-parts. The most sophisticated analog cameras on the market today have a maximum of .4 megapixels. That is less than half of a megapixel. Even the cheapest digital cameras available today far exceed this in megapixels alone.
Sophisticated digital video surveillance systems have several capabilities other than transmitting video images. Today’s digital systems have the ability to control more than video. Apps can be downloaded to allow for remote access, access control systems, visitor management systems, and building management.
With remote access capabilities, it is far easier for a live video monitoring company such as Centralized Vision to monitor your property. With the right applications your video feed can be accessed anywhere with an internet connection which alleviates the need to have on-site monitors.
Access control systems allow you to remotely monitor and facilitate entry of guests to your facility. In addition to monitoring guests, you can set up alerts to inform you in the case of a door being left unlocked or propped open. With an analog system this would not be as easy to facilitate.
With a digital surveillance system, you can track your guests and visitors while they are on the property. In the event that a visitor is allowed only in certain areas of the building, you have the ability to control their flow. You can lock and unlock doors as needed to let them move freely about in authorized areas. Thus not leaving any access points open, unlocked or vulnerable to unauthorized access.
In addition to digital video surveillance systems having superior image quality and sophisticated app capabilities, another advantage is the ease of use when installing or adding to the system. When installing the system, it requires much less wiring than a traditional analog system.
Remember, an analog system requires separate coaxial cables, audio cables, and power cables. That is not necessary with the POE (Power over Ethernet) option available with a digital system. The cameras can get their power directly from the Ethernet cables.
A digital video surveillance system is easier to expand than a traditional analog system as well. With an analog system, you are required to expand your network in multiples of 4, 8, or 16. That is not the case with a digital network. With a digital video system, you can add a camera any time and almost anywhere that you want.
With the use of switches to connect your digital cameras to each other without wires. You can add many more cameras to a network than you can with an analog network. Digital cameras can even be installed without wires which makes it even easier. This gives you the ability to place your cameras almost anywhere.
Digital video surveillance systems are superior to analog systems in their ability to transmit wirelessly without interference and distortion. With a traditional analog system, there are several federal regulations that must be followed when transmitting wirelessly. The most problematic is the fact that you are not able to encrypt or protect the information.
With a digital system, there are not the same government regulations to abide by, and therefore your information can be transmitted with encryption and without the same distortion. You are able transmit your information quickly, safely, and with high quality.
Digital video surveillance systems have many advantages over analog systems. They are easier to use with far superior image quality and ease of installation. They are more sophisticated, have a multitude of capabilities, can easily grow with your needs, and are remotely accessible from anywhere. If you have any questions about digital video surveillance systems or how we can help protect what matters most to you, please contact us.