Analog vs Digital: Pros and Cons of DVRs in Security Systems
Simply drilling a few holes and installing a security camera is not the whole package. You need somewhere to store your camera footage. Most system installers will use the term “recorder”, you’ve probably heard it thrown around.
In terms of dedicated physical storage for your camera footage, there are two types of recorders currently in use. NVRs, and DVRs. This article will explain what a DVR is, how it works, and explore the pros and cons of using it.
How DVRs (Digital Video Recorders) work
A DVR is a Digital Video Recorder. They are being phased out of most security system applications nowadays, seeing their spotlight in the analogue camera era.
At a high level, DVRs work by encoding and compressing video data from cameras onto a hard drive. Which can then be accessed and retrieved as needed – you can record and store footage for later review, or to monitor your cameras in real-time.
In a DVR system, coaxial cables are used to connect analogue cameras to the DVR. The coaxial cable also provides power to the camera, eliminating the need for a separate power source. Coaxial cables are a type of electrical cable consisting of a central conductor, which is surrounded by layers of insulation and shielding to protect from signal interference.
The cables carry the raw analogue data straight to the DVR, which then converts it into digital video format and writes it to a hard drive for storage.
Alternatives to DVRs for video recording
NVRs were mentioned previously, but there are a couple of other popular video storage methods used with CCTV security systems.
NVR (Network Video Recorder)
NVRs are recorders designed to work with IP cameras, which are cameras that connect to a network using cables or wirelessly. NVRs are connected to the network and receive video streams from the cameras, which are then recorded onto a hard drive.
The main difference between an NVR and a DVR is the type of camera they work with. DVRs work with analogue cameras that use coaxial cables. An NVR works with IP cameras that connect to the network using ethernet cables.
Cloud storage is a method of storing video footage from security cameras in remote servers over the internet, instead of on a physical hard drive. The cameras send the video streams to the cloud service provider, which stores the footage and allows users to access it through a web portal or specialized software.
Unlike DVRs and NVRs, cloud-based recording eliminates the need for on-premises hardware and allows for remote access to footage from anywhere with an internet connection. However, it also requires a stable and reliable internet connection and may be subject to ongoing subscription fees.
MicroSD Card Recording
A lesser used type of recording, MicroSD card recording is a method of storing video footage from security cameras directly onto a microSD card, which is inserted into the camera itself. This eliminates the need for a separate recorder like a DVR or NVR. It also allows for a compact and discreet installation.
However, microSD cards have limited storage capacity and may need to be replaced frequently, especially for cameras that record frequently or for long periods of time. Additionally, footage can only be accessed by physically removing the microSD card from the camera.
Advantages of using DVRs in your camera system
Cost-effective installation and operation
DVR systems are cost-effective to install and operate, especially when compared to other security systems that use newer technology. DVRs are based on analogue cameras which were brought into operation over half a century ago, making them relatively basic and inexpensive. Overall, DVR systems require less maintenance and are easier to repair, which helps to minimize ongoing operational costs.
Ease of set up and use
Setting up and using a DVR system is relatively easy and straightforward. Since they’re designed for the sole purpose of encoding analogue video footage and recording it to a hard drive, there aren’t any network settings to fiddle with.
No cybersecurity threats
DVR systems are less susceptible to cyber threats than other types of security camera systems that rely on internet connectivity. Because DVRs do not require an internet connection to function, they are not vulnerable to hacking, data breaches, or other forms of cybercrime.
This added security measure makes DVRs a popular choice for installations that require high levels of privacy and security, such as government facilities or financial institutions.
Mix and match different security cameras
One of the key advantages of DVR systems is their ability to support a variety of security cameras from different manufacturers. Meaning you can mix and match cameras based on your needs and budget, without worrying about compatibility issues. The flexibility to choose basically any analogue cameras mean you have huge versatility and can overhaul an existing system rather easily.
Limitations of using DVRs
Coaxial cable degrades signal over distance
Video footage transmitted over coaxial cables can degrade over distance due to signal loss, resulting in poor image quality and potential loss of data. This degradation occurs because the signal experiences resistance as it travels along the length of the cable. This resistance results in a loss of signal strength, which can cause video distortion and signal dropouts.
The practical maximum cable range for coaxial cable is approximately 90 meters. Beyond this the signal may be too weak to transmit usable video footage. To overcome this limitation, signal boosters and amplifiers are used to maintain signal strength over longer distances. This is generally not practical in smaller systems and also cost prohibitive.
Coaxial cable size
Coaxial cables are known for being large and bulky. You may find this problematic because the cables can be difficult to conceal and may require additional hardware, such as connectors and adapters, to be installed properly.
This also means they are a difficulty during installation, particularly when running them through walls or other tight spaces. Due to their thickness, it is harder to make them bend in sharp corners, creating further hurdles.
Lower audio and video quality
Generally coax cables carry lower video quality than modern network cables. Even with modern advances in coax technology, using HD over Coax (HDoC), the maximum resolution you can transmit is 1080p. As security cameras get larger and larger image resolutions, this is an existential hurdle in analogue systems using DVRs.
Conclusion: Using Digital Video Recorders in your Camera Security System
In conclusion, a DVR security system can be a cost-effective and easy-to-use option for surveillance and security purposes. It allows for mix and match of different security cameras and eliminates the risk of cybersecurity threats.
However, the use of coaxial cables can limit the signal quality and distance, while the large size of the cables can be a challenge during installation. Additionally, the audio and video quality may be lower than other options such as NVR or cloud-based recording.
Ultimately, as we see the shift towards huge video resolution formats such as 8MP or even 12MP, and the rise of faster and faster internet connections, DVRs are being phased out in favour of NVRs or cloud storage.