The camera is probably the most well-known component of a video system. You can choose from three types.
- Network TV cameras, also known as IP cameras (IP stands for Internet protocol), use the computer’s network and internet to send and receive footage to monitors and video recorders.
- Cloud TV cameras, pretty similar to IP cameras, also use the computer’s network and internet to send and receive footage, but this time to the cloud. Most of them also have recording capabilities and use the cloud only for remote management, viewing, and backup storage.
- Analog TV cameras: while are less and less used today, some legacy systems still use them. However, they’re likely to be incompatible with more modern technologies, and we won’t treat them with this material.
From the construction point of view, TV cameras come in various configurations.
Bullet TV cameras: The name comes from bullet-shaped, and they have a compact construction: camera, lens, and housing to provide extra lens protection. These cameras can easily be mounted with a mounting bracket and come fitted with either fixed or varifocal lenses, depending on the requirements of their intended application. As they are pretty visible, they can deter some threats.
Dome TV cameras: Dome cameras look like upside-down half-spheres, and they are the most common cameras used in security and surveillance. The shape of the camera and tinted glass keep the lens orientation hidden, making it difficult for onlookers to tell which way the camera is facing, thus deterring criminals by creating an air of uncertainty. They are pretty easy to install, and most of them are provided with IR LEDs for night vision.
Box TV cameras or C-mount: They have a box shape, come with detachable lenses, and need an extra bulky housing when installed outdoors, where they are often used. The main advantage of these cameras is that they allow for lens changes to fit specific applications. Whereas standard bullet cameras can mostly cover distances of 10-15 m, box TV cameras are excellent for long-range outdoor applications and deterrence.
Pan-tilt-zoom: PTZ – have a built-in mechanism that allows the camera to be moved left or right (panning), up and down (tilting), and even allows the lens to be zoomed closer or farther to precisely point them at specific objects in the camera’s field of vision. These cameras are used in situations where a live guard is operating the security system. They can cover distances up to 20 -250 m with a high-quality resolution. Some of them are also provided with powerful IR LEDs for night vision.
Video recording is the process of storing video and associating it with a database or directory of each video file that is stored.
There are 4 fundamental options to record video footage in security systems:
- Network Video Recorders,
- TV cameras
- Video Management Systems,
- Network Video Recorders
A Network Video Recorder, in short, enables you to record, store, and replay videos on demand from all connected feeds, and it is a critical component of any video security system.
While using off-the-shelf computers and/or standard hard drives as NVRs is possible, we do not recommend this approach. These machines are subject to one of the hardest regimes in a company, as they process, read, and write enormous quantities of video data 24/7.
High-performance NVRs usually support recording redundancy to protect video information and ensure the data is always accessible and safe from harm. The RAID method is the most common and least expensive method to provide file redundancy for recorded video. The most common RAID architectures used in surveillance storage are RAID 5 (1 redundant drive) and RAID 6 (2 redundant drives).
Another method to avoid losing data is to record on two recorders simultaneously, while backup storage means the video is first recorded on primary storage and then copied to a secondary/backup storage location. However, being pretty expensive, this method is uncommon in most surveillance systems.
For entry-level applications, NVRs have been developed as all-in-one solutions (an all-in-one hardware and software appliance). This simplifies the video surveillance system in a plug-and-play format and offers the lowest cost for most video surveillance applications.
2. TV Camera
Recording on a camera (microSD, SSD, Flash), normally eliminates the need for a separate recorder and simplifies, in a way, the installation, but probably increases the cost per byte in certain configurations. Because of the cost and complexity, camera-based recording is not common in on-premises systems but is more common in cloud solutions.
Because VMSes are software applications, they can be installed on commercial off-the-shelf computers, which offers some flexibility. However, this flexibility also requires specialized knowledge to design for specific system requirements, and it is not recommended in all situations.
Many VMSes are modular, and they can be configured either as an all-in-one system (fundamentally the same as an NVR) or with separate centralized system management servers and VMS recorder servers.
Cloud recording is the most trendy option today, and it is effectively the inverse of NVR recording.
While an on-premise recording system has physical limitations and is subject to continuous degradation and obsolescence, the cloud system provides continuous improvement, unlimited expansion, flexibility, and redundancy, regardless of the system size, small or large.
However, cloud computing requires consistent Internet upload bandwidth, although, today, there are some video cloud solutions on the market that provide smart bandwidth management. Also, there are Hybrid solutions that support storing video on-premise devices and backups in the cloud, which reduces the need for large bandwidth.
Apparently, cloud recording typically requires an expensive recurring subscription, which „traditional methods” do not. However, using cloud recording eliminates or decreases the need for on-premise hardware (except the cameras) and expensive local IT support and Support Plans for VMSes and servers.
A Video Management System (VMS) is a software-based platform that is used to manage and control video surveillance cameras, recording devices, and other components of the video system.
Usually, when buying VMS for larger installation there will be a base server software, to which are added the corresponding licenses for each TV camera installed in the video system. However, the VMS structure depends on the size of the video system and the VMS provider.
In large-scale surveillance systems, VMSs require separate hardware (physical servers, virtual machines) and an operating system to function. These servers are connected, through the network, to field Network Video Recorders, TV cameras, and remote workstation clients.
For smaller systems, the NVRs are preloaded and bundle the video management software in their appliances with an operating system, so there is no need for extra hardware, except the TV cameras.
Functions of a VMS :
- System Management: One of the main functions of a VMS is the management of users, schedules, and hardware (servers, client workstations, recorders, TV cameras, settings, health monitoring, firmware, rules, etc)
- Live Video Monitoring: VMS systems allow security personnel to view live video feeds from surveillance cameras in real time, either on-site or remotely.
- Video Recording and Storage: VMS systems allow for video recording from multiple cameras, and the recorded video is typically stored on a Network Video Recorder.
- Searching Video: The VMS system provides the ability to search and retrieve recorded videos which is a critical feature for a VMS. Search for a person/vehicle, event, or left-behind object is important for most users, and VMSes usually provide different search types, depending on what information is known. Time, motion, thumbnail, and bookmark searches are the most common types.
- Video Analytics: Modern and more powerful VMSes systems can incorporate video analytics and AI to automatically detect and alert security personnel of suspicious or abnormal behavior and provide intelligent search capabilities.
- Exporting Video: When crimes, accidents, or problems occur, exporting video from one’s video surveillance system is critical to proving incidents.
- Watermarking / Encryption To be sure that exported video is not tampered with, watermarking and encryption can be added to the video to ensure it has not been edited or tampered with.
- Integration with Other Security Systems: VMS systems can be integrated with other security systems such as access control and alarm systems, allowing for a unified security management platform.
Overall, a VMS provides a comprehensive solution for video surveillance and security management, allowing organizations to effectively monitor their facilities, assets, and people in real-time.
At the „monitoring workstation” (computers), operators use software-client monitors to view and review camera feeds. They provide delivery points for security recorders, taking some of the burden off the NVR, and enabling better recording and video management. Usually, workstations can be easily added and removed at any time based on the needs change.
Today, real-time video streaming apps allow operators to take the monitoring station on the go, watch live video feeds, review historical footage, and store video data for future use. Many modern systems make apps for mobile devices and laptop computers to provide extra flexibility.
The power supply is another critical part of a video system. Modern TV cameras accept power-over-Ethernet (PoE), a method that enables to transfer of power and data from a PoE-enabled Switch to the camera, using the same CAT cable.
This eliminates the need for an extra Power Supply for a TV camera, offers installation flexibility, and reduces costs with equipment and installing services that could be quite consistent in systems with many TV cameras. However a proper UPS is needed.