Dome Cameras

Dome cameras have a half-sphere clear see-through dome bubble and were an industry-leading form factor. It allowed installers to mount the cameras in all types of environments and move the internal ball-type CCTV camera into any angle. While these have been sold in millions, there have been in 2 inherent issues with Dome cameras.
1- If dome cameras were exposed to rainfall, the rain could often settle on the dome and directly in front of the lens, thereby making the view out of focus and ‘blind’ to some extent.
2 – With a clear bubble Dome, natural sunlight could often be reflected due to the nature of the curved clear dome and the distance to the camera lens. Through time, installers have learned to observe the sun travelling from East to West as well as mounting the Dome camera horizontally to minimise or eradicate the reflection issue.
Turret Cameras
Turret Cameras were introduced in the last 10 years and are a good alternative to using Dome bubble cameras. Turret cameras still have the manoeuvrability as a Dome bubble camera to achieve the same viewing angles required, but Turret cameras have a flat glass lens which does not suffer from light stream intrusion.

Bullet cameras, like Turret cameras, have a flat glass lens, but their form factor is that of a tube with a bracket on the end. These Bullet cameras were introduced as fixed cameras with zoom lenses but, over the years, have been made to offer fixed and varifocal lenses as well. Bullet cameras offering a fixed position and zooming capabilities are often a cheaper alternative to a PTZ camera, which is larger in size and mechanical hardware and has larger zoom lenses. While bullet cameras are more budget-friendly compared to PTZ cameras, there are distinct advantages and disadvantages to be considered.
Advantage – A bullet camera is a fixed-position camera, usually lower cost compared to a PTZ while still being able to zoom long distances.
Disadvantage – A bullet camera being a fixed position camera can only view wide-angle images straight in front of it or fully zoomed directly in front of it, whereas a PTZ is a moveable camera and can change its view when a client requires to change the CCTV view at times, with most PTZ also offering pre-programmed Tours to view as much of the available views possible.

PTZ or Pan Tilt & Zoom camera’s main advantage is that the camera can move to any point in its viewing range and either zoom out, partially or fully zoom in. The PTZ camera’s internal functions allow it to move if an ‘alarm trigger’ from another area/zone is pre-programmed. A PTZ camera can cover vast areas on the premises over and above several fixed cameras.
Coax Cabled CCTV Recorders
Having chosen your megapixel cameras, whether they are fixed lens, varifocal or zoom lens types, with low light capabilities for night time and which Megapixel quality, the CCTV video images need to be recorded onto a Digital Video recorder to keep the evidence for when video evidence needs to be found and archived for later use.
Since the early 2000s, CCTV recorders have become digital. By that, we mean that a recorder is recording CCTV footage onto a Hard disc drive. The first Digital Video Recorders (DVRs) recorded camera images from coax-cabled cameras and recorded images directly onto their hard drive rather than old-fashioned tape.
Early DVRs were marketed with new terminologies to promote their capabilities, and these were known as Simplex, Duplex or Triplex DVR, and while these terms are not often used any more, it is worth understanding them. There are DVRs in the market which are simplex or Duplex in operation, more likely at the budget end. So, be sure to ask for clarification if your chosen DVR is a Simplex, Duplex or Triplex capable machine.
Simplex DVR allowed you to record video but not playback/ watch recorded images or archive video at the same time. Simplex machine recordings had to be stopped to allow an end-user to playback video. Furthermore, you had to write down the time, date and camera number manually to stop playback to use the archiving functions. Simplex was or is simple and, therefore, an entry-level price CCTV DVR for a reason.
With further development, manufacturers brought out Duplex DVR, which offered both recording and video playback simultaneously. Duplex machines offered Archiving as a separate function and meant that you could not record or playback while archiving.
The last of the developed entries of DVR’s were the Triplex DVR’s which featured live playback, recording and archiving of Video images all at the same time. Triplex capability can be found in most DVRs today, but these terms are not often referred to any more. For that reason, it is worth checking the specifications or asking the Integrator or supplier which type of DVR has been offered.
DVRs for coax cabled cameras have improved year on year, bringing more features into them and more comprehensive evidence search functions. DVRs in the market today offer analytical features such as tripwires, zone intrusion, objects left or objects removed, face recognition, power over Coax and Megapixel resolutions to suit the specification of your camera, just to name a few.
A tripwire is marked in the DVR’s menu section with a sample video image of the camera in question. For example, the boundary (perimeter) or entrance, a coloured line denotes the tripwire and will record video on its hard drive as an ‘alarmed’ video footage when that boundary has been crossed. This tripwire can be manually drawn with a mouse and re-configured to suit the end-users’ requirement on the perimeter. These tripwires can also have additional functions, such as ignoring traffic from the left and recording traffic from the right.
If the client has a zone within that scene that is out of bounds and requires highly important video images to be recorded, then the Zone intrusion not only records video footage but also adds alarm output features, enabling security engineers to fit Sounders, visible alarm Beacons, etc. This function is very useful where Health and safety on the site requires a Zone to be out of bounds for personnel.
With the advent of Facial recognition development in Access Control Systems and Video analytics, ‘Face recognition’ was also introduced into DVR’s. It is worth noting that most DVR’s to do not recognise a face against a database to confirm the same person. Most DVR’s have algorithms to identify a head & face within the CCTV cameras view and storing that separately as ‘face recognition’.
Objects left or removed are self-explanatory by recording ‘alarmed video’ if an object has been highlighted when an object has been placed into the area or an object being removed. The DVR will take a reference picture in its menu settings and always compare the reference image against the actual scene.
Power over Coax is one of the latest technological advances brought out by manufacturers on their DVR’s. Usually a Camera is powered locally, requiring a mains power outlet to provide power for a camera power supply unit at the camera location. Power over coax provides the camera’s power over the same video cable from the DVR. This feature reduces the installation cost at the various camera locations due do not requiring local power installations. While this technology is relatively new, it is recommended for an end-user to seek Integrators feedback on the suitability of power over coax for their site. Often an Integrator will not use existing old coax as power over coax would not be guaranteed due to the existing coax age or degradation.
Most DVRs allow for simultaneous recording of different Coax technologies, meaning that existing TVI technology cameras, as well as CVI, AHD and even CVBS (original analogue), can all be connected to the same DVR.
DVRs have always been sold with specific ‘inputs. ’ Inputs are the physical camera connections into the DVR. 4, 8, and 16-camera input DVRs are the norm and for larger sites, 32 and 64-camera DVRs are also common. We would also recommend splitting the total number of cameras over several DVRs.
For example, if your site had 128 cameras, we would recommend 4x 32 Camera DVRs. Should the unfortunate happen and a DVR break down, your 3 remaining DVRs are still operational and recording. A DVR with 4, 6 or 8 Hard drives spread over 4x DVRs offers more storage capacity compared to using a 128 input DVR with 10 or max 16 Hard drives. So, spreading the risk and performance over several DVRs may seem over the top in hardware installed but offers less risk and more options for archiving.
Almost every DVR sold today has Network capabilities, enabling the video to be exported to other external Hard disc drives, sending live or playback images to mobile phone CCTV Apps, Tablet Apps or web browser/video management software.
Where end-users need to get clarity on is the DVR’s overall performance capabilities to suit their camera’s performance. If the client has 8MP (4K) CCTV cameras, then the DVR needs to be able to record the same 8MP onto its HDD.
Some DVRs are being advertised as 5MP,6MP and 8MP (4K) recorders, but be aware that some DVRs do not make it clear as to how many inputs can record these higher Megapixel cameras at the same time while having lower resolution cameras connected also. While DVRs are advertised as 4K DVRs, it may be that only 2 or 4 out of a total of 8 inputs of a DVR can record 8MP (4K) and may also have slower video speed (frames per second) to record for the 8MP cameras.
Advertising can be misleading, and some 4K (8MP) DVRs allow for the recording of the 8MP (4K) cameras, yet the DVR lets itself down by only outputting 2MP monitor resolutions. These DVR brands could argue that you can zoom into the recorded 8MP (4K)image, but if you have an 8MP camera, why would you not want to see the full 8MP on a full-screen playback?
Checking spec sheets for Megapixel recording and playback capabilities should be one of the important facts to check first and foremost.
At the same time, other DVR models with true 4K (8MP) Monitor output show the complete 8MP camera resolutions in full-screen mode. There are just as many true 8MP (4K) DVRs with 4K Monitor output to give the full
Mega Pixel and max recording resolution.
There are now just as many DVR versions as there are cameras, as the Far Eastern manufacturers can easily manufacture different performance versions for every budget.
Sure, there are many clients for whom the technical specifications, performance differences and limitations can be too much to see through to get a clear decision, but there is professional advice at hand.
A reputable Integrator will be able to advise on which megapixel resolutions are suitable for which areas of your premises, where ‘low light’ cameras would be recommended to suit dark areas or camera locations that do not have any ambient lighting in the scene.
The Integrator should also be recommending the correct DVR with the correct megapixel recording and playback capabilities as the client is considering.
Network Video Recorders
The IP CCTV industry has developed from a Virgin territory from the late ’90s and is now a first choice CCTV technology for many upgrades and, in most cases, for new projects. Like an IT computer network, the interconnected cabling structures of a computer network so IP CCTV flourished due to an existing network technology to transport CCTV video images.
Similar to Coax cameras, IP security cameras have been developed with the same basic features; however, being in a digital age, new uses in IP cameras have been developed. IP ANPR cameras are automatic number plate recognition cameras with built-in algorithms to calculate the shapes of lettering into recognisable number plates that are then transferred into a database for correlation. Facial recognition cameras, where the visual video image of a face is analysed using algorithms and correlated with databases for identification.
Network Video recorders, again, operate with similar features as their DVR coax-based counterparts, yet offer more IT functionality and possibilities such as video storage transfer to multiple hard disc locations, if needed.
Network video recorders are the go-to product, where a network exists between buildings, allowing the computer network connectivity to provide the transport between IP CCTV camera and Network video recorder.
PoE-enabled IP cameras can be powered by the Network video recorder (NVR) power supply and is referred to as PoE (Power over Ethernet) for both cameras and NVRs. IP CCTV has long since taken technologies from its IT Industry friends and further developed these IT functions into the IP CCTV world.
As with any IP-based technology, PoE has been developed further in providing ePoE technology that uses advanced modulation to transmit video, data, and power up to 800 Mbps to 10 Mbps on a single CAT5E cable between an IP camera and a PoE switch.
These improvements allow for greater escalation of CCTV IP cameras being deployed on-site, yet being powered by NVRs with ePoE or CCTV IP ePoE network switches, minimising the need for localised power distribution to localised cameras.
The overall benefit of IP Network video recorders over Coax DVRs is that these can communicate anywhere in the world, between and with each other, as well as other devices to give greater intelligence to suit their industry and video evidence.
Which system – Coax-based CCTV or IP-based CCTV- is best for my site?
If the client is looking to upgrade an existing CCTV system, then keeping to the same technology is often the most logical and economical. There are not many benefits in building an IP system on an existing coax-cabled system. Even with today’s market, where video transmission equipment varieties can transmit IP camera video over existing Coax cable and vice versa.
The upgrading costs are best applied to the same technologies to provide valuable additions rather than more expensive integration equipment add-ons to utilise two completely different technologies
Coax-based systems are ideal for small to large camera sites where coax cables can run to 500 metres between cameras and DVR. Even with multiple sites being installed with coax-based systems, a client can monitor various site DVRs or cameras from sites via the brand’s dedicated video management software or other 3rd party multi-site software packages.
Where Coax-based cameras are less attractive in applications is where camera intelligence is required or on-camera feature changes can be controlled.
Coax cable-based Megapixel image quality is just as good as IP video cameras with equivalent resolution.
IP CCTV cameras can vary vastly in their technical features, giving greater choice to clients’ operational or functional needs. IP cameras can be accessed anywhere in the world, and changes can be applied remotely, making maintenance/software upgrades easier and more cost-effective.
A few specialised IP camera manufacturers have built their video recorders into the camera, being controlled and monitored via a web browser or management software. This benefits end-users who only need a single camera and have the NVR built inside the IP camera.
Again, some of these special surveillance IP CCTV cameras are manufactured with Face recognition or ANPR functionality, offering further value with its features and onboard recording.
IP cameras and NVRs have a greater megapixel range, with manufacturers concentrating on IP-based megapixel growth. IP-based video technologies from broadcasting, machine vision, robotics, etc. bring opportunities to the IP CCTV / IP security camera markets, often sharing ‘open’ technologies to improve the future where IoT or the Internet of things are concerned.
Bringing in a CCTV-specialised Integrator provides the end-user with greater advice and choices of technologies and a large pool of specialised CCTV equipment options.
Making key decisions is vital for the business or residential homeowner as any CCTV security budget is likely to be spent to either secure, prevent accidents, keep health and safety procedures up to date or provide suitable evidence against theft or provide a deterrent against theft.
Understanding a little more as to what CCTV technologies are out there may well help the client in deciding whether to upgrade or start with a new system and get the best out of their spending budget.
A good Security Integrator will have experience in guiding the right CCTV technology to the client’s needs and the client’s requirements. Additionally, Integrators will be aware of the latest technology features from different brands, which would ultimately serve the end-user best.
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