Looking to choose a CCTV System for your home or office but not sure where to start. Well, you have come to the right place. Let us help you understand the range available and take you step by step as you make your decision.
Which Technology to Choose for your CCTV System
There are 3 CCTV Technologies that are available:
- HD Analogue
- Network IP
Analogue CCTV System
Invented in 1942, the analogue CCTV system has gone the way of the dinosaurs as the world pushes towards digital and IP networks. This traditional old technology uses coaxial cables to transmit the video signal from cameras to Digital Video Recorder.
Being analogue, its best possible resolution of 960P HD is 1280 x 960. For most legacy analogue cameras, they are at best D1 Resolution of 720 x 480. Compared to the IP cameras, the analogue images appeared grainy and lacking in detailed sharpness.
HD Analogue CCTV System
HD Analogue Cameras are HD Cameras that operate using coaxial cables. They were created to offer a transition path for customers who wants High Definition Image Resolution without running new network cables. Most HD Analogue cameras can support the different transmission formats that was created. These format are the TVI, CVI, AHD and the SDI. They are standards used to govern how high definition analogue videos are transmited over a coaxial cable.
TVI stands for “Transport Video Interface” that is popular and widely used. Hikvision cameras used this format. CVI stands for “Composite Video Interface” developed and adopted by Dahua. AHD stands for “Analog HD” is adopted by Korean image sensor manufactuers and popular in Korea and Japan. And SD stands for “Serial Digital Interface” which is the earliest but have since been discarded by many camera manufacturers as it is more expensive than the other technologies.
Many HD Analogue cameras can support the format of analogue, TVI, CVI and AHD. A simple toggle switch located at the camera allow the camera to work with different DVRs.
For legacy analogue systems, the first step to upgrading to HD involves changing the DVR to HD DVR. The HD DVR can receive analogue signals from existing cameras. And as the analogue camera fails, you can replace it with a suitable HD Analogue camera.
Network IP CCTV System
If you are installing a new system, we recommend choosing Network IP CCTV System. Going Digital is the way forward. And using network IP cameras provides the best value and also future proof for your investment. Being network based, it allows faster data transmission and greater image compression. And with Video Analytics and AI deep learning, network cameras are playing a big part in crime prevention and detection.
Even normal IP cameras are now equipped with biometric face recognition that is quickly integrating with door access. Video Analytics coupled with deep learning is enabling cameras to play the role of burglar alarm and even fire detection. The potential is limitless.
And camera manufactuers are investing time and money to make it better and more affordable. A 4MP camera is now a fraction of the 1MP camera when it was first introduced. And right now, the defecto resolution for many commercial project is 4MP. But in the near future, we would not be surprised that 8MP would become the standard as 4K monitors becomes affordable and hard disk move to more compact capacity.
But if you do not want to reinstall cables or do have the budget to change the entire system, you can consider upgrading the analogue to HD Analogue.
How many cameras do I need?
If you are planning to install the cameras for your place, it is good to perform a security risk audit and determine the critical areas.
Work out the number of cameras needed to cover the perimeter of your house. Cameras coverage are 90° so positioned them at corners to reduce blind spots. Typical houses would have 4 cameras on the exterior – front porch, back porch and sidewalks.
For the interior, common places would be the living room, dining room, kitchen and common corridor.
Dome or Bullet Cameras?
The specifications of dome and bullet cameras are similar. So technically, there is no difference between a dome or bullet camera. Their difference lies in the aesthetics and how and where the cameras would be mounted.
Dome are normally used for indoor ceiling mount. Bullet cameras are typically wall mounted and in most cases, mounted outdoor. With mounting brackets and accessories, you can mount a dome on a wall and a bullet on a ceilng as well.
Motorised or Wide Angle?
How wide the angle depends on the lenses used. Most cameras we used are fixed lens camera of 2.8mm. This gives you a coverage angle of 90°. We placed the cameras in the corner of a room so that it can cover the entire room, reducing the blind spots.
For long corridors or passageway, where possible, we may recommend wide angle 180° cameras. We can then view anyone walking or approaching from the left or right. And only for special application where you need to view a full room from a bird’s eye view, we would use a 360° fish eye camera. Some fisheye cameras comes with 3 lenses to build the 360° view.
Motorised cameras that allow zooming in or Pan and Tilt are available and used for larger commercial projects. These are typically used where there are manned security personnel who operate these cameras to zoom in to areas of interest.
How to Choose NVR?
Network Video Recorders comes in 4 channel, 8, 16, 32, 64 and even 132 channels. A 4-Channel NVR supports only 4 cameras and a 132-channel NVR can support up to 132 cameras.
No of Channels
In your selection, it is good to work in some buffer. So if your home requires only 4 cameras, it may be good to get a 8 channel rather than 4. This buffer gives you expandability. And in the future if you needed to add wifi cameras, they can be linked to your recorder, And for some homes where we installed our Akuvox Intercom, the cameras in the intercom door stations are ONVIF compatible and is compatible with our Hikvision NVR.
Number of Hard Disk Slots
For homes, selecting a NVR that support 1 hard disk slot is sufficient. But if your application is an office or an industrial building, you may want to consider having more hard disk slots. The Hikvision NVR range can support 1, 2, 4, 8 and 16 hard disk slots. And for some models, the HDD slots can be configured to suport RAID.
The number of hard disk slots depends on how many cameras you have, how long you want to keep the records, and do you need RAID.
For a typical home application of 4 cameras with 30 days recording, a 4TB hard disk is more than enough. Hence a single slot is sufficient. But for large offices or building that have 16 cameras or more and need 30 days, a 2 slot hard disk with 8TB each is more than adequate.
But if the application requires RAID, then we are looking at 4 slots, 8 or even 16 slots. A RAID array allows for redundancy. Meaning that if one hard disk is corrupted, data can be recovered and rebuilt from the data stored on the other hard disk. But note that for RAID to work properly, we will need to use Enterprise Grade Hard Disk.