CCTV systems are becoming more and more commonplace, with both public entities and private societies and individuals increasingly opting for them. Having recently installed a CCTV system in our apartment, I thought of sharing some useful pointers that will help the readers make a more informed choice.
First and foremost, it is essential to know the basic components of a typical CCTV system, namely the following:
- Cameras (can be analog, digital/HD or IP)
- Cabling, to carry video from the cameras to the DVR
- Digital Video Recorder (DVR) or Network Video Recorder (NVR), to process and record the video feeds
- Hard Disk Drive (HDD), to store the captured video feeds
- Power Supply module, to power the cameras (optional)
Here are some of the key points to consider when purchasing and installing a CCTV system for your apartment:
1. Choosing the right equipment
- CCTV cameras are of 3 types:
- Analog cameras – They record video in analog format. Their resolution is measured in TVL (Television Lines), such as 600 TVL or 720 TVL (960H) (see this link to know the relationship between TVLs and pixels).
- Digital/HD cameras – They record video in HD resolution, such as 1.3 MP or 2 MP, but transmit it in analog format over coaxial cables. Various encoding formats are supported for sending the video to the DVR, such as HD-CVI, HD-TVI, HD-SDI, etc. with HD-SDI being the best.
- IP (Internet Protocol) cameras – They also record video in HD resolution, but use Cat 5/5E cabling to transmit the video in digital format. Due to this, IP cameras can support much higher resolutions than HD cameras.
- Analog and digital/HD cameras are recommended for homes, apartments and smaller stores. IP cameras are more suitable for offices and large stores as they usually have a pre-existing LAN infrastructure that can be leveraged for CCTVs as well.
- Quality wise, digital/HD and IP cameras are far superior to analog cameras. Digital/HD cameras have an added advantage in that they use the same coaxial cables as those used by analog cameras, which saves on costs if upgrading from an existing analog CCTV system. As far as possible, go for HD or IP cameras with minimum 1.3 MP or 2 MP resolution.
- Analog cameras are obsolete, and even the highest resolution models (720 TVL/960H) cannot compete with HD or IP cameras. If you still decide to opt for analog cameras, ensure that the resolution is 600 TVL or more.
- Regardless of technology (analog, HD or IP), all CCTV cameras come in two form factors:
- Bullet cameras – Designed primarily for outdoor use.
- Dome cameras – Recommended for indoor use.
- Most cameras today are Infra-Red (IR) enabled, meaning they can record in the dark. Ensure that the camera you buy has this capability.
- The DVR/NVR must be chosen depending on the camera type:
- Analog DVR – Meant for analog cameras. For best results, the DVR must support the full resolution (TVL) of the camera.
- HD DVR – Meant for digital/HD cameras. Again, ensure the DVR supports the video resolution and format used by the HD camera (HD-CVI, HD-TVI, HD-SDI, etc).
- NVR – Meant exclusively for use with IP cameras.
- DVRs/NVRs typically come with 4, 8 or 16 ports/channels. Each port can connect to one camera. Always retain a few spare ports for future additions, so that you don’t have to replace the DVR or purchase a new one just to add an extra camera in future.
- Buy a HDD that has adequate capacity to store at least 1-2 weeks of video data. A 1 TB capacity disk is adequate for 8-10 cameras, but a 2 TB disk can also be used.
- Most importantly, buy a surveillance grade HDD designed for continuous operation and not a regular HDD designed for PCs as it will wear out faster.
- For analog cameras, coaxial cables are the norm, but Cat 5/5E cables with Baluns can be used in certain cases. The specific cable to be used depends on the distance between the DVR and camera:
- For cable lengths below 250 metres, a RG59 coaxial cable (left in below image) is adequate.
- For cable lengths over 250 metres, a RG6 coaxial cable (middle in below image) should be used as it has less signal degradation and is less susceptible to external interference.
- For cable lengths over 500 metres, a RG11 coaxial cable (right in below image) must be used as it gives even better signal integrity than RG6.
- If power is drawn from a common power supply, Siamese coaxial cables must be used (RG59+2 or RG6+2). These have two wires for carrying power, in addition to the coaxial cable.
- For digital/HD cameras too, the same coaxial cables can be used (subject to the above distance restrictions). This is a signficant advantage of HD cameras, especially if upgrading from an existing analog CCTV system.
- For IP cameras, only Cat 5/5E (Ethernet) cables are supported, as these cameras transmit video in Ethernet format to the NVR.
NOTE: For analog and digital/HD cameras (except HD-SDI), Cat 5/5E cables with Baluns can be used if there are multiple cables running together and cable lengths are long. This scheme provides comparable video quality to RG6/RG11 while cutting cable costs, since a single Cat 5/5E cable carries 4 camera feeds and can replace 4 coaxial cables. But do ensure to use a good quality Balun to avoid deterioration in video quality.
2. General installation tips
a) Positioning of cameras
- Basic CCTV cameras have a low resolution and do not give good visibility at long distance. So try to install cameras at locations where you can capture the faces of people coming and going at short range. The ideal location is in front of all the lifts and staircases on the ground floor or basement, as all visitors and residents inevitably pass from here on their way in and out.
- You can also put additional cameras to cover the main entrances to the apartment, such as the front gate. This way, you can also keep a tab on the security staff and verify if they are doing their job properly. You can also check what stuff people carry on the way in and out.
- Most importantly, don’t try to focus cameras on the perimeter walls as that is useless unless someone is actively monitoring the camera feed in real-time. Moreover, it will not yield any actionable data in case of theft; at best you will see blurry images of someone entering and exiting over the walls.
- As far as possible, try to install the cameras well above body height so that they are not easily accessible by hand.
b) Location of DVR/NVR
- It is very important to ensure that the DVR is kept in a safe place. You don’t want the DVR itself to be stolen during a theft!
- Keeping safety in mind, do also try to choose a central place for installing the DVR with respect to the planned placement of cameras, as this will reduce overall length (and cost) of cabling.
- If IP cameras are being used, location becomes less important, as a single Ethernet cable is adequate to carry the video feeds from all cameras to the NVR via an Ethernet switch (similar to how multiple PCs connect to a server over a LAN).
c) Power supply and backup
- Ensure that the DVR/NVR has a backup power source (such as a UPS) to remain online during a power cut.
- Analog and digital/HD cameras can be powered from a local power outlet or from a common power supply module kept near the DVR. Using a common power supply will increase cabling costs (as Siamese coaxial cables will have to be used instead of plain coaxial cables), but the advantage is that a single power backup and surge protection module can be used to protect all the cameras. If powering locally, ensure that the local power point has a backup power source.
- IP cameras can be powered either from a local power outlet or via PoE (Power over Ethernet).
3. Maintenance tips
- Ensure that the cameras are cleaned once a month, or else over time cobwebs can form on them and the cobweb movements in the wind can keep the cameras recording even if no other activity is taking place. This will prove to be a pain if you have to review the footage later. Ordinarily, when there is no activity taking place, the DVR doesn’t record the camera feed which makes it easier and faster to review the footage later.
- If coaxial cables are used, you will probably need to replace them after about 5-8 years.
- HDD will also need replacement after a few years due to wear and tear of constant operation.
- CCTV TVL and their pixel equivalent: http://hblstore.co.uk/cctv-tvl-pixel-resolution-explained
- HD analog CCTV formats compared: http://www.supercircuits.com/lp/compare-hd-analog-video-formats