One of the most frequently asked questions when carrying out a CCTV installation is What are the ideal cameras? What recorder do I need? What hard drive capacity is adequate? Are the Wifi cameras or wired?
We must consider what our needs are to know which material is the most suitable: What do we want to record? What level of detail in the image do we need? For how many days do I need to save the recording?
First, we will have to size our video surveillance installation since the infrastructure necessary to install 4 cameras is not the same as to install 60.
To resolve these doubts and select the appropriate material, we will analyze each element of the installation:
Analog or IP system?
A choice that usually raises many questions is which video surveillance system to purchase. There are 2 types of video surveillance installations:
IP video surveillance system:
- Advantage: System adapts to large installations.
- CCTV installation with UTP cable being able to send both the power of the cameras (POE) and the data. Wifi video surveillance cameras so it gives us the possibility of installing cameras without having to wire from the recorder to the location of the camera. It allows more advanced and professional video analysis of images. IP cameras work on their own without the need for a recorder, but if we do not have a recorder we will not be able to review images, it will only serve to make live viewing.
- Disadvantages: This video surveillance system is more expensive than an analog video surveillance system.
Analog video surveillance system:
- Advantage: Ideal for small and medium installations of up to 32 cameras. Cheaper cost of both cameras and recorders compared to the IP video surveillance system
- Disadvantages: More limited image analysis (It has the functions that are usually needed in the vast majority of installations: line crossing, area intrusion, motion detection ...). It does not accept advanced solutions such as thermal cameras, license plate recognition cameras, people counting cameras ...
As a general recommendation, analog video surveillance systems are valid and competitive in price for most residential video surveillance installations and small and medium businesses that seek to have a surveillance system to go to when there are thefts or mishaps that We want to review, the cable that is used for this type of video surveillance installations is the coaxial cable or RG59 which is not very flexible.
We must also take into account the IP video surveillance systems They are easier to install, either through UTP cable, very flexible cable or with WIFI cameras which greatly facilitate installation by not having to cable offering us the same benefits and image qualities, this point can be decisive in choosing your system video surveillance.
The recorder is the brain of the video surveillance installation, it is the device that allows us to store the recordings to later view them either physically where the recorder is located through a screen or remotely through the mobile APP or in your PC application.
When choosing a recorder we have to take into account how many cameras we need to put, since recorders generally accept 4, 8, 16, 24, 32, 64 ...
We will also have to look at the image quality that we want to record since the recorders accept a maximum resolution per camera, currently the standard is FullHD (1920 x 1080 pixels) but there are already 4K resolutions (8Mpx) in analog and 12Mpx systems in IP systems.
Finally, another point that we must take into account is the storage capacity of the recorder. How many hard disks does it accept? The hard disks that it accepts what maximum capacity can they have?
This element of the video surveillance installation determines how long the images recorded by the cameras will be kept for review.
First of all we have to take into account the Organic data protection law that determines: "The data will be canceled when they are no longer necessary or relevant for the purpose for which they were collected or recorded." Instruction 1/2006 also establishes a maximum term expressly states in article 6 that: "The data will be canceled within a maximum period of one month from its collection." Taking into account this law, it will usually be that the recording remains stored for the time indicated by law.
How much hard disk capacity do I need to keep recording my video surveillance cameras for 30 days?
For this there are Applications that based on certain technological and configuration criteria of the VCR give you an estimate of what hard drive capacity you need.
As a general rule and with a current installation we will need approximately 2TB of capacity for every 4 cameras (1920 x 1080 Resolution) to save the images for 30 days in continuous recording mode (24h a day recording).
Today hard drive manufacturers like Seagate or Western Digital They manufacture specific discs for video surveillance systems, these discs are specifically prepared to perform constant writing and provide us with much greater durability than a conventional hard drive.
In video surveillance there are three types of cameras mainly due to their type of housing:
- Video surveillance cameras dome type: They are the most common cameras. They are mainly designed for ceiling installation although it can also be installed on the wall being smaller and more compact than bullets and therefore more discreet, there are models suitable for video surveillance outdoors or indoors.
- Bullet cameras or tubular: Tubular cameras are designed for wall installation but are adaptable to ceilings if necessary thanks to their supports, just like dome video surveillance cameras, there are models suitable for interior and exterior.
- PTZ cameras (“Pan, Tilt and Zoom”): they are domed looking cameras but larger. They have a built-in motor that makes them have the possibility of rotation both in height and laterally and they have powerful lenses to zoom.
The most common are the bullet and dome since they are much cheaper than a PTZ and fulfill the functions required in a video surveillance system.
The choice depends on 2 factors:
- Outer shell: provides protection against the weather elements and against shocks. Usually cameras are certified against time (IP66 or IP67) and against vandalism / protection (IK09 standard , IK10), so we will have to take into account whether we want indoor or outdoor video surveillance to make a good choice.
- Lens: In this factor we will have to analyze the image quality we need, that is, the resolution, the lens aperture (The usual are 2.8mm, that is, large aperture and 3.6mm, less degrees of amplitude), special features such as WDR (Improvement images with backlights), improved night vision ...
We will have to choose those cameras that offer us some characteristics according to the needs of each installation.
Lastly, remember that in addition to a good selection of material, it is also essential to place the cameras at strategic points, as well as the protection of the video recorder which stores the images and their theft would mean the complete loss of the recorded images.