More and more often we think about how to ensure the safety of our home or business. One of the most frequently chosen forms of security are cameras. Monitoring an important facility for us does not have to cost several thousand zlotys at once. In some cases, we will also be able to call one camera with a memory card a monitoring system. We can already have such a system for PLN 250. On the other hand, ip surveillance systems for 4 cameras with the most popular resolution of 5 mpx start at PLN 1,500.
In the following article, we will discuss the main parameters that we should consider when choosing cameras for monitoring:
- maximum number of cameras
- installation location
- camera resolution
- infrared illumination range
- compatibility with other cameras or recorders.
Maximum number of cameras
The first question we always ask our clients is: How many cameras would you like to have at this location in the future? Why is this the most important question? Because knowing the answer to them, we know whether we need to buy a recorder and if so, how many cameras it should support. Knowing the number of cameras, we can estimate what period we will be able to go back and review the recordings. Thanks to this, we know whether we should choose a 1TB or 4TB drive, or maybe 8TB. The above answers will allow us to know the cost of our kit. Then the expectations usually collide with the size of the budget.
Place and method of installation
Are cables already laid in the building where we want to install the monitoring system? If so what are they? Is each LAN (computer) cable suitable for connecting PoE cameras (a standard that allows power and image to be sent in one cable)? Unfortunately, not everyone. To install PoE cameras, a category 5e cable is enough, but it must be 100% copper. Non-copper cables conduct power less well and over 20-30 meters the camera may restart or not start at all. If there are no cables, we should try to lay them. Monitoring on a good cable installation will always be a better solution than wifi.
Sometimes, however, we have a building where there are no cables and it is not possible to lay them. In this case, you need to check whether the router we have generates a sufficient wifi signal in the place where we want to install it. We have written an article about this before and if you are interested, we invite you to read it WIFI Cameras. Insufficient wifi coverage may increase costs by having to purchase amplifying antennas, extenders or wifi amplifiers.
Another aspect is the mounting height and the distance of the camera from the monitored area. Why does it matter? The type of lens used in the camera is crucial. Customers often ask us to propose a good cheap camera that will allow you to identify an object from 40-50 m. Cheap cameras are the ones that are most often sold. 90% of customers are looking for cameras with a wide angle, and this is 109 degrees. Recognition of a face or license plate during the day from a 5 mpx camera in this case is a maximum of 15-20 m. With a 2 mpx camera it is 8-10 m. optical zoom adjustable manually or automatically. Five-times automatic zoom can increase the price of our camera up to 2 times.
Why is camera resolution so important in surveillance? There are several reasons. First of all, the higher the resolution of the camera, the sharper and clearer the image. But not only. With higher resolutions, we need to use a recorder with a more advanced processor to be able to handle the recording and playback of the material. The resolution of the cameras affects the choice of hard drive. With a higher image resolution, we need a faster internet connection so that the router can send us the image to the phone.
We should also mention the megapixel high resolution analog systems such as AHD / HD-CVI / HD-TVI. Hybrid recorders priced below PLN 1,000 usually record images from cameras at a speed below 10 fps. Below are examples of recording speeds from analog cameras on the recorder.
|5 Mpx||Max. 6 kl/s|
|4 Mpx||Max. 8 kl/s|
|3 Mpx||Max. 9 kl/s|
|2 Mpx||Max. 15 kl/s|
Infrared illumination range
Tutaj wydawałoby się że sprawa jest prosta. Producent podaje do ilu metrów doświetlają w nocy kamery. Parametry są podawane w metrach i najczęściej występują 20, 30, 40, 50, 60 czy w zawansowanych kamerach obrotowych mamy nawet powyżej 100 m. Musimy jednak wiedzieć, że podczerwień inaczej odbija się od betonu a inaczej od zieleni. Dużo lepiej doświetla się zawsze obszar porośnięty zielenią niż surowy betonowy. Pytanie również czy monitorowany obszar jest w jakiś sposób doświetlony światłem białym czy ulicznym. Jeśli takie występuje to powinno nam wystarczyć doświetlenie około 20m. Jeśli jest brak jakiegokolwiek oświetlenia należałoby się pokusić o wybór kamery z doświetleniem minimum 30 m aby monitorować obszar wokół kamery.
Compatibility with other cameras or recorders
When planning to build a monitoring system, we must remember that different manufacturers offer us different cameras. Monitoring is characterized by the fact that its components must be compatible with each other. Most sellers inform us that their product is ONVIF standard so it will be compatible with all other devices with this standard. Unfortunately, it's not that obvious. First, there are different versions of this standard 1.0, 2, 2.4. 18, 50. It also turns out that large manufacturers such as Hikvision or Dahua have their own unique ONVIF protocols. It also happens that two products that have the same ONVIF standard are completely or partially incompatible due to too much difference in the software. Partial incompatibility is, for example, no recording after motion detection or no PTZ camera control function. It is worth contacting the seller before buying and finding out exactly whether the components of the set are compatible.