Connection
—
LAN. The LAN (Ethernet) interface was originally designed to build wired computer networks. Cameras with such a connector, as a rule, also work as network devices. The advantage of this option over the Wi-Fi described below is a higher actual throughput, over
BNC — the ability to connect without additional equipment, directly to a standard network router used for a regular computer network. Of the disadvantages, one can note only the need to pull a wire, but this point is common to all wired connection options. In terms of other features, LAN is the most convenient, due to which it has become widespread in modern surveillance cameras.
—
Wi-Fi. Wi-Fi connection was originally a wireless analogue of the LAN described above and was used to connect to computer networks. When working in such networks, this connection is similar to LAN in the sense that it allows the camera to work through a regular router (of course, supporting Wi-Fi). At the same time, Wi-Fi is more convenient due to the absence of wires, but with an abundance of other wireless devices connected to the router, the channel throughput and image quality can significantly deteriorate. Note that recently it has also been possible to use this connection in Direct mode - for direct connection of the camera to another device, for example, connecting the camera to a smartphone (see "Design and capabilities -
...P2P"). However, this option is less common.
— BNC. Abbreviation for Bayonet Neill Concelman. A bayonet-type connector, usually used to transmit an analog video signal. Refers to professional video interfaces; special equipment is required to work with such a camera. However, cameras with this type of connector are usually in the lower price range. This is due to the limited connectivity options via BNC — it can only transmit a video signal, which limits the functionality of such cameras compared to models that work via LAN or Wi-Fi (see above).
— Aviation port. It is a round multi-pin connector designed for reliable connection of cameras. Such ports provide a stable connection even in conditions of vibration and high humidity, due to which it is used in car video surveillance systems. Power, video signal and control (for example, for PTZ cameras) can be transmitted through one aviation port, which simplifies installation and reduces the number of required cables.
— 3G / 4G. Connecting to the Internet via 3G / 4G mobile networks; as a rule, this requires installing a SIM card from a mobile operator in the camera. The speed of such networks allows, among other things, to broadcast video in fairly high resolution. So such a connection (of course, if there is coverage) is well suited not only as a backup option in case of Internet outages, but also as the main communication channel if there is no fixed Internet connection at all. A typical example of the second situation is monitoring a country house located “far from civilization”, but in an area with reliable mobile phone reception. In both cases, you can contact the camera via the Internet from anywhere on the planet.Signal to noise ratio
The signal-to-noise ratio that the surveillance camera corresponds to.
This indicator describes the ratio of the level of the useful signal (the actual image produced by the camera to an external device) to the level of extraneous noise that inevitably arises during the operation of electronic circuits. Such noise appears in the image as characteristic noise (“snow”). The higher the signal-to-noise ratio, the less interference on the screen, the clearer and better the image is, and the smaller the volume of recorded video files. It is believed that visible noise practically disappears at a ratio of at least 45 dB. However, among modern cameras there are also higher rates.
Material
The main material used in the construction of the camera body.
— Plastic. Inexpensive and at the same time quite practical material. Plastic is light, quite strong (not as strong as metal, but still quite sufficient for most cases), chemically inert (and therefore not susceptible to corrosion and insensitive to moisture), and also has a relatively low thermal conductivity (which provides additional protection for extreme temperature fluctuations). Due to all this, this material is very popular in indoor chambers (see "Usage"). At the same time, it is somewhat less suitable for outdoor work.
— Metal. The main advantage of metal, in comparison with plastic, in the case of surveillance cameras is high strength and reliability. This allows you to use it even for street models that work in difficult conditions and must have a certain anti-vandal resistance (at least not immediately “give up” when trying to break or break). At the same time, such material is much more expensive, and therefore less common.
