Connection
-LAN. The LAN (Ethernet) interface was originally intended for building wired computer networks. Cameras with this connector, usually, also work as network devices. The advantage of this option over the Wi-Fi described below can be called a higher actual bandwidth, over
BNC — the ability to connect without additional equipment, directly to a standard network router used for a regular computer network. Of the shortcomings, one can only note the need to pull the wire, but this point is common to all wired connection options. For the rest of the features, LAN is the most convenient, thanks to which it has become widely used in modern security cameras.
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Wi-Fi. The 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 lack of wires, however, with an abundance of other wireless devices connected to the router, the channel bandwidth and image quality can noticeably deteriorate. Note that recently it is also possible to use this connection in the Direct mode — for direct connection of the camera with 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 commonly used for analogue video signal transmission. Refers to professional video interfaces, special equipment is required to work with such a camera. However, by themselves cameras with connectors of this type, usually, belong to the lower price range. This is due to limited connectivity via BNC — only a video signal can be transmitted through it, which limits the functionality of such cameras compared to models that work via LAN or Wi-Fi (see above).
— 3G / 4G. Internet connection via 3G / 4G mobile networks; usually, for this you need to install a SIM card from a mobile operator in the camera. The speed of such networks allows, among other things, to broadcast video in a fairly high resolution. So such a connection (of course, with coverage) is well suited not only as a fallback in case of interruptions to the Internet, but also as the main communication channel if there is no fixed Internet connection at all. A typical example of the second situation is the observation of a country house located "far from civilization", but in the zone of reliable mobile communication reception. Moreover, in both cases, you can contact the camera via the Internet from anywhere in the world. 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.
