Video channels
The number of video channels that the set's recorder is capable of simultaneously processing. In fact, this is the number of cameras that the device can simultaneously work with; it is technically possible to connect more cameras, but this will require additional equipment — such as quadrators.
The choice for this parameter depends on how extensive and extensive the observation system is planned to be built. At the same time, it should be noted that modern technologies allow combining several registrars into a system with a single control; therefore, for numerous cameras, it is sometimes easier to purchase several relatively modest kits than one multi-channel one.
Camera model
A model of dome cameras supplied as standard with a video surveillance kit. Knowing this data, you can find detailed information on the cameras and clarify their characteristics. In addition, by purchasing additional cameras of the same model, you don't have to worry about compatibility.
Martix type
Type of matrices used in complete dome cameras.
— CMOS. Also known as CMOS. Matrices of this type have good speed, small size, low power consumption and lower cost than CCD. On the other hand, the image quality of CMOS matrices is somewhat worse, and the noise is noticeably higher. However, these shortcomings can be corrected with the help of constructive tricks, and the technology itself is constantly being improved. Therefore, today CMOS matrices can be found both in inexpensive and in fairly advanced cameras; the actual quality of the sensor usually depends on the price category of the camera.
— CCD. Another well-known name is CCD. Compared to CMOS, such matrices are much more expensive and thicker, but they have lower noise levels and noticeably improve image quality. Of the practical disadvantages of CCD, it is worth noting that it is difficult to properly process point light sources; however, in many cameras, this moment is compensated to one degree or another by special technologies. Matrices of this type are typical for cameras of the middle and top levels.
— DIS. The main feature of DIS matrices is the presence of a built-in image processor in the sensor itself. This allows you to achieve good image quality with small dimensions and low cost of the cameras themselves (although they are still more expensive than CMOS).
Matrix size
The physical size of the sensor in the complete dome cameras is diagonally, in inches (fractions of an inch).
The larger the sensor, the less prone it is to noise, the better image quality it can provide, and the better it is suited to low light conditions. This is due to the fact that each individual pixel gets more light, because. on a large matrix and individual dots are larger. On the other hand, large matrices are more expensive.
Water resistance
The degree of protection of the camera from moisture and foreign objects according to the IP standard. Thanks to it, it is possible to select
waterproof models available for full outdoor use.
This protection describes how much the camera body protects sensitive internal components from these impacts. Standardly, it is denoted by the letters IP followed by two numbers. The first digit means protection against penetration of solid objects and dust; its individual values correspond to the following levels of protection:
1 - protection from objects with a diameter of more than 50 mm (large body surfaces)
2 - from objects with a diameter of more than 12.5 mm (fingers, etc.)
3 - from objects larger than 2.5 mm (most instruments)
4 - from objects more than 1 mm (almost all tools, most wires)
5 - dust protection (complete protection from contact; dust can penetrate inside, but does not affect the operation of the device)
6 - dust-tight (case with complete protection from dust and contact).
The second number characterizes protection against moisture, here the values can be as follows:
1 — protection from vertically falling drops of water;
2 - from water drops with a deviation of up to 15° from the vertical axis of the device;
3 - from water drops with a deviation of up to 60° from the vertical axis of the device (the minimum level that allows you to operate the c
...amera in the rain);
4 - from splashes from any direction;
5 - from jets from any direction;
6 - from sea waves or strong water jets;
7 - possibility of short-term immersion to a depth of up to 1 m (without the possibility of constant operation in submerged mode);
8 - possibility of long-term immersion to a depth of more than 1 m (with the possibility of constant operation in submerged mode).
Of course, surveillance cameras are usually not designed to be submerged under water - the last two options only characterize a high degree of moisture resistance.
In some models, one of the numbers may be replaced by the letter X - for example, IPX7. This does not mean that there is no protection, but that the corresponding parameter is not certified to the IP standard. At the same time, the degree of uncertified protection can be quite high - for example, the example above corresponds to the possibility of complete immersion under water, which requires a high degree of closure (at least dust resistance level 5). We also note that the complete absence of IP marking also does not mean that the camera is absolutely not protected from negative influences - again, the point is that the body simply did not undergo official certification. However, if dust and moisture protection are critical, you should choose among IP-certified models.RCA audio input
The number of
RCA audio inputs provided in the design of the complete recorder.
The presence of such connectors allows the recorder to receive an analogue audio signal from cameras that have the ability to capture sound, or from separately made microphones. It is worth looking for a set with such capabilities in cases where it is critical to record not only the picture, but also the sound during observation. Note that the number of RCA inputs may correspond to the number of BNC connectors (see above), but may be less.
Video compression format
The format in which the kit recorder records digital video.
This setting determines the codecs required to view content on external devices. When viewing on a computer with codecs, there are usually no problems: their set in modern operating systems is quite extensive, and the missing modules, usually, are easily found and installed via the Internet. But if you plan to view video materials through a media centre, a TV with direct playback via USB, etc. — It is worth making sure that this device supports the appropriate compression formats.
Technical details on different standards can be found in special sources.
