Comparison Tecsar AHD 8IN 2MEGA vs Atis WiFi KIT 81

This parameter refers to the included DVR and describes the types of video signal (and therefore cameras) with which it is compatible. In some cases, the model is also indicated - for connoisseurs of the matter. So you can learn more about the capabilities of the device on specialized sources.

- Analog. Recorders capable of working only with analog cameras, usually connected via the BNC interface (see below). The functionality of such devices is less extensive than in digital and hybrid models, but they are simple, inexpensive and quite capable of coping with basic video surveillance tasks. We also note that a modern analog recorder usually has video outputs and service interfaces in a digital format - primarily HDMI and LAN (see below).

- Digital. Recorders designed to work with IP cameras - that is, cameras that transmit video signal through computer networks. This signal format provides improved noise immunity and a greater number of additional features compared to analog. In addition, it allows you to build video surveillance systems based on existing local networks, and cameras can be connected not only by wire, but also wirelessly (see below for more details). On the other hand, digital recorders and cameras are more expensive than analog ones, advanced functionality is not often needed in practice, and the transfer of a large number of video streams can create a high load on net...work equipment. Therefore, it makes sense to purchase such a recorder only if the described advantages have crucial.

- Hybrid. Recorders that combine the capabilities of analog and digital models - that is, compatible with both analog and IP cameras. This combination allows you to combine the advantages of both types and partly compensate for the shortcomings, but significantly increases the price of the registrar.

The type of cameras supplied as standard with the video surveillance kit.

— Directional. Directional cameras are those in which the lens "looks" along the body. This arrangement allows the use of powerful lenses with good aperture and optical zoom (see below), but the cameras are also quite bulky.

— Dome. As the name suggests, the body of such a camera has a characteristic transparent dome, inside which there is a lens — usually controlled by PTZ. The dome not only protects the optics from various adverse factors (for example, dirt or moisture), but in many models it also hides the position of the lens; for this purpose, it is made dark. Thus, the object of observation does not know where the camera is directed, which is useful in some cases (for example, when observing a suspicious visitor in a supermarket). At the same time, for a number of reasons, this option is poorly suited for advanced optics that are large in size.

— Directional and dome. The presence of two types of cameras in the kit at once allows you to build a video surveillance system "out of the box" that covers both indoor and outdoor spaces. The details of each type are described above.

The standard way to connect cameras, provided in the video surveillance kit.

- Wired. This type of connection requires wiring from each camera, which is not very convenient. At the same time, wired devices are simple, reliable and much cheaper than wireless ones, cameras can receive the power needed for operation via the same wires (see "POE power"), and for an analogue connection (see "Type") this is generally the only available option. Due to this, the vast majority of modern surveillance systems use a wired connection.

- Wireless. Wireless connection, usually via Wi-Fi. This option greatly simplifies the installation of cameras, because. the user is relieved of the need to lay wires to the registrar. On the other hand, wireless equipment is not cheap, and the cameras will still need to be connected to power sources (or use their own batteries, which will have to be monitored). Therefore, this option has not received much distribution, it is designed mainly for those cases where the ability to do without extra wires is decisive.

The largest storage capacity with which the recorder is able to work normally.

The more capacious the drive, the higher the processing power of the system in which it is used should be. Therefore, any modern registrar has limitations on disk capacity. However, even in the most modest models, this figure is about 2 TB, in most cases this is quite enough to work with the capabilities provided in this particular registrar.

The number of pointed cameras that are standardly supplied with the video surveillance kit. For more information about this variety, see "Type of cameras", here we note that the total number of cameras in the set (both pointed and dome cameras), usually, is less than the number of video channels (see above). This allows you to buy additional cameras if necessary, choosing them at your discretion.

The type of matrices used in pointed 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. In addition, DIS matrices are resistant to low temperatures, which makes them especially suitable for outdoor applications.

The physical size of the sensor in the pointed 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.

Sensor resolution of pointed cameras in megapixels (millions of pixels).

Higher resolution allows you to get a more detailed "picture". However, increasing the number of megapixels without increasing the sensor size can result in poor overall image quality and noise, especially in low light. Therefore, in itself, the high resolution of the matrix does not guarantee high quality shooting.

Focal length of the lens of pointed cameras included in the set.

The focal length is the distance between the lens and the matrix, at which the image on the sensor is as clear as possible (when the lens is focused to infinity). This indicator directly affects the viewing angles and the degree of magnification: the larger the focal length, the narrower the viewing angle and the more the camera "brings" the object. At the same time, it should be noted that the actual viewing angle is determined not only by the focal length, but also by the size of the matrix (see above). In fact, this means that with different sizes of matrices, lenses with the same focal length will have different working angles. Therefore, only cameras with the same matrix size can be compared with each other according to this indicator.