Max. capacity
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.
Focal length
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.
Horizontal viewing angle
The viewing angle of the directional cameras supplied as standard is horizontal.
Wide viewing angles allow you to cover a large area; this is especially important given that directional cameras are often made stationary. On the other hand, all other things being equal, a larger viewing angle will mean a lower degree of magnification - objects will look smaller, detail will be worse. Therefore, when choosing according to this parameter, you should proceed from what is more important - a wide field of view or “range”.
Illumination range
The range of infrared illumination provided in the standard pointed cameras of the kit.
IR illumination allows the camera to shoot in low light conditions (up to complete darkness); at the same time, for a number of reasons, it is preferable to classical backlighting in the visible range. The backlight range is the approximate distance from the camera to the object at which it (in total darkness) will be normally visible in the frame. Note that actual visibility may vary greatly depending on the size, colour and reflectivity of specific items; Nevertheless, the claimed backlight range allows you to fairly accurately assess the "night" characteristics of the camera.
PTZ (managed)
Support of the complete registrar of controllable
PTZ cameras.
Lenses in such cameras are able to rotate from side to side and up and down, as well as change the degree of image magnification (however, not optics, but digital zoom may be responsible for the latter). Thus, the area covered is significantly expanded (although part of it is constantly behind the scenes), and the operator can direct the camera to the point of interest to him. In addition, the movement of cameras can be automated — for example, programmed to constantly turn from side to side, to aim at the door when the lock is triggered, etc.
Support by the PTZ recorder is mandatory for the normal operation of cameras with this function. At the same time, the controlled cameras themselves in this case may be included in the kit, but this is not necessary, so their presence should be specified separately.
Recording resolution
The maximum frame resolution in which the complete recorder can record video if all video channels are involved in operation. In fact, we are talking about the highest resolution in maximum load mode; if some channels are idle, some models allow higher resolutions. However, it is customary to indicate this parameter in the specifications - it most accurately characterizes the capabilities of the device.
As for the resolution itself, the higher it is, the more detailed the image is; on the other hand, such video requires significant processing power and capacious storage drives, which affects the final cost of the equipment.
Popular maximum frame resolutions in which modern recorders record:
HD (720),
Full HD (1080),
Quad HD,
Ultra HD (4K).
