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.
Matrix size
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.
Resolution
Resolution of the analogue video output from the included pointed cameras. In the most popular modern analogue video formats — PAL and NTSC — the vertical frame size (number of lines) is standard. Therefore, the resolution of such a video is indicated by only one digit — the number of TV lines (TVL), corresponding to the horizontal size.
Higher resolution improves the visibility of fine details; however, it is worth remembering that in order to fully view such a video, you will also need a screen with the appropriate characteristics. And this parameter also significantly affects the cost of the camera.
Number of megapixels
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
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.
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.
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).
