Max. memory card size
The largest capacity of a memory card with which a video surveillance camera can work correctly.
High-capacity drives require fairly high processing power and may use special technologies that are not supported by all cameras. This is the reason for the limitation on the volume of supported media.
Active protection
Active protection methods implemented in the camera.
By itself, this function is intended to cause discomfort to the attacker and scare him away, as well as draw attention to the situation. It can be activated both manually and automatically (for example, by a motion sensor or a signal to the alarm input of the camera). There are two main types of active protection:
— Light (strobe). A bright light source that flashes at a rate of several flashes per second. Immediately after turning on, the strobe is capable of disorienting a person for several seconds, and even after that, the flashing light makes it difficult to coordinate and move quickly; all this can give security officers additional time to react to the situation. In addition, flashes are clearly visible not only with a direct look, but also with peripheral vision, and in the form of reflections.
— Sound (siren). A loud beep that is almost guaranteed to attract the attention of people nearby. In some models, the volume of the siren reaches 110 dB — this is comparable to the engine of an old tractor and only slightly below the pain threshold of a person.
Each of these options has its own advantages, and it is not difficult to combine them in one device. Therefore, most modern cameras with active protection use both methods described above at once.
Matrix size
The size of the matrix installed in the surveillance camera (diagonally).
In general, larger sensors (with the same resolution and sensor type) are considered more advanced: they get more light, which has a positive effect on image quality (especially in low light). On the other hand, increasing the size affects the cost of the entire device; and in some cases (for example, if the camera is not planned to be used in twilight and darkness), a relatively small sensor may be quite suitable.
As for specific dimensions, the most modest cameras in terms of this indicator have matrices of
1/4 "or less. Models with sensors of
1/3.8" - 1/3" and
1/2.9" - 1/2" are very popular, these values can be called average. And in advanced devices, diagonals and
more than 1/2 "(up to 1/1.7") are found.
Number of megapixels
Camera sensor resolution in megapixels (millions of pixels).
The higher the resolution of the matrix, the higher the video resolution can be (see below), the more detailed the image is capable of providing the camera. At the same time, note that as the number of megapixels increases (without changing the size of the matrix), the size of each individual pixel decreases, which increases the likelihood of noise and deterioration in the overall image quality. Therefore, high resolution in itself is not necessarily a sign of high quality — a lot depends on other things, for example, on the size of the matrix (see above).
As for specific values, in the most modest matrices it does not exceed 1.3 MP, which corresponds to the maximum
HD resolution.
2 MP sensors allow for already Full HD resolution (usually 1920x1080 or 1600x1200),
3 MP,
4 MP,
5 MP and
6 MP are capable of better resolution, but still do not reach
4K, which is typical for 8 MP.
Video resolution
The maximum video resolution that the camera can capture.
The higher the resolution of the video, the more details you can see on it, the less details will be blurry. On the other hand, high resolution means large volumes of video materials, which, accordingly, requires capacious media for their storage and fast communication channels for broadcasting video in real time. Yes, and this indicator significantly affects the cost of the camera.
Frame rate
The maximum frame rate in the video captured by the camera.
The higher the frame rate, the clearer the image, the less noticeable blurring when moving in the frame (especially fast). On the other hand, this indicator affects the amount of information recorded during shooting, as well as the cost of the camera itself. Therefore, it makes sense to specifically look for
a video surveillance camera with high-speed shooting(45 fps and higher) only if a clear recording of fast moving objects is important to you.
ONVIF
ONVIF in this case is a set of rules (protocols) for the interaction of different components of a video surveillance system. This set was developed by the organization of the same name (Open Network Video Interface Forum) and is widely used in equipment from different manufacturers. In the case of cameras, this means that an
ONVIF-compliant camera will be able to work properly with any brand of equipment, as long as it also supports this standard.
