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.
Illumination range
Operating range of the backlight (see "Design and capabilities") installed in the surveillance camera. This term usually means the maximum distance from the camera to the observed object, at which it is able to provide a relatively high-quality and legible image in the complete absence of other light sources. Of course, the actual backlight range may differ from the claimed one, and these differences are most often in the direction of increase (for example, due to the presence of the same additional light sources). However, if the possibility of shooting with backlight is important for you, you should focus on the claimed range.
Smart features
Functions that automate the process of video monitoring, analysis and response to events, which helps to minimize the human factor and increase the efficiency of video surveillance systems.
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Perimeter protection. This option is used when deploying complex video surveillance systems with a recorder and cameras, combining the expanded functionality of intelligent video analytics capabilities for monitoring boundaries. Perimeter protection can cover various functions, for example, tracking the intersection of virtual lines, the appearance or disappearance of objects in the frame, setting up protected zones, if the boundaries of which are violated, an alarm will be activated, and so on. The full list of features should be specified separately. It is important to note that for the listed functions, analysis of objects in the frame can be used - detection of people, classification of vehicles, etc.
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Definition of a person. Cameras with this function can detect the presence of people in the frame by the characteristic outlines of their silhouettes. Once a person's presence is detected, an alarm can be activated, and moving PTZ cameras can follow people in the frame.
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Definition of a car. The ability of a video surveillance camera to automatically recognize and highlight objects in the frame that are vehicles. This can be useful for monitoring t
...raffic, controlling parking, or ensuring the safety of roads within a controlled perimeter. A more advanced implementation of this function is license plate recognition (see below).
— Definition of animal. The function of identifying various “living creatures” in the frame: pets, neighbor’s cats and dogs, alien wild animals, etc. Video surveillance systems with this functionality can be used to minimize false alarms, monitor pets to make sure they are safe and in order, and to solve other similar problems.
— License plate recognition. Special tools that provide additional capabilities for reading license plates. The specific capabilities of such tools may be different in different models; they should be clarified separately. So, some cameras only read letters and numbers and transmit the information to the recorder for further processing. Others have built-in databases, so they can compare the read number with the base and provide various actions depending on the result - for example, send a signal to open the barrier if the number is “allowed”. However, in any case, cameras with this feature are well suited for objects where it is necessary to control the movement of cars - for example, parking lots (including closed service ones).
— Facial recognition. Cameras with this function are able to at least recognize the presence of faces in the frame; but the further use of this data and the special functionality of such cameras may be different. Thus, relatively simple models react only to the very fact of detecting a face, but even this provides quite extensive additional capabilities: focusing on a face, tracking a person in the frame (in moving PTZ cameras), etc. And more advanced cameras can recognize characteristic features faces by which a specific person can be identified. This functionality, among other things, allows the surveillance system to compare the faces “seen” by the camera with the stored database and take various actions based on this - for example, allow or deny access, warn about an unwanted visitor or unauthorized use of a key card, etc. P.
Note that face recognition tools can also be found in recorders to which cameras are connected. However, the presence of such functions in the cameras themselves can also be useful - especially if the existing recorder “does not shine with capabilities” in this regard, or the system does not have a recorder at all (for example, it consists of IP cameras connected via a router to a PC).
— People counting. A function that allows the camera to count the number of people in the frame; the received data is stored in its own memory and can be sent to a recorder or other external device. Note that in most models this feature is combined with the face recognition described above, thanks to which the camera is able not only to count all people in a row, but to recognize tech who are in the frame again. However, people counting can be used for both statistical and security purposes. For example, at large facilities such as office and shopping centers, it allows you to determine whether all visitors who entered the premises left it before the end of working hours.Smart home system integration
Smart home systems that the camera is compatible with.
The general principle of all such systems is to combine various home electronics and household electrical appliances into a single complex so that all these devices can interact with each other and jointly respond to various events. As for surveillance cameras specifically, their functions in a “smart home” are mainly related to reacting to movement in the frame and broadcasting video. For example, a compatible camera can send a notification to the user’s smartphone when a motion sensor is triggered, or transmit video to a TV integrated into the home network.
Nowadays you can find different smart home platforms, the most popular are Apple HomeKit, Google Home, Amazon Alexa. However, there are other options for branded systems - as a rule, they are sold by manufacturers for their smart home and video surveillance devices. To fully work in a particular system, it is worth using cameras that have expressly stated appropriate compatibility. Also, when purchasing a compatible model, it would not hurt to clarify its specific functionality related to the “smart home”.
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.
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.
Minimum illumination
The lowest degree of illumination of the scene being shot, in which the camera is able to provide normal visibility. Usually, this item specifies the values for the daytime mode of operation (in the night mode, the minimum illumination in many models may be zero at all, because in such cases the IR illumination is turned on, see "Design and capabilities"). And if the camera is capable of shooting in colour, it usually means the lowest illumination necessary to obtain a colour image.
The lower this indicator, the better the camera works in low light, the brighter and more clearly visible image it is able to provide in such conditions. At the same time, note that in low light, night mode is often preferable, and in the presence of the aforementioned IR illumination, it is more likely to focus on the range of its operation (see above).
There are comparative tables that allow you to evaluate the degree of illumination indicated in the characteristics from a practical point of view: for example, an indicator of 0.2 lux corresponds to clear eyes on a full moon.
Backlight compensation
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WDR (Wide Dynamic Range) — extended dynamic range. WDR technology combines several frames with different exposures into one picture, as a result, dark areas are brightened, and overexposures are darkened, and the output is a picture with extremely uniform lighting. The true wide dynamic range technology is called True-WDR and it is implemented in the optical circuit at the hardware level, a special microprocessor is responsible for creating and mixing exposures. A more affordable alternative to wide dynamic range is Digital-WDR technology, which equalizes lighting through software algorithms.
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DWDR (Digital Wide Dynamic Range) — extended dynamic range technology based on software brightening algorithms. DWDR brightens too dark areas of the frame, which can be completely blurred against the background of light areas. Digital brightening allows you to noticeably improve the quality of shooting in contrasting lighting conditions. Digital WDR cameras are noticeably cheaper than true True-WDR optics. Of course, the quality of digital brightening is inferior to True-WDR.
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BLC (Back Light Compensation) — backlight compensation technology. This system is based on the work of digital signal processors DSP. So, the device, relatively speaking, "breaks" the frame into many segments, making its own adjustments to each of them. Backlight compensation brightens dark areas of
...the frame well. The main disadvantage of the technology is the increase in the brightness of the already bright areas of the frame, due to which overexposure may appear in the picture.
— WDR+BLC. The camcorder supports several lightening technologies at once, each of which is described in more detail above. Immediately, we note that the combination of WDR + BLC allows you to achieve an extremely clear and clear picture in almost any lighting conditions, from extreme contrast to insufficient and excessively bright.
— DWDR+BLC. The device supports two popular clarification technologies at once, each of which is described in more detail above. The presence of DWDR + BLC technologies allows the camera to effectively brighten the dark areas of the frame. Such video cameras have proven themselves well when working in low light conditions."Fish eye"
The presence of a
fisheye lens in the camera. Such a lens provides a very wide field of view — about 180 ° in all directions. Thanks to this, you can, for example, mount the camera on the ceiling and cover the entire room with it. At the same time, such models are much cheaper and more compact than devices with panoramic shooting (see the relevant paragraph), since there is only one lens in the fisheye camera. However fisheye optics give strong distortions at the edges of the image; however, this point is rarely critical in fact, and fisheye cameras are very popular in modern surveillance systems.