Number of LEDs
The number of backlight LEDs (see "Design and capabilities") provided in the camera design.
Theoretically, more LEDs provide more power and, accordingly, range (see below) and efficiency
of IR illumination or LED illumination. However, in fact, such light sources can vary markedly in performance; in addition, a lot also depends on the features of the camera itself. Therefore, in fact, this indicator is a reference, and when choosing, it makes sense to pay attention to parameters that are closer to practice — in particular, the same backlight range (see below).
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.
Horizontal viewing angle
Horizontal viewing angle of the surveillance camera. For models with a variable value, the maximum value is indicated, since it is the width of the image that is important, and when zooming in, the zoom factor is more important than the angle. This paragraph also indicates the general angle of view for models with a circular field of view – in particular, cameras with a fisheye lens (see above)
The wider the viewing angle, the more space the camera captures and at the same time, the smaller the images of individual objects in the frame are obtained. Therefore, when choosing by this parameter, it is worth deciding what is more important – the ability to view a large scene or the visibility of small details in a relatively narrow field of view. Also note that with a wide field of view (100° or more), characteristic distortions can be observed at the edges of the frame, and the wider the angle, the more pronounced they are. This phenomenon can be eliminated by panoramic shooting (see "Design and features"), but this feature, in turn, complicates and increases the cost of the camera.
Vertical viewing angle
Vertical viewing angle of the surveillance camera. In models with a variable value, the maximum is indicated, and the angle when zooming is not so important.
The wider the viewing angle, the more space the camera captures and at the same time, the smaller the images of individual objects in the frame are obtained. Therefore, when choosing by this parameter, it is worth deciding what is more important – the ability to view a large scene or the visibility of small details in a relatively narrow field of view.
Video compression format
The video compression format used by the camera.
Compression is used to reduce the file sizes of captured video; different technologies can be used for this — the so-called codecs, their list is given in this paragraph. From a practical point of view, compatibility with external recording and playback devices primarily depends on the supported codecs. If you plan to use a computer as a recorder / player, you can ignore this list: modern PCs and laptops usually support a very extensive list of formats, and in extreme cases, the missing codecs can be installed separately. But if we are talking about specialized registrars, individual players (like home media centers), etc. — codec compatibility should be clarified further. So, if the advanced modern
H.265 standard is very widely supported nowadays, then the more specific
H.265+, originally created for surveillance systems, is much less common even in specialized equipment.
Power source
The voltage or type of power used by the camera.
It is worth saying that among such equipment it is quite rare to find models originally designed for
230 V - devices with lower supply voltages are much more widespread, in particular,
5 V,
6.5 V,
9 V,
12 V,
14 V and
24 V. To operate such a camera from an outlet, you will need a power supply; it may be included in the delivery package, but this point should be clarified separately. More specific methods of supplying energy are also possible - for example, through a specially organized low-voltage network, or from a car battery (for 12- and 24-volt models). Separately, we note that when operating via POE (see “Design and capabilities”) the supply voltage is standard 48 V, so for models with POE the power supply features are not specified.
A specific category is represented by
battery-powered cameras. This power supply ensures autonomy and independence from wires, but the operating time is limited - when the charge is depleted, the camera will have to be connected to an energy source to charge the battery. Therefore, very few battery models are produced - mostly these are compact solutions with a wireless connection, for example, via Wi-Fi
...(see above).
Another extraordinary option is cameras powered by a solar panel. Autonomous power supply from solar panels is used in outdoor models of CCTV cameras. During the day, they are supplied with energy from the sun's rays and at the same time accumulate a charge in the battery, which is enough to ensure the operation of the video surveillance system at night. To meet your own needs, solar panels are placed directly on the camera body or somewhere next to it. Cameras powered by solar energy are the best option for installation away from electrical civilization.Maximum humidity
The highest relative humidity at which the camera is able to operate normally, without failures and breakdowns, for an unlimited time.
Modern electronics tolerate low humidity well, but high rates affect it negatively — with a long stay in such an atmosphere, moisture can condense on certain parts of the structure and various unpleasant consequences, from corrosion to short circuits and fires. Therefore, you can use the camera effectively and safely only in conditions where the humidity does not exceed the maximum recommended value specified in the specifications. At the same time, we note that many devices are able to endure short-term (up to several hours) exposure to high humidity without consequences.