Comparison Hikvision DS-2CE16C2T-IT3 vs Hikvision DS-2CE16A2P-IT3

The type of matrix installed in the surveillance camera.

— CMOS. Abbreviation for "complementary metal-oxide-semiconductor" (complementary metal-oxide-semiconductor structure, CMOS). The advantages of CMOS matrices are low cost, low power consumption, as well as high image processing speed and compact dimensions compared to CCDs. The main disadvantage of this technology is the increased image noise, especially at high sensitivity. To eliminate this shortcoming, there are various design tricks, but manufacturers often do not use them for the sake of the low cost of the camera. As a result, CMOS matrices are typical mainly for relatively inexpensive models.

— CCD. Abbreviation for "charge-coupled device" (charge-coupled device, CCD). This type of sensor is more expensive than CMOS and bulkier, but less prone to heat noise and generally more advanced. However CCDs don't handle point light sources very well; however, in this case, manufacturers just quite often use special technologies to neutralize this drawback. Such matrices are typical for advanced surveillance cameras.

— DIS. Abbreviation for "Digital Image System". The key feature of this type of matrices is that they combine both the photosensitive element itself and the image processor in one chip. This reduces the dimensions of cameras with DIS sensors and reduces their cost, while such devices can even surpass similar CCD and CMOS models in image quality. In addition, DIS matrices...are well tolerated by low temperatures (down to -40 °C), which is indispensable for outdoor cameras (see "Use").

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.

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.

Resolution of the video signal produced by the camera in TV lines (TVL).

A similar resolution designation is used for analogue video; the number of TV lines in this case is the horizontal size of the image. The meaning of such a recording is that in analogue PAL and NTSC formats, which are most often used in video surveillance systems, the vertical size of the video is always the same (625 and 525, respectively), so the frame size in different models of analogue cameras differs only in horizontal. Accordingly, the higher the TVL number, the more detailed the image will be, the more small details will be visible on it. On the other hand, in order to use all the features of a camera with numerous TV lines, a screen corresponding to these features is also required; For more details on compatibility with the screen, see specialized sources.

As for specific numbers, a value of 500 TVL and less is considered very small, 500 – 600 TVL — modest, 600 – 700 TVL — average, 700 – 800 TVL — above average, and in some models this number may exceed 800 TVL.

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.

The signal-to-noise ratio that the surveillance camera corresponds to.

This indicator describes the ratio of the level of the useful signal (the actual image produced by the camera to an external device) to the level of extraneous noise that inevitably arises during the operation of electronic circuits. Such noise appears in the image as characteristic noise (“snow”). The higher the signal-to-noise ratio, the less interference on the screen, the clearer and better the image is, and the smaller the volume of recorded video files. It is believed that visible noise practically disappears at a ratio of at least 45 dB. However, among modern cameras there are also higher rates.

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.

The main material used in the construction of the camera body.

— Plastic. Inexpensive and at the same time quite practical material. Plastic is light, quite strong (not as strong as metal, but still quite sufficient for most cases), chemically inert (and therefore not susceptible to corrosion and insensitive to moisture), and also has a relatively low thermal conductivity (which provides additional protection for extreme temperature fluctuations). Due to all this, this material is very popular in indoor chambers (see "Usage"). At the same time, it is somewhat less suitable for outdoor work.

— Metal. The main advantage of metal, in comparison with plastic, in the case of surveillance cameras is high strength and reliability. This allows you to use it even for street models that work in difficult conditions and must have a certain anti-vandal resistance (at least not immediately “give up” when trying to break or break). At the same time, such material is much more expensive, and therefore less common.