Dome cameras
The number of dome cameras supplied as standard with the video surveillance kit. For more information about this variety, see "Type of cameras", here we note that the total number of cameras in the set (both pointed and dome cameras), usually, is less than the number of video channels (see above). This allows you to buy additional cameras if necessary, and the user can choose them at his discretion.
Camera model
A model of dome cameras supplied as standard with a video surveillance kit. Knowing this data, you can find detailed information on the cameras and clarify their characteristics. In addition, by purchasing additional cameras of the same model, you don't have to worry about compatibility.
Matrix size
The physical size of the sensor in the complete dome 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.
Number of megapixels
Resolution of sensors of complete dome 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 dome camera lens included in the kit.
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
Viewing angle of the dome cameras supplied as standard, horizontally.
Wide viewing angles allow you to cover more space. On the other hand, ceteris paribus, a larger viewing angle will mean a smaller degree of magnification — objects will look smaller, detail will be worse. Therefore, when choosing for this parameter, it is worth proceeding from what is more important — an extensive field of view or "range".
Water resistance
The degree of protection of the camera from moisture and foreign objects according to the IP standard. Thanks to it, it is possible to select
waterproof models available for full outdoor use.
This protection describes how much the camera body protects sensitive internal components from these impacts. Standardly, it is denoted by the letters IP followed by two numbers. The first digit means protection against penetration of solid objects and dust; its individual values correspond to the following levels of protection:
1 - protection from objects with a diameter of more than 50 mm (large body surfaces)
2 - from objects with a diameter of more than 12.5 mm (fingers, etc.)
3 - from objects larger than 2.5 mm (most instruments)
4 - from objects more than 1 mm (almost all tools, most wires)
5 - dust protection (complete protection from contact; dust can penetrate inside, but does not affect the operation of the device)
6 - dust-tight (case with complete protection from dust and contact).
The second number characterizes protection against moisture, here the values can be as follows:
1 — protection from vertically falling drops of water;
2 - from water drops with a deviation of up to 15° from the vertical axis of the device;
3 - from water drops with a deviation of up to 60° from the vertical axis of the device (the minimum level that allows you to operate th
...e camera in the rain);
4 - from splashes from any direction;
5 - from jets from any direction;
6 - from sea waves or strong water jets;
7 - possibility of short-term immersion to a depth of up to 1 m (without the possibility of constant operation in submerged mode);
8 - possibility of long-term immersion to a depth of more than 1 m (with the possibility of constant operation in submerged mode).
Of course, surveillance cameras are usually not designed to be submerged under water - the last two options only characterize a high degree of moisture resistance.
In some models, one of the numbers may be replaced by the letter X - for example, IPX7. This does not mean that there is no protection, but that the corresponding parameter is not certified to the IP standard. At the same time, the degree of uncertified protection can be quite high - for example, the example above corresponds to the possibility of complete immersion under water, which requires a high degree of closure (at least dust resistance level 5). We also note that the complete absence of IP marking also does not mean that the camera is absolutely not protected from negative influences - again, the point is that the body simply did not undergo official certification. However, if dust and moisture protection are critical, you should choose among IP-certified models.
