Comparison Hikvision DS-2CD1131-I vs Hikvision DS-2CD1031-I 2.8 mm

The case type describes not only its shape, but also some layout features that can affect the functionality of the product.

— Dome. In accordance with the name, on the body of such a camera there is a characteristic transparent dome, inside of which there is a lens — and, usually, controlled by PTZ (see "Camera capabilities"). The dome not only protects the optics from various adverse factors (such as dirt or moisture), but in many models it also hides the position of the lens; for this it is darkened. Thus, the object of observation does not know where the camera is pointed, which is useful in some cases (for example, when observing a suspicious visitor in a supermarket). At the same time, for a number of reasons, this option is poorly suited for advanced optics with large dimensions.

— Directed. Directional cameras are called cameras in which the lens "looks" along the body. This arrangement allows the use of powerful lenses with good aperture and optical zoom (see below), but the cameras are also quite bulky.

— Directional ( without a lens). A variation of the directional cameras described above, which has interchangeable lenses; The lenses themselves are usually not included in the kit, they must be purchased separately. The meaning of such a configuration is that the user can independently choose optics for specific needs. This categor...y includes mostly fairly advanced models.

— Hidden. This category includes cameras of a small size, which allows them to be installed discreetly — for example, in a wall niche. However, even with an external installation (this option, usually, is also allowed), such devices are also very inconspicuous due to the mentioned compactness. By itself, the body shape of hidden cameras is most often close to directional (see above), although there may be different options.

— Desktop. Cameras designed to be mounted on a tabletop or other flat, horizontal surface. For this, an appropriate stand is provided in the design; it can have movable mounts that allow you to tilt the camera and rotate it from side to side. The main advantage of such cameras is the utmost ease of installation; this, in particular, makes them almost perfect for home use.

— Portable with fastening. In fact, it is a kind of desktop cameras (see the relevant paragraph), in which the stand can be used not only for installation on a horizontal surface, but also for wall mounting. From other "wall" varieties — hidden and directional (see relevant paragraphs) — cameras of this type differ in layout: their body is usually flat, rectangular or oval, and the lens is located on the widest edge (similar to how it is done in mobile phones ). The mount is often made movable, to adjust for tilt and/or rotation.

Aperture of the lens installed in the camera.

Aperture characterizes the degree of attenuation of the light flux when passing from the front lens of the lens to the matrix. It is denoted as the ratio of the diameter of the active aperture of the lens to the focal length, while the size of the active aperture is designated as f and is taken as a unit — for example, f / 1.4 or f / 2.0. Moreover, the smaller the number in the designation, the higher the aperture (in our example, the second lens will be darker than the first). And for lenses with a variable focal length (see "Focal"), the actual aperture, usually, changes with a change in focal length; for such models, either the range of aperture values, or its maximum value, can be indicated.

By itself, this parameter characterizes, first of all, how light the image taken through the lens turns out, all other things being equal. High values are important, first of all, when shooting in low light conditions: a fast lens allows you to get a fairly high-quality image without increasing the sensitivity of the matrix, which is fraught with noise and “blurring” of the picture. On the other hand, the actual quality of camera operation (including in dark conditions) also depends on many other factors — the type and size of the matrix, signal processing features, etc. Therefore, aperture in most cases is more of a reference than a practically significant parameter.

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.

The ambient temperature range in which the camera can be used normally.

All modern surveillance cameras normally tolerate temperatures typical for houses / apartments, offices and other premises with similar mild conditions. Therefore, it is worth paying attention to this parameter, first of all, if the device is planned to be used outdoors — or in a room where the temperature does not differ much from the street temperature or, for technical reasons, should be low (freezer warehouse, refrigerated car, etc. ). In such cases, the lower temperature threshold is especially important: for example, almost all outdoor cameras have the ability to work in cold temperatures below 0 °, but among indoor models such features are much less common. However, frost-resistant devices(with an allowable temperature of -40 °C and below) can also be found not only among outdoor cameras, but also among “internal” cameras.

As for the upper temperature limit, it is usually not lower than +40 °C, which is quite enough for using the camera in a temperate climate. In some models, this limit reaches +50 °C and even +60 °C, making them suitable even for hot countries. However, note that we are talking exclusively about use in the shade; the possibility of working under direct sunlight should be clarified separately.

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.

Ruggedized housing providing enhanced protection against damage attempts.

The specific degree of strength may vary. For example, many manufacturers use the IK standard for impact resistance. The highest rating in this standard is IK10, providing protection against impact with an energy of up to 20 J, which corresponds to a 5 kg load falling from a height of 40 cm; more detailed information on IK can be found in special sources. At the same time, cameras that do not have IK certification can also be positioned as vandal-resistant.

Note that even the most vandalism-resistant housing does not provide absolute protection against damage. However, this feature, anyway, significantly complicates the attacker's task and may even force him to give up trying to permanently spoil the camera. And the purposeful removal of the camera from the system turns out to be a rather difficult and long matter. And in some models, the increased strength of the case can be combined with other features — for example, a sensor that sends an alarm when attempts are made to damage the camera.