For video surveillance, electronic optical devices are used that monitor and automatically analyze images. The modern closed-circuit television complex uses the best surveillance cameras at local and distributed facilities. The situation at the facility is monitored, property is protected from criminals.
Solving problems using outdoor surveillance
According to the issued signal, the cameras are divided into digital and analog. The first type of modules is represented by IP cameras, transmits information by wire and without cable (Wi-Fi radio channel). The wireless view is equipped with a transmitter and antenna.
Division by design and features:
- modular cameras are available in the form of a printed single-layer board without a housing and are placed in hemispheres, thermocases;
- mini-video cameras are in small cylindrical or square cases, work inside buildings;
- housing devices are not equipped with a lens and fasteners; all required elements are additionally purchased;
- The round dome or hemisphere dome camera is made of metal or plastic.
High-speed installations with control combine a zoom, a video camera, a camera, a rotary mechanism. Gyrostabilized modules are used on moving objects.
Surveillance Camera Selection
Lenses are monofocal and varifocal. The former have constant focus, the latter transform the focal length manually or using the remote control. The aperture in the lenses is fixed and controlled.
You can choose video surveillance according to the operating conditions:
- the dome is placed for internal observation;
- Thermo-jacket protects from cold and precipitation;
- anti-vandal box protects against damage.
The means by which the picture is issued matters. Devices come with a serial video switcher, multiplexer, matrix. The image is recorded by a VCR, digital or other recorder.
Criteria for choosing a camera for the street
It is difficult to select due to the large assortment of equipment with advanced functionality. An outdoor video device provides a high-quality overview of the perimeter, while the costs of acquisition and operation should be minimally acceptable.
Attention is paid to the characteristics:
- level of protection against frost, sun, precipitation, icing;
- remoteness of the camera from the monitor-receiver;
- distance transmission ability without quality degradation.
Outdoor video devices are equipped with thermal imagers, automatic cameras, microphones.
Permissible operating temperature range
The operation of the electronics goes astray when the temperature drops below -10 ° C. Special casings are used with internal heating and protection against dampness and dust flows, so that the equipment works efficiently at -30 - -35 ° C.
You can choose a CCTV camera for the street with various protection:
- universal heaters, the heating of which does not depend on the functional system of the device;
- Thermocase, which is an integral part of the video device.
To choose correctly, you need to evaluate the materials of the insulation case and gaskets for brittleness, cracking. Sealed cable glands should be located below, there should be a condensate collector. The visor must be selected so that it covers the entire housing of the tracking module.
Vandal proof
The system protects the cameras from mechanical damage, the devices have an IK 10 protection standard and work, despite attempts to hack. Vision devices must be installed high, while the attempt of the offender to gain access to the device will attract double attention.
If the device does not have anti-vandal protection, it must be placed in special durable structures. Some owners hide cameras from criminals, but this has the opposite effect of encouraging impunity. The solution is that a non-working device is placed in a prominent place, which the criminal breaks, and his actions are removed by a hidden working chamber.
Resolution
Resolution also determines the choice of CCTV camera for the street, the characteristic is measured in pixels. The property shows the ability to fix, display the number of points in an inch of the frame surface vertically and horizontally. Decreased resolution degrades quality and vice versa.
The best resolution is 4k, but a system with such parameters will be expensive, including a hard drive, monitor, DVR, and recordings take up more disk space. Modern video devices use the old D1 and CIF in the form of a substream. This is a stream with a lower resolution for receiving images from multiple cameras, which allows you to work at low speed Internet. Quality changes in a special menu.
Viewing angle
The characteristic determines the overview of CCTV cameras and the type of picture, which can be portrait, approximate or panoramic. As the angle decreases, the quality of focusing increases, so you can consider individuals, but the situation in the apartment is poorly visible.
For viewing at a distance of 40 meters, a viewing angle of up to 45 ° is selected. For a complete coverage of the situation, it is recommended to take an angle above 90 °. Cameras with a variable radius of coverage cost one and a half times more. The viewing angle depends on the matrix index and the focal length of the device. There is a special table where this relationship is traced. The purchase coverage angle can be obtained from the seller or see the technical documents.
Type of shell
Frameless cameras have a single board design and a small lens. They can be installed in decorative elements, embedded in the wall. Security cameras for the protection of a private house, which are installed on the street, are enclosed in a warm building. This type is one of the most inexpensive devices for video surveillance.
The advantages include:
- simplicity of installation and connection;
- can be installed in intercom systems;
- decent video quality.
Electronic devices weigh 20 - 40 g, therefore they are mounted in any area, for example, on the ceiling, where no one will notice them. There are devices with 1 to 3 boards, unpacked modules differ in the types of landing nests.
Sensitivity
The indicator depends on the minimum aperture, through which a signal of size 1V with an illumination of 2000 lux, a color temperature of 3200K according to the test table is supplied. The sensitivity of the camera is often taken as another parameter - the minimum illumination. This index is expressed in lux and indicates the acceptable light level in the area at which the device produces a recognizable video signal.
Some equipment manufacturers do not characterize the level of output teams and use the term in different ways. If the tracking module operates at night and there are no other lamps, the sensitivity to light should be up to 0.01 lux.
Additional functions
Surveillance systems solve several problems, in addition to conventional video recording and playback. Combined schemes include a combination of safe measures to protect the site, records are used in court to confirm the facts.
Additional features:
- local and remote audio-video control;
- approach control schemes, remote access systems, coordination;
- control of the actual time of work;
- information about the presence of employees;
- recognition of numbers of cars.
Video surveillance systems are combined with fire alarms, used as protection against radio listening, for finding fuses, monitoring the telephone line.
Installation and operation
Efficiency depends on the correct installation. The norms are different for each class, but there is a standard regulation for all types. The place is chosen so that the entire area is covered and there is little exposure.
Connecting wires are laid no closer than 0.5 m from the power cables. To transmit an analog image over 100 meters, not a coaxial wire, but a twisted pair cable is used. The street signal circuit is protected against interference from the electrical main.
Rating and review of outdoor CCTV cameras
Devices with an energy resolution of 1 - 2 megapixels and low color rendering and sensitivity fall into the economy class category. The leader in the rating is products at prices of 2-6 thousand rubles from Axilium, Rvi, Novicam, Space Technology, Prime, Fazera, Optimus.
The business class presents products of high photosensitivity and color reproduction, with clear illumination and a resolution of 1080 x 1920 pixels. The cost varies between 6 - 30 thousand rubles. Top manufacturers include Microdigital, Dahua, D-link, Ever Focus, Beward, Falcon Eye, Divitec, Etrovision.
Premium video surveillance includes modules worth more than 1.5 million rubles with impeccable characteristics and a degree of reliability. They have maximum hardware, 360 ° all-round visibility, and smart functionalities. The ranking includes manufacturers of Bosch, Beward, AXIS, Hikvision, Dahua, Panasonic, Microdigital, Samsung.
