Surveillance Camera: types, functions, how to choose, manufacturers

The principle of operation of CCTV cameras - image transmission through the lens, and special filters to the image sensor.

The image from the image sensor as an electrical signal supplied to the processor which, after the information processing by the corresponding output passes it to the DVR, video server, the monitor of the operator, in the cloud or on mobile device.

Types of CCTV cameras

Depending on the location and conditions of use of the camera is divided into:

• External.

(Used for outdoor installation), to the external video cameras make high demands on protection against adverse external influences: moisture, dust and low temperatures.

• Internal.

(Used for indoor applications) have a lower degree of protection against dust and moisture, does not require during installation and heating the sealed housing.

According to the type of the camera body is divided into:

dome. As the name implies, the housing is shaped as a hemisphere or dome. This form of housing is suitable for installation in indoor and outdoor use. The housing dome is fixed on a wall or ceiling without the need to install special brackets. Adjusting the position in this case takes a little time - just need to remove the housing cover and select the position of the lens.

cylindrical. The housing has a shape of a cylinder, to protect the lens from the exposure of these are equipped with a visor body, the position of which is adjustable on some models.

rotary (Or speed dome) lens position is controlled remotely. They consist of an arm on which is mounted a spherical body whose upper part is made of metal or plastic, and the bottom hemisphere of transparent plastic or acrylic, which allows the lens to freely rotate 360 ​​degrees, changing the horizontal and vertical position.

hidden. They are small in size in comparison with the dome and the cylindrical chamber (3-4 times less than the standard) for easy selection manufacturers offer wired, wireless camera and self-powered by a battery or rechargeable battery that will last for 4-6 hours work.

Also hidden cameras can work on GSM channel, transmitting the video stream to a smartphone, tablet or laptop, or record on the built-in memory card.

By type of surveillance device is connected is divided into:

• Analog, where the connection occurs through koaksikalnogo cable. The image enters the CCD video camera, is processed by processor (DSP - Digital Signal Processor), which converts the image in analog television signal and transmits via BNC video output signal to an operator monitor or recorder. With this type of connection of the camera signal is converted into a binary code.
• Digital where the connection occurs by means of the twisted pair. Wherein after image processing is converted into a digital video signal, which is transmitted to the video server or DVR.
• Wi-FiWhere connectivity is provided by a built-in wireless module. Wireless connection is used in the portable cameras in locations where wiring is difficult or impossible.

Function CCTV cameras

Modern video surveillance systems are equipped with many features that are designed to simplify the installation, setup and operation of surveillance systems and to facilitate the implementation of operator tasks on the Protection and Control.

PTZ control. Reducing PTZ stands for Pan-tilt-zoom, which translates as panaramirovanie, tilt and zoom (zoom in). The cameras of this type it is possible to remotely control the position of the lens to adjust the approach and focus of the camera from the operator's seat.

In common parlance is called PTZ PTZ.

To automate the surveillance of rotary models can be customized route monitoring when the device will change its status after a specified time itself. when configuring the operator himself determines the points that deserve the most attention, and the time interval through which the camera will change its position.

PoE power supply (Power over Ethernet) literally stands for "power over (on) the Internet." PoE allows for the same twisted pair to transmit IP camera power supply, which is transmitted by video stream and operate two pairs of standard 100Base-TX, which are used for data transmission of the four. For two untapped couples and energized.

This is especially useful when it comes to street cameras.

The following types of devices are used for the organization of PoE power:

• PoE injector. The network device with two ports and connection to the mains. The first port is connected to the switch. The second port is connected IP-camera, the power transmitted on the same port. (Strands of 1,2,3 and 6, data is transmitted through the veins 4,5,7,8 device is powered on).
• PoE Switch. Switch with integrated PoE injector, in which the port is used for both data transmission and power supply. (Quantity of PoE ports depends on the product model)

Defining PoE connection.

In order not to apply voltage to the device that consumes no power over twisted pair, in PoE equipment is used to connect stage, which is designed to determine that the device is consumer.

On the basis of this determined value of the input resistance. Thereafter, the injector or switch delivers full power to the device.

To prevent failure of the cameras or other consumer, the PoE equipment continuously monitors the overcurrent to a heavy load to remove stress from the port.

Thus, if a PoE port to connect your device, do not consume power, the power supplied to it will not be, and the device does not fail.

Light sensor. Many video cameras are equipped with a light sensor, which controls the automatic switching infrared light in low light level or in the dark. The sensor consists of a photodiode, which is installed in the vicinity of the camera lens and the relay.

When changing the light flux relay, which sends a signal to switch the infrared light. Use of the light sensor enables the clock to obtain acceptable image quality in an automatic mode.

Motion detection. Detector or motion sensor called a special software module embedded in the software or from the DVR. In the event of motion detection performed by the programmed actions operator Entry archive, alarm notification, or removing images on a special "call monitor" the protection or operator.

Modern video surveillance devices can detect not just the movement, as well as the volume of the moving object and its color. For example, you can specify the pattern by which the camera will trigger the emergence of the human frame, in a black T-shirt and light trousers.

Also, the camera software and DVR allows you to create so-called "mask" itself-choose area of ​​the composition, which will be monitored by the motion, thus reducing the number of unwanted positives.

Microphone. When installing an alarm system and video surveillance are often besides the image from the cameras need to hear what's happening in the scene. Sound together with the video allows to compile the most complete picture of the events that need to be analyzed.

In addition, the audio recording will be another source of information, if any kind of action from the event were not included in the camera's field of view.

Microphones are used in conjunction with video surveillance devices are divided into two kinds, embedded and external.

• Built-in, integrated into the housing. This microphone is able to provide a basic sound quality, as the quality of his work affect the location of the camera (when mounted on outdoors extraneous noise will degrade the quality of the recording) and removal of the object from the sound recording (when installed in large indoor sound recording quality in the room is separated points low)
• External, which are connected to corresponding outputs of the camcorder. When using an external microphone, the microphone can pick up with predetermined characteristics, which may not be built in microphone. In addition, it is possible to install an external microphone at a distance from the camera, which will allow to choose a place to set up and get a higher quality sound when recording.

feedback speaker. Designed to organize two-way communication with the object on which the video camera. They are used in access control systems, CCTV, videoglazki and the outside panel.

P2P (Communication with your smartphone). P2P is also called "cloud", because the broadcast video stream with them is not on the DVR or video server, and Internet on a dedicated website from which the user can at any time see the video in recording or real-time time.

This type of connection demand in video surveillance, when installed on the remote sites. Costs for the installation of communication equipment by using P2P cameras are minimal-no need laying twisted pair or coaxial cable, do not need a DVR or video server and workstation operator.

Slot for memory cards. Many manufacturers equip the camera memory card slot. The standard form factor cards - SD or micro-SD. The advantage of the organization's records and reduced costs DVRs, video servers and wiring - ability to work offline.

Disadvantage - a small amount of video.

This method reduces the dubbing archive depth, ie the number of days of recording, are available for viewing. For this reason, memory cards with integrated cameras are used in the home or as a backup option using P2P technology or write to a remote DVR. Or where you only need short video fragments, for example, when an alarm sensor.

Widespread card received in devices called videolovushkami when the camcorder is mounted in places where difficult or excluded wiring, the use of wireless and GSM networks (in nature reserves, national parks, remote objects in a remote areas).

When using the recording only by the motion sensor, the archive depth reaches months (this parameter is determined by the size of the inserted memory card.)

Notification of movement. For notification in the surveillance camera motion corresponding to the motion sensor - a software module camcorder, DVR or video server. When you are in the frame motion sensor handles the event and performs programmed by an operator.

Warning about the movement may be as follows:

• Output to an alarm operator monitor. When the motion sensor monitor displays a picture with a corresponding chamber. The output image can be duplicated by an acoustic signal. At night, or when a significant number of cameras in the system, this method ensures that the operator or guard timely react to the movement in the frame.
• Sending of SMS notifications.
• Sending notifications by email.
• Sending notification to a remote server.

Support WDR. WDR (Wide Dynamic Range) is translated as "high dynamic range".

The essence of technology-saving high-quality images at any level of illumination differential. The most common example of a drop-light-illumination of the camera lens during the day due moving the sun hitting the individual image areas in the shadow of other bright light areas.

At the first frame, made with minimal exposure image does not manage to light up. In the second frame with the maximum exposure time to get into the lens image is very dark areas, then the processor combines the two into a single frame.

Frame obtained by processing the two previous ones, devoid of the disadvantages of each of them individually shaded areas become visible, lighted-contrast image suitable for viewing and analysis.

Distinguish between hardware and software implementation of the WDR. In the first case the matrix per frame makes scanning twice, with different exposures. In the second one and the same frame are used filters by changing the brightness and contrast is obtained a similar effect.

IR illumination. To give informative pictures cameras in low light conditions necessary illumination. Standard outdoor lighting incandescent lamps and fluorescent lamps are not everywhere, and, moreover, is not always controlled by the operator or guard.

In addition, the chamber with matrices operating in the "day" can be blinded by the directional light, street lighting can also be deliberately disabled. Infrared light is free of these drawbacks.

We consider in detail the principle of operation of IR illumination.

If a surveillance camera matrix has sensitivity in the infrared range (information about these properties of the matrix contained in the specification) with coverage area monitoring diodes in the infrared part of the spectrum, the matrix is ​​formed on the monochrome image, it is suitable for monitoring and analysis.

In this case, the visual observation area is not illuminated.

The basis of the IR LEDs lighting up the infrared spectrum that the human eye does not see.

For the implementation of IR illumination is divided into the following types:

• Built when the IR LEDs arranged in the camera body. It is important that the glass lens was separated from the glass covering the diodes backlight - this will eliminate exposure of the camera at night on the accumulated dust or condensation.
• External. Infrared lamps or spotlights, which are installed separately.

Supports ONVIF. Group standards for network cameras, videoristratorov, access controllers and other network equipment. Created in 2008 for the development and implementation of open standards for video surveillance systems.

Currently, the number of members of the ONVIF forum exceeded 600 companies. Using ONVIF protocols simplifies the integration of cameras from different manufacturers with DVRs, video servers and cloud services.

ONVIF standard defines the rules of interaction between transmitters and receivers.

A variable focal length. In use varifocal lenses called "Zoom". This ability to remove the lens or zoom observation object by moving the lens relative to each other within the lens barrel.

Lenses with variable focal length is called "varifocal". Varifocal lens can implement a more flexible setting of the frame without changing the camera position, zoom distant objects and to capture fine details.

The focal length of the lens manufacturer writes on the lens or the camera is pointing in the specification.

Keep in mind that the longer the focal length, the smaller the angle of the camera.

Anti-vandal protection. It is used in equipment to prevent injuries and damage caused by aggressive actions, and operation in harsh weather conditions.

Main place of installation of such cameras - areas with large crowds (railway stations, airports, public transport, parking and dimly lit tunnels, prisons).

Vandal design features reinforced bindings and hidden gasket communications, and high degree of protection against dust and flags. Wiring must be performed in a metal sleeve which is securely attached either be bricked up at the wall.

The lens is protected by a thick, compared with conventional camera glass or acrylic.

The preferred form of vandal-resistant dome and is considered the hemisphere. Due to the semi-circular body better able to withstand shocks.

When attaching the camera vandal important condition is the absence of fasteners and brackets. Blow stick or stone on fastening can not bring it down, but will break with the fastening. At the same time, the dome camera mounted on a wall, a stick or stone to slide without causing significant harm to them.

Antivanadalnye should distinguish between the case and the housing to the protection from dust and moisture. Any vandal proof camera will have a degree of protection against moisture and dust is not lower than IP67, but not with any degree of protection IP67 is vandal-proof.

frame resolution. Under the frame resolution taken to mean ratio of the height and width of the frame, expressed in pixels. Manufacturers of CCTV cameras following letter designations frame resolution adopted unchanged for different models.

• CIF, QVGA - 320x240
• VGA - 640 × 480
• SVGA -800h600
• WXGA- 1280x768
• SXGA- 1280x1024
• UXGA- 1600x1200

HD 1080 (full HD) - 1920x1080

The number of megapixels. Size, which determines the resolution of the matrix, i.e. the number of pixels per unit area of ​​the matrix. The greater the number of pixels, the more detailed image.

Benefits

crime prevention. Installing surveillance cameras reduces the number of petty thefts in public places and shops.

If the offense is committed, theft, car accident, the video will help to establish the chronology of events and participants. Recording with video cameras can be used when conducting investigations or trial.

Control and accounting. Many video surveillance systems equipped with modules, customer tracking, counting people in the queue, that It helps to keep statistics and to better organize the capacity of public places or trading point.

Control of personnel and protection of workers. When disputes arise, you can view the time interval of interest and resolve the contradictions.

disadvantages

Inability to one hundred percent coverage. Even if it seems supervision cover the whole territory, there might be blind spots or places where the video recording of not working effectively.

In addition, installing the cameras will not prevent penetration of the object or theft, but only fix the time and place and, if so configured, will alarm. Therefore can not be considered a guarantee of a video surveillance system from committing crimes.

The cost of the initial installation. Installing and configuring video surveillance system increases the expenditure item at the opening of a shop, a store or business.

Breach of confidentiality. Ongoing monitoring - psychological irritant that can perform the cause of loss of productivity of employees.

How to choose a CCTV camera

Before buying you need to clearly imagine requirements that apply to the video surveillance system.

Color or black and white? Cameras Black and white images have a higher compared with color sensitivity and low cost. The data, they have a serious drawback - the inability to accurately determine the color of the object. For example, orange and green on a machine chamber of black and white images are gray.

installation site (Outdoors or indoors). Whether heating and moisture protection is needed? whether it should be vandal-proof?

Ease of communication laying. Not whether there will be difficulties with the laying and installation? Is it possible to use the existing network in order to reduce costs? What is the magnitude of the costs for the installation of cables and installation of additional equipment?

If it is already laid, it will reduce costs and shorten the installation time.

How lit the place of installation. Required if the installation of IR illumination and an additional light, including infrared illuminators.

image detail. How clear picture or operators need protection? In observing the perimeter with a viewing angle of 90 degrees or more, and the distance to the subject is more than 20 meters, the camera with a resolution of 3 Mn is excessive, and suitable megapixel. If the observation is needed to distinguish the small details, those license plates, it is appropriate to establish a high-resolution camera with a viewing angle of less than 90 degrees.

The depth of the recording to the archive. Do I need a permanent record in the file, or only the frames are fixed when the motion sensor? Do your camcorder will keep a record of the archive? The answer to these questions will help in selecting the capacity of the DVR or video server.

Which is better

This question can not give a definite answer without knowing the specifics and requirements for the organization of specific surveillance systems. Each project video imposed specific functional requirements, on the basis of which is selected the best solution in this segment.

In developing these requirements must take into account the area of ​​the territory, the number of cameras and the installation location, the distance between devices, and many other factors.

If, for example, heating and a resolution of 2 megapixels will be the indisputable advantage when installing cameras on the street entrance of the plant, at the box office at the mall these characteristics are simply not needed.

Exploitation

Rules of operation of video surveillance devices are similar to the rules of operation of low-voltage equipment and network devices.

The main ones are:

• Avoid contact with the equipment to rain or jets of water, if the manufacturer's documentation expressly stated degree of protection against moisture and dust.
• If the equipment emits smoke or a strange smell, immediately stop operation of the equipment.
• When a fault is detected should immediately contact the service center.
• When cleaning the equipment can not use water, solvents and abrasives, which may damage the housing and lens glass.
• When installing video surveillance cameras should be, if possible, avoid installing them in direct sunlight, close to heating appliances.
• It is not recommended to install surveillance cameras in places of intense vibration, and in places with a strong magnetic field.
• When installing external video devices it is recommended to install lightning protection to reduce the risk of equipment failure during a thunderstorm. Thus Protector must be installed on both sides - on the side of the chamber and of the network equipment and necessarily grounded.

When checking the integrity of the enclosure is controlled by visual chambers, absence of cracks and dust on the lens, state of connecting wires, rasklyuchitelnyh boxes, signal connections, the voltage value when submitting power.

It also checks the operating status of network devices, lightning protection devices and backup power.

Guarantee

It is impossible to talk about guarantees in general, because the warranty terms and conditions depend on the policy of each company and may vary.

Standard is considered to be a guarantee of 12 months with the replacement of faulty equipment.

It extends not guarantee factory defects and failure of the device during the warranty period in compliance with the operating conditions and the absence of mechanical defects.

Faults and repairs

The video surveillance system consists of the following components:

• CCTV Cameras.
• Connection cables for which a signal is transmitted for processing operators.
• data processing equipment (DVR, video server, the operator monitor. )

When a fault occurs, you should first determine which component caused a failure in the system. Since the camera and networking equipment are technically complex devices, their self-repair tend to be difficult.

More often than not fail:

• The power supply (due to the surge, accelerations, substandard low quality)
• Matrix (because of leakage, constant exposure due illiterate installation)

Manufacturers of CCTV cameras

ActiveCam- brand DSSL Russian company. Specialization- surveillance. The company offers for sale a wide range of products for video surveillance:

• Analog external and internal execution, and the rotary chamber with infrared illumination.
• Networking of different types of performance, including anti-vandal.
• DVRs, calling the panel and video intercom.
• Camcorder Accessories, covers and mounting.
• A distinctive feature of the company - Issue of design cameras and the ability to order with your own design.

Altcam - budgetary surveillance cameras assembled in Russia from Chinese parts:

• network, analog external and internal performance, rotary, miniature, color and black-and-white camera and "day \ night."
• DVRs for analog video surveillance systems.
• infrared illuminators.
• own software for video recorders.

Standard company warranty is 12 months.

Axis - a recognized leader in the field of video surveillance. Produce high-quality CCTV cameras and accessories:

• web-camera.
• network and high-speed PTZ cameras.
• NVRs.
• video encoders.
• Accessories - mount housings, lenses.
• network devices
• control devices (joysticks and control panels)
• Specialized software for managing network cameras.
• IR backlight illuminators.

Standard Warranty 3years AXIS- Limited Warranty, which covers defects that have occurred in the manufacture, design flaws and low-quality material, which have been identified in the course of normal operation within 3 years from the time acquisition. Products with defects must be replaced or repaired free of charge to the customer.

Falcon Eye- a popular manufacturer of access control and video surveillance systems. Camera produces a budget and mid-price segment:

• analog external and internal execution.
• network of external and internal performance, high-speed rotary and vanadlozaschischennye camera.
• network equipment under its own brand.
• access control system.

The company provides a guarantee of 3 years.

BEWARD- manufacturer of equipment for professional videonablyudeniya.v company's product line includes systems:

• digital.
• analog.
• network equipment, sold under its own brand.
• DVRs.
• lenses.
• Lightning protection device and the surge protection.

The warranty period for equipment manufactured by «BEWARD» brand name is one year.

D-linkis an international company specializing in the production of network equipment. The product line d-link:

• network and wireless video cameras.
• NVRs and vidoservery.

The company provides resellers guarantee the return and exchange equipment diagnosed with workmanship.

Dahua-international company. Specialization - network and analogue cameras High Definition. The company's products are middle and professional segment of the equipment:

• network of external and internal performance, with vandal-resistant housing and the wireless camera.
• analog high-definition camera in the internal and external units.
• NVRs.
• analog recorders for high definition cameras.
• portable video recorders.
• camera explosion-proof.
• network equipment with PoE.

Hikvision - manufacturer of CCTV cameras and CCTV equipment from China. The company's product line includes:

• network and CCTV cameras.
• Analog videregistratory.
• Webcam with headset.
• DVRs.
• accessories (brackets, housings, the PoE equipment).

MicroDigital - South Korean company. Specialization - video surveillance. product line includes camera:

• Analog indoor and outdoor performance, including vandal housing.
• network of internal and external performance.
• network in the explosion-proof enclosure.
• lenses sold under its own brand.
• DVRs.

Ubiquiti - US technology company. Specialization - Wireless equipment level transmission companies and broadband providers.

The product line includes:

• network cameras indoor and outdoor performance.
• NVRs.
• networking and wireless equipment.

Vstarcam - the manufacturer of the line of budget camcorders of China. Specialization - small video surveillance systems for home and office.

The product line cheap wireless camera external and internal execution swivel. The company also produces P2P camera for convenient access to the video stream via the smartphone.

TP-LINK - an international company specializing in the production of network equipment in the budget segment.

The product line of low-cost wireless and web-camera, the scope of which a small-office and video surveillance at home.

Defender - an international company specializing in the production and sale of accessories for computer equipment. Video cameras are not a priority for the company.

In the line of products presented budget and wireless web-camera Full HD, The scope of which a small-office and video surveillance at home.

Ivue - Russian company that produces equipment under its own brand of Chinese parts. It provides a wide range of products in the low-end segment.