Video surveillance is one of the best ways to secure your property. But in order to understand all the nuances of the modern market for video cameras and find the right model, you need to understand the features of their device.
The camera is only part of the video surveillance system. The main criteria by which it must be selected are:
- degree of protection of the case from external influences;
- viewing angle;
- image quality;
- type of data transfer and storage;
- price.
Main characteristics
Installation
A street video camera, in contrast to an outdoor one, requires reliable resistance to external weather conditions. In our climate, this is resistance to wind, rain, snow, and icing. Therefore, you need to choose a camera taking into account the temperature range in which it can work.
Without good weather protection, the camcorder will not last long
A video camera located outside requires a reliable sealed enclosure, which can be equipped with a housing that warms it. If you need to survey an unfavorable area, anti-vandal protection will not hurt. However, the latter can often be solved by installing the camera in an inaccessible place where hooligans will not reach: for example, at high altitude.
Most often, manufacturers equip camcorder models with casings that initially provide protection against wind and moisture. Their purchase will cost less than self-assembly of a protective casing from separately purchased materials.
Housing
The main types of cameras by their form factor:
- Dome video camera - has the shape of a hemisphere, used both indoors and outdoors;
- cabinet - mounted in a housing without brackets or other fasteners, for self-installation;
- modular - it is delivered in the form of equipment without a case, for specialists;
- miniature - designed for covert video surveillance, valuable in size, but poorly protected from external influences and is not famous for good image quality;
- street - is hidden in a reliable case with heat and moisture protection, most often dome or cylindrical;
- camera of any shape, equipped with a rotary mechanism.
Dome Camera - The device is hidden behind a transparent glass
Overview
camcorders, there are two main types of review: fixed and variable (in the language of experts - varifocal). Outdoor cameras with varifocal viewing angle will cost much more.
Among the models with a fixed overview, there are:
- cameras with a view of up to 45 degrees, suitable for monitoring a small area;
- with a view of up to 90 degrees, covering a wider area;
- panoramic cameras with a viewing angle of more than 90 degrees, which are of little use for portraiture, but "see" everything around them.
The smaller the viewing angle of the camera, the more likely it is that all the small details will be displayed in the image received from it with an increase. So, panoramic cameras often “sin” by the fact that remote peripheral objects are poorly displayed. A rotary street camera with a small viewing angle is spared from such drawbacks, although it is not suitable for simultaneous monitoring of the entire area.
Panoramic camera distorts peripheral areas
Picture
High-resolution cameras are primarily needed for monitoring large areas and far-flung objects, as well as for detailed shooting.
Analog cameras have long been replaced by digital equipment, the resolution of which is determined in pixels. If 1 megapixel is enough to monitor the room (1 megapixel will give a picture with a resolution of 1280x720 pixels), then for panoramic shooting you will have to fork out for a camera that gives a signal of 4 megapixels.
The resolution with which the camera shoots is not always decisive for image quality. It will depend on the quality of the entire video surveillance system as a whole - wire connections, software, equipment settings.
And one more non-obvious point: cameras that shoot black and white images should not be perceived as cheap. Monochrome recording provides much better performance in different lighting conditions than color.
Let an image be better than just a black screen
Illumination
Light levels directly affect image quality. The camcorder reacts to changes in lighting either with the electronic shutter (almost like in a conventional digital camera), or by changing the diameter of the aperture.
Aperture devices are much better at adjusting the image because they respond more quickly to an increase or decrease in luminous flux. An outdoor camcorder equipped with a shutter takes time to adapt, and when changing lighting, the image received from it may be darkened or blurry. If video surveillance is mounted on an important object, you can not do without a diaphragm.
At a low level of illumination and when it is impossible to equip an object with artificial lighting, infrared sensors are used. Video cameras with IR illumination produce a black and white image, but they work even in complete darkness. When choosing a monochrome model, it is necessary to clarify the power of the LEDs built into it, so that infrared lighting is enough for the entire observed area.
Dear models are equipped with two matrices for b / w and color images, but this is not the most popular option precisely because of their high price.
Motion Sensor
An extremely useful option that performs two useful functions at once:
- increases the chance to capture uninvited guests;
- It allows you to save space on your hard drive during inactive operation (that is, when the camera is turned on only by a sensor signal).
The camera can monitor the special area after setting
The motion detector can be installed both on the camera itself and in the form of software on a computer. Its work is almost invisible to the server, so for home use it does not matter which option to choose. If the guarded object is large, and there are many sensors, it is better to choose cameras with built-in detectors in order to avoid unnecessary loads on the network intended for the video surveillance system.
Signal transmission
Analogue and digit
Analog camcorders transmit the signal to the equipment in PAL or NTSC mode. This signal must first get to the recording device, and only then the data from the camera can be copied to the hard drive.
Digital equipment will automatically transfer the digitized data directly to disk. It can also work on a wireless wi-fi network, which is especially convenient: it allows you to do without laying extra wires. Again, if there are a lot of cameras at the facility, the traffic they consume can affect the speed of the Internet, which should be taken into account beforehand. But such a data transfer will save even from a source of electromagnetic noise, with which attackers can try to drown out video surveillance.
Analog signal transmission has its advantages:
- analog cameras are usually cheaper;
- such a signal can be sent over old wires without a complete update of the video surveillance system;
- analog data is transmitted without the delays sometimes experienced by digital systems.
But compared with the capabilities of digital equipment, these advantages are invisible. In any case, the “figure” will give the best picture resolution and is less dependent on the quality of the cables.
Antenna eliminates wires
Mobile networks
Some camcorders connect to cellular networks, transmitting data over them in the same way as mobile phones. Today, cellular networks are almost everywhere, and this connection option is becoming more convenient.
Its main advantage is the ability to receive a video stream from cameras in online mode even through your own phone, while being anywhere you want. Most models will allow you to quickly get photos from the protected area by SMS request, and can also notify via SMS that movement has been detected at the object (if there is an appropriate detector).
To make such a connection, you need to select a camera with a SIM card slot, in the future you only need to pay for the connection and periodically check the electrical networks leading to the camera. No more wires needed.
It’s just nowhere more convenient
Data storage
Most often, the signal from the cameras is stored on the hard drive (through decoders or recorders for systems with analog equipment). Over time, video archives grow to exorbitant sizes, but this problem has a solution.
If the video surveillance system operates on the signal of the motion sensor, then the recording will not be wasted. Only those moments will be preserved during which some action was detected on the observed area. The amount of data in such a system is reduced to a minimum, while you can do without a hard drive at all, having acquired a camera with data recording on a memory card.
Webcams are devices that transmit data directly to the Internet. This method of storing information does not bind the employees of the surveillance system to a specific place, it frees from the risks associated with the destruction of the hard drive. However, you will also have to pay for a large place on the cloud server, because over time, cameras will produce a huge amount of video data. How much time to store them - everyone decides on the basis of their own needs.
How to choose the right model
The main advice: do not complicate your own life
- Decide on the purpose of the purchase to meet the budget. A large territory will require the installation of several outdoor video cameras, as well as their competent integration into a single system. And, for example, under the visor of the entrance, it is quite possible to install an inexpensive, but inconspicuous model, albeit with an analog signal.
- Think over the requirements for image quality: do you need a 4 megapixel picture, does it make sense to set infrared illumination, will panoramic shooting be required? Additional features, including a motion sensor, can be expensive and unnecessary.
- Select the type of signal transmission - analog or digital, with a connection to a hard disk or recording to a memory card, with a connection to an Internet cloud or with data transmission over a cellular network. Sometimes it’s better to get around cabling.
Price tag
Consider five top models from various manufacturers, popular in Russia in 2018 (prices are for the summer period). These professional street camcorders have earned a good reputation and justify their cost with quality work.
Hikvision DS-2CD2055FWD-I
This cylindrical camera gives a picture of the highest resolution (5 megapixels), has several modes of operation for different external conditions, is capable of recording on a memory card. It is distinguished by the ability to analyze what is happening in the frame, counting objects, monitoring the intersection of the specified zone and instantly reacting even to changes in sound.
Such a model will cost 12,000 rubles.
Dahua SD22204T-GN
A dome camera with a fast pivot mechanism that can be programmed for a specific nature of patrolling the area.Equipped with 16x zoom with high-quality zoom. The only negative is the lack of infrared illumination.
Price - 12 790 rubles.
Zodikam 2051 (205)
A camcorder designed to transmit data over a cellular network. It has a small resolution (1.3 megapixels), but it confidently supports 4G communication and is easily compatible with most mobile devices. It works both with a motion detector and in continuous mode, but in the case of continuous recording, you will have to take care of an unlimited communication tariff.
This camera costs 14,950 rubles.
HiWatch DS-I200
A cylindrical camera for a budget approach to video surveillance. It does not support memory cards, but it works fine in low light, giving a picture of up to 2 megapixels, and is equipped with a powerful LED.
You can buy this for 7 690 rubles.
EZVIZ Mini Pano
A dome camera specially designed for panoramic shooting: in an open area, you can not even duplicate it. Included is a high-speed module for wi-fi connection and infrared illumination.
Price - 11 690 rubles.
