Night surveillance outdoor cameras are the best choice for objects that should be monitored around the clock. Such devices are divided into several types depending on the connection method, additional options and other features. Before buying, it is worthwhile to study in advance the rules for the use and installation of these devices, selection criteria and other important nuances.
Device and principle of operation
A standard camcorder with the option of tracking in the dark has a simple design consisting of a microcircuit, a lens, sensors, an arm and a housing. The main feature of these devices is the presence of IR illumination, which is responsible for the organization of control in conditions of poor visibility. They work according to the usual scheme, during the day the matrix of such cameras receives UV radiation, which changes to infrared at night, while the device itself begins to transmit a black and white image.
The range of their functioning can be 715, 850 or 940 nm. Since the human eye is not able to distinguish between radiation with a wavelength of more than 780 nm, manufacturers produce devices with indicators of 850 or 940 nm. The rest of the night camera is practically no different from its classic counterparts. Most often, such devices are equipped with large-sized cases, and also have an increased level of energy consumption, requiring the use of powerful autonomous power sources or connecting transformers.
All night vision cameras are supplemented by built-in light sensors that can automatically detect the moment at which the light flux becomes insufficient to ensure high quality shooting.
Main characteristics
A street surveillance camera with night vision should meet the basic requirements, the main of which is the remoteness of object detection. The parameter determines at what distance the broadcast of the image will be most clear. Also, the range will depend on the power of the light flux and the sensitivity of the matrix. When choosing, you need to consider adaptability and the angle of the backlight: the wider it is, the less distortion will be in the process. Also pay attention to power and energy consumption, these characteristics are important when connecting equipment. To ensure a visibility range of up to 10 meters, you will need a backlight of 5-10 W, capable of consuming at least 1 A of current.
A prerequisite for the night tracking device is the presence of the day / night option. It ensures optimal image quality in the presence of natural light. The acceptable sensitivity of the matrix should be at least 0.001 lux, only in this case you can get a high-quality picture in the dark. The surveillance video camera should also have an ICR filter that cuts off the IR filter during the day and prevents image distortion or blurring. It is better to choose devices with a waterproof case (according to the standard not lower than IP65) with a thermal cover that withstands the effects of condensation and temperature extremes.
Varieties of outdoor CCTV cameras
With night vision
Video recorders at night can be analog or digital.The first type of device is suitable for small video surveillance systems and works on the principle of converting the light flux into electrical signals that are transmitted to the server or displayed on the monitor. Digital cameras are capable of solving a wider range of tasks; during their operation, light fluxes turn into digital ones due to the built-in encoder with a matrix. They can be combined into video complexes with a large number of devices.
Wifi camera
Wi-Fi devices are supplemented by a CMOS matrix, a recorder and a processor for data compression. Data during the operation of such cameras is transmitted via digital channels using Ethernet and TokenRing networks via IP data protocols. The way they function resembles computer systems that use local networks, routers, and routers. Each device has its own IP address and transmits audio and video signals, compressing information using video codecs, which are then recorded on a registrar, connected computer or cloud service.
With recording system
Cameras with a built-in recorder and the ability to record to a USB flash drive are IP devices that can only be standalone or transmit signals via Wi-Fi or GSM. To view the video archive, you need to remove the memory card and insert it into a laptop or computer equipped with a USB port. Such devices are powered by a battery or battery, so this type of camcorder can be installed hidden.
With motion sensor
A camera for night vision with a motion sensor is able to quickly respond to the slightest activity in the zone of the controlled territory. Additionally, in some devices of this type, the mode of recording and sending notifications to the user's phone can be immediately activated. These devices are often included in alarm systems, during which they activate siren signals.
Other species
In addition to the described types, there are other types of cameras for night tracking, the list of the most popular includes radio and 3G devices. The devices of the first type consist of recording elements, a DVR and a radio receiver. The signals from the camera are transmitted to the receiver due to radio waves, which allows us to limit ourselves only to connecting the device to power. 3G models work on the technology of high-speed signal transmission from the device to the Internet. Their main advantages are broadband access to the network and the ability to transmit data at any distance.
Criterias of choice
To choose a high-quality camera for the street, which can be used on a private, commercial or industrial facility, you will need to take into account the technical requirements for the devices:
- high level of fault tolerance, quality of housing materials and life;
- resistance to aggressive environmental influences, the presence of visors and protective covers;
- the ability to work in various lighting and at any time of the day.
Outdoor devices for homes and businesses must comply with safety conditions, which are the same regardless of where the cameras will be installed.
Features of CCTV cameras for night vision
Cameras for shooting in the dark have their own characteristics that are characteristic only for devices of this type.
Particles of dust, snow or raindrops that fall into the field of view of the lens at night are able to reflect IR illumination and interfere with image perception. After that, it becomes almost impossible to recognize anything on the screen. Such interference can be observed only during a strong snowstorm or rain.
Image ripple when working with unstable energy sources most often occurs due to the difference between the recording speed of the camera and the frequency of the pulsating backlight. This factor negatively affects the stability of the tracking device.
The life of the backlight diodes in night cameras has limitations in the range from 20,000 to 50,000 hours. If this option works 12 hours a day, its service life can be 5-10 years, then the LEDs will need to be replaced or other light sources used.
Popular camera models
Among the large number of outdoor cameras with night vision option, several of the most famous models are distinguished.
The 2-megapixel IVUE NW451-PT device with a backlight distance of up to 30-40 meters operates at a temperature of -30 to +55 degrees, supplemented by a built-in ICR filter and the WDR function against backlighting.
Also no less famous are devices from the Vumii brand, which belong to the category of devices of a professional level, capable of recognizing objects at distances of up to 200-400 meters thanks to 120x zoom.
