Outdoor night surveillance cameras are the best choice for objects that must 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 video camera with a dark tracking option has a simple design consisting of a chip, lens, sensors, bracket, and housing. The main feature of these devices is the presence of IR illumination, which is responsible for organizing control in poor visibility conditions. They work according to the usual scheme, during the day the matrix of such cameras perceives UV radiation, which changes to infrared at night, while the device itself begins to broadcast 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 practically does not differ 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 supplies or the connection of transformers.
All night vision cameras are supplemented with built-in light sensors that can automatically detect the moment at which the light intensity becomes insufficient to ensure high quality shooting.
Main characteristics
An outdoor CCTV camera with night vision must meet the basic requirements, the main of which is the distance of object detection. The parameter determines at what distance the image will be broadcast most clearly. Also, the range will depend on the power of the light flux and the sensitivity of the matrix. When choosing, you need to take into account the adaptability and the backlight angle: the wider it is, the less distortion will be during operation. They also pay attention to power and energy consumption, these characteristics matter when connecting equipment. To provide a visibility range of up to 10 meters, you will need a 5-10 W backlight capable of consuming at least 1 A of current.
A prerequisite for a night tracking device is the presence of a day / night option. This ensures optimal image quality in the presence of natural light. Acceptable matrix sensitivity 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 must also have an ICR filter, which cuts off the IR filter during the day and prevents distortion or blurring of images. It is better to choose devices with a waterproof case (according to the standard not lower than IP65) with a thermal casing that can withstand the effects of condensation and temperature extremes.
Varieties of outdoor surveillance cameras
With night vision
Night video recording devices can be analog or digital.Devices of the first type are suitable for small video surveillance systems and work on the principle of converting the luminous 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, the light fluxes are converted 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 cameras
With recording system
Cameras with a built-in recorder and the ability to record on a USB flash drive are IP devices that can only be stand-alone or transmit signals via Wi-Fi or GSM channels. To view the video archive, you need to pull out the memory card and insert it into a laptop or computer equipped with a USB port. These devices are powered by a battery or rechargeable 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 controlled area. Additionally, in some devices of this type, the recording mode 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 types
In addition to the types described, there are other types of cameras for night monitoring, the list of the most popular includes radio channel and 3G devices. Devices of the first type consist of recording elements, a video recorder and a radio receiver. Signals from the camera are transmitted to the receiver using radio waves, which allows you to limit yourself only to connecting the device to the power supply. 3G models operate 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 transfer data over any distance.
Criterias of choice
To choose a high-quality outdoor camera that can be used in 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 body materials and service life;
- resistance to aggressive environmental influences, the presence of visors and protective covers;
- the ability to work in various lighting conditions and at any time of the day.
Outdoor devices for homes and businesses must meet security conditions that are the same no matter where the cameras are installed.
Features of CCTV Cameras for Night Vision
Particles of dust, snow, or raindrops that enter the lens's field of view at night can reflect IR illumination and interfere with image readability. After that, it becomes almost impossible to recognize anything on the screen. Such interference can only be observed during a severe blizzard or rainstorm.
Image ripple when working with unstable energy sources is most often caused by the difference between the camera's recording speed and the frequency of the pulsed backlight. This factor negatively affects the stability of the tracking device.
The service life of backlight diodes in night cameras is limited 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 the option of night vision, several of the most famous models stand out.
The 2-megapixel device IVUE NW451-PT with a backlight distance of up to 30-40 meters operates at temperatures from -30 to +55 degrees, supplemented by a built-in ICR filter and WDR anti-backlight function.
Also known are devices from the Vumii brand, belonging to the category of professional-level devices, capable of recognizing objects at distances of up to 200-400 meters thanks to a 120x zoom.
