Today, numerous night vision cameras are being offered to consumers. But, have you ever wondered and asked: “Why do night vision cameras use infrared detectors?” “What are the mechanisms involved in the technology of these little monsters?”
Read on to find out the secret that lies behind these amazing tools to give the best possible images!
Take a look at your security camera, and you will notice that it is covered with multiple tiny LED bulbs. These small yet powerful bulbs are the infrared lights. Once it gets dark outside, these lights will turn on and automatically flood light of sorts in order to capture images.
The infrared light is completely invisible to the naked eye. Thus, you don’t really see a bright light, but instead, the camera sees it.
The footages produced by the infrared night vision cameras https://nvrig.com/ always look black and white. This is primarily because the human eyes can differentiate the black-and-white color a lot better than they can with other shades or colors. Thus, most night vision cameras switch the footages to a monochrome filter, making it easier to see.
The night vision camera that uses infrared technology comes with an infrared cut filter. This helps detect the daylight, ensuring that the infrared light is blocked and that the colors look real.
During night time, the filter will then automatically be removed to allow the infrared lights to do their job. The three different types of infrared light are as follows:
Infrared spectrum comes in different wavelengths including shortwave, medium wave, and long wave. The radiation emitted by the wavelengths is detected using several infrared detectors. Infrared detector usually reacts with the infrared radiation, and it has two main types namely thermal and direct detection.
This can either be photoconductive or photovoltaic. Both require intense cooling systems for better performance in photon detection.
The photoconductive night vision camera utilizes the components that can change the electrical resistance when the photons strike at a specific wavelength. On the other hand, photovoltaic types are sensitive to photons, making them change their voltage instead of changing resistance.
These types of cameras are a bit pricey and are more prone to expensive repairs. The lack of integrated cooling systems gives less precision than cooled counterparts.
This is often integrated with microbolometers since they don’t detect photons. Instead, they pick up the temperature differences by simply sensing the thermal radiation based on a distant object.
Once these microbolometers absorb the energy, the sensor of the detector will have an increase in temperature. In turn, this alters the resistance present on the sensor material. With the help of a processor, the changes that occur will be interpreted and be used to generate an image for display.
This type of detector doesn’t require the use of any cooling system. Thus, it comes in smaller yet integrated sizes.
The thermal images https://nvrig.com/night-vision-goggles-guide/#tab-con-4 works just like how the eyes work. The only difference is that instead of picking up visible light, the thermal technology detects the heat present and released in the object.
Both hot and cold objects emit heat. The heat emitted moves out until an imaging device can detect and see it. This device comes with an optical lens that focuses the energy released into an infrared detector. The detector comes with thousands of data points which are detected by sudden changes in temperature.
After which, the detector will construct a thermogram or a temperature pattern. The data gathered are then transformed into electrical signals and kept in the camera’s processing chip. This chip will then convert the raw data into visual signals that appear as images on the screen.
The entire process of thermal imaging works very quick, usually at a rate of 30 times per second.
The visual details of the objects usually vary depending on the relative warmth of the object in view. Less distinct temperature gradations tend to produce fuzzier and less definitive images while more striking details are produced from distinct gradations.
The picture quality also changes depending on the imager, whether active or passive. Active systems add warmth to the surface of the target object, and they usually use laser and other energy sources to promote more visibility to the infrared detectors. Passive systems detect the objects heat depending on their natural emission.
The thermal imagers continually improve the sensitivity and features of the images produced. However, they are still not perfect technology and may sometime experience troubles and difficulties.
With the vast array of available models and a good number of considerations in buying a night vision device, the most important things to consider are as follows:
Before choosing an infrared night vision camera, it is important to familiarize yourself with the different types of infrared detectors, camera specifications, and how these features can affect the performance of the system. Know how these little wonders work and why do night vision cameras use infrared detectors. Doing so will not only allow you to pick the best and most appropriate camera but also gives a better knowledge of these amazing gadgets for future references.