Security cameras are a great way to protect your family, business, and property from invaders because protecting your family and property is the top-most priority.
Nowadays, most security cameras come with night vision technology. The night vision allows them to see things in pitch-black environments.
As we all know that humans are diurnal, which means living in the daytime and sleeping at night time.
Moreover, our eyes can’t see through the complete darkness, but the night vision security cameras enable us to see in the dark. The reason behind this that the night vision camera floods the area with infrared light.
These infrared lights are a type of electromagnetic radiation with longer wavelengths, so the human eyes can’t be able to detect the invisible light, but only the camera lens can.
Many different types of night vision cameras are available in the market and they are great for providing standard security.
In this article, we will let you know How Does the Night Vision Camera Work? and the techniques used for capturing and recording video footage in the dark.
What is a Night Vision Camera?
A night vision camera is an optoelectronic device that can monitor in low light to completely dark environments.
The captured images are a combination of infrared and visible light. These cameras are popularly used by law enforcement agencies, but they have improved in the decade, and now it has been widely used among civilians too.
To protect the cameras from the rain, these night vision cameras have equipped with a water-resistant casing and an image intensifier tube.
Most night vision cameras use one of these three methods to capture images in dim light or pitch-black situations. Before jumping into this, let us know how night vision cameras work.
How Does the Night Vision Camera Work?
Night vision cameras use infrared light to illuminate the images in the darkness.
Infrared light is all around us but we can’t see it. But, these night vision cameras detect those invisible IR wavelengths, thus it enables the security cameras to see in the dark.
These night-vision cameras rely on integrated technology, but most night vision cameras use sensors and lights.
Night vision cameras work in two different ways, one uses an active night vision system, and the other uses a passive night vision system.
The active night vision system uses infrared light to illuminate the images in the dark.
This infrared light is invisible to the human eye, but the night vision cameras detect this invisible IR light. Thus it enables the camera to see in the dark.
To amplify the existing light, the passive night vision system uses an image intensifier tube.
This passive IR light converts low-level lights into electrons. Thus, the electrons are accelerated and producing more visible light.
Have You Ever Noticed the Security Camera?
It will be covered with small LED bulbs. These LED lights are responsible for projecting IR light, and it acts as a source of light to the security cameras.
They transmit IR light at night-time or whenever the camera switches to the night mode. But, these infrared lights are invisible to the human eye.
The video footage from the night vision security cameras always looks black and white, because our eyes can easily differentiate between black and white color rather than any other shades of colors like red or blue.
That’s why most of the night vision surveillance cameras switch to monochrome filters, making it easier for us to see the images.
To block IR light during the daytime, most night vision cameras come with IR cut filters.
This filter is placed between the sensor and the camera’s lens. In the daytime, IR cut filter allows the visible light and purposely blocks out the infrared wavelengths, as it could affect the image quality.
This filter automatically gets removed when the nighttime arrives and allows more Infrared light in, including the IR light from the camera.
This process is known as TDN (True Day Night) as it delivers the true color images during the daytime and black and white images during the night-time.
Do you know how these night vision surveillance cameras work in complete darkness? It works under three different methods and they are,
Low Light Imaging
This technology is used to improve visibility in low-light environments. Moreover, the low-light imaging cameras work by using image intensifiers to amplify the available light.
This image intensification technology works by collecting the available light through an objective lens and converts them into electrons through the photocathode of an image intensifier.
The photocathode is an electrode made from photoemissive material that converts electrons via the photoelectric effect.
The electrons are then released by the cathode and are accelerated by an electric field.
The accelerated electrons enter through the holes in the microchannel plate and strike on the channel walls, resulting in creating more electrons as they bounce through.
When these electrons strike the phosphor screen to make the phosphor glow. The phosphor screen emits this light in the same pattern as the light collected through the objective lens.
Finally, a brightened light displays the desired view to the user, or an intensified image is seen through the eyepiece.
Thus, these low-light imaging methods use image intensifiers to create clear images during low-light conditions.
Benefits of Low-light cameras
- It can identify people in dim-light
- Low-light cameras are the popular choice among house owners as they are cost-effective.
- The Low-light night vision cameras are the only security cameras that have been producing a colored image in low-light situations.
Pros
- Works well in low-light conditions
- Affordable
- Low power consumption
Cons
- Do not work in pitch-black situations
Infrared Night vision
Night vision Security cameras utilize infrared illumination and motion detection technology for delivering effective night surveillance.
These cameras detect the movements, the IR illumination lights up and the captures image.
It works with multiple LEDs to produce excellent black and white images and videos. Unlike the low-light imaging cameras, the IR night vision cameras have the possibility of recording in complete dark situations without any additional light sources. Moreover, they can provide visibility in fog, mist, and rain.
Well, what’s infrared illumination, and how does it work? Now we will look at how infrared illumination works.
An infrared illuminator is a device that emits light in the infrared spectrum. This infrared radiation is also called infrared light and it functions as a flashlight.
The IR illuminator included in the night vision camera is an infrared LED that emits light in the infrared band.
The reflected light is then collected by the camera lens. This infrared light has a longer wavelength than visible light, and it can be experienced as heat.
An infrared camera is used to detect the heat emitted by the observed scene and convert it into an electronic signal. Infrared light is invisible to the naked eye, but not to the night vision cameras.
For this reason, infrared night vision cameras are not preferred by the military and covert operations even though maybe needful for sighting targets and navigating in the complete darkness.
Benefits of an Infrared illumination Night vision camera
- They use LED lights that last longer than normal light bulbs and use less power.
- Provides better illumination in hazy conditions.
- Records clear surveillance footage both day and night.
- Reduces glare from the vehicle headlights or street lights so nothing will obstruct your video footage.
Pros
- Great for security purposes
- Works well for target recognition
- They are not affected by any surrounding lights
Cons
- Expensive
Thermal Imaging
Thermal imaging technology uses heat that objects give off instead of light sources to produce images. These cameras work by detecting tiny differences in temperature and capturing different levels of infrared light.
This infrared light is invisible to the human eye, but it can be felt as heat. The higher the temperature of an object that emits more infrared radiation.
It’s similar to the type of energy, but it has a slightly longer wavelength. Then this infrared radiation is converted into a visible image.
Many thermal imaging cameras are available in the market, and they are used for projecting images in different colors.
If the object is hot, it produces the images in the shades of blue, green, or purple color, and if the object is cold, it produces the images in the shades of red, yellow, and orange, while other areas with the shades of purple and blue.
The thermal cameras allow the users to detect any objects that radiate heat at great distances. Furthermore, it allows visibility even in the complete darkness, stormy, foggy, and very poor weather conditions.
Benefits of the Thermal Night Vision Camera
- It can see over much longer distances, rather than a typical night vision camera.
- Offers very good visual contrast, and it’s easier to detect.
Conclusion
Hope this article will greatly help you to know How Does the Night Vision Camera Work? and the methods used. Moreover, these night vision cameras are great and complex tools to do night vision surveillance in a peculiar spot. Hence, various technologies have been employed in the advancement of night vision cameras. You have to choose the right one that you are going to be used for your needs.