How Night Vision Cameras Work – A Look at 3 Technologies

How Night Vision Cameras Work – A Look at 3 Technologies

Alder Home Security offers a wide range of products to help families feel safer in their homes. Cameras are a cornerstone of home security systems, because they can provide protection during the day and at night, if they are equipped with night vision technology to see in the dark. Currently, Alder offers two cameras with night vision: the wireless doorbell camera and the wireless outdoor security camera.

Both cameras can help families rest assured that their homes are protected at all times of the day and night, whether they are at home or away. Night vision was a major step forward for the home security industry, and advances in technology make these cameras more affordable than ever before.

Three Different Approaches to Seeing at Night

Night vision cameras typically rely on one of three different technologies, each of which has its own benefits and drawbacks.



Thermal Imaging

Thermal imaging technology detects and displays the infrared radiation that all people, other living things, and objects naturally emit, due to their relative temperature. A thermal imaging camera does not need any ambient light to work. Instead, it uses the heat that radiates off people to create images of them. This technology shows heat as white and cold as black to form a sort of grayscale image. However, some cameras use colors to depict different heat intensities, and to help differentiate between different objectives even more effectively.

Thermal imagers work regardless of weather conditions, so they can continue to see in fog, smoke, haze, and other conditions. These types of cameras typically come in two different varieties. A cooled detector requires a vacuum-sealed case that is cooled cryogenically. However, an uncooled detector can operate at room temperature and thus costs significantly less. It can also produce high-contrast images of both people and vehicles.

Low-Light Imaging

Another way that security cameras work in the dark is through low-light imaging. Cameras with this technology have intensifiers that are sensitive to any available light and amplify it to improve vision. The objective lens on the camera focuses light to a photocathode, which triggers the release of an electron cloud that helps render the image when it strikes a green phosphor screen. The phosphor glows to reveal the image the camera has captured. Using green phosphor helps distinguish the image because human eyes can differentiate more shades of green than other colors.

Low-light imaging technology provides relatively good resolution at a low cost. With this camera, it is possible to identify faces. Low-light imaging cameras also consume relatively little power. At the same time, because these cameras work by amplifying existing light, they do not work in total darkness. In addition, very bright sources of light can damage the camera’s sensors.

Infrared imaging

Usually, infrared camera technology is paired with motion detectors. Once motion is detected, the camera turns on and illuminates the area with infrared light to make an image. This sort of light cannot be detected by human eyes. Two different types of infrared cameras exist. One type uses an infrared laser diode to create near infrared energy, while the other relies on an array of LEDs that emit infrared light. Because infrared imaging technology is so cost-efficient, it is often used in home security and perimeter protection.

One of the major benefits of infrared imaging is its ability to capture motion, even at high speeds. For example, these cameras can often catch the license plates of cars that pass by. The cameras automatically eliminate shadows to make objects, such as numbers and letters, appear much more distinct. In addition, infrared light can shine through fog, mist, and rain.

What Customers Need to Know about Night Vision Cameras

When planning out a security system, it’s important to understand a camera’s night vision technology and other important specifications, so you can see the strengths and limitations of the product. My company, Alder, sells a range of professional home security cameras that not only have night vision, but other features including motion tracking and audio.

For this reason, you should also be familiar with the lux rating of the camera. Lux is a measure of the amount of light in a given area; a lux rating on a camera is a measure of how sensitive the camera is to light. In a sense, a lower lux rating is better—it means the camera can produce an image even in very low light—but lower lux numbers may come with some trade-offs in terms of image quality. Ultimately, you should discuss all your options with a professional installer, like Alder, and collaboratively formulate a plan.

When planning a system, it’s also important to think critically about weak points and address them. Ideally, your cameras should be placed so that there are no blind spots that could be taken advantage of, especially in the dark. For that reason, it’s also important to understand the night vision range of any camera you’re considering.

You should also pay attention to how and when the camera system records, as well as the means through which you can access it. Alder’s wireless cameras can be accessed anytime, from anywhere in the world with an Internet connection via live stream. In addition, the Alder app gives customers instant access to any previously recorded video. Learn more about night vision cameras online at