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How does night vision security camera work?

by | Apr 9, 2018 | Learn

A security camera system is an important part of protecting your property, whether home or business. It’s crucial to install night vision cameras that can capture high-resolution images even in near-total darkness. Intruders generally prefer to operate at night, so it’s important to have clear footage both to monitor your property and to follow up with law enforcement.

I also recommend you to check our two guides that will help you in choosing the best system that fits your needs:
Security Camera System Buyer Guide & Important Features for Security Camera.

There are two basic types of night vision security camera: infrared and light amplification.

 

– Infrared Cameras

Infrared (IR) light is a form of energy within the electromagnetic spectrum, like other light. Though it’s closest to red light, IR wavelengths are invisible to human eyes. The most common source of IR is heat, such as the warmth produced by living bodies. Instruments can determine the temperature being given off by comparing the amounts of IR detected.

Infrared cameras are designed to detect this infrared light, or radiant heat, and use it to reconstruct visual images. The process is called thermal imaging. These images can be saved and viewed like any others.

– Light Amplification

This type of camera can amplify any available light, whether it’s the light of the stars or distant streetlights. Some cameras can also utilize invisible light such as infrared rays and amplify this, as well. Night vision security cameras are able to enhance the light by using chemicals that are very light-sensitive. Light, actually a stream of photons, passes through a vacuum tube or series of tubes to strike the photosensitive material. The electro-mechanical component within the camera, known as a microchannel plate, can translate this detected light into the image you see. This image is not visible without the camera, but is created artificially within the device. The light resolution of the image can be of such fine detail that it’s measured in ppm (parts per million).

The quality of images has improved over time as better chemicals and better electronics appear. This is often referred to in terms of generation (generation 1, 2 3, etc.), although generation 4 is still largely on the drawing boards. Some of the technology used now, however, can actually amplify ambient light even in the darkness to the point where it’s blinding to the human eye.

You’ll also find many security camera products that are designed as day/night systems, meaning they can be tripped by a light sensor to go into night vision mode after dark or when interior lighting is turned off. 

Storing Video

As technology improves, modern surveillance systems can store impressive amounts of video using a DVR or computer hard drive. Digital image files are also much easier to manage and review using the right software, such as facial recognition programs. Most systems will allow you to record from multiple cameras simultaneously. 

A good surveillance system can provide continual recording, be programmed to record only for certain time periods, or at intervals of a few seconds throughout the night. Others may work with motion detectors so that they’re activated only when intruders are detected.

What to Look For

Be sure your new system can handle the number of cameras you need or is easily expanded. How the cameras are connected is also important. Wired surveillance cameras may be suitable for a few cameras covering a limited space. For larger installations, you’ll probably want to use Wi-Fi devices that can be added to a wireless network and managed through a router. You might also want an IP (internet protocol) system if you want to be able to view save, or share live images over the internet.

You can buy cameras that show either black and white or color images. Color cameras are able to accurately reproduce various tones such as clothing or hair color using electronic color filters.

Security cameras for outdoor use should be designed specifically to resist the elements. They should be rated as waterproof and dustproof and able to function in sub-zero temperatures.

Lux is a measure of brightness. A lux rating in cameras refers to the lowest level of light at which the device can form a picture. Even some older black and white cameras have lux ratings as low as .0003. A full moon, by contrast, gives off about .27 lux. With lower quality cameras, however, the images produced tend to contain a lot of signal static.

There are two great security camera systems that we always recommend to our private customers who are looking to take their first step in securing their property, it is the Amcrest 960h and the Reolink RLK8-410B4.

At a minimum you should have cameras covering the front and rear of your home. On a commercial property you might also want cameras covering the lobby, expensive inventory, gates, fence perimeters, and any external blind spots. The best part of today’s surveillance cameras is that you can usually add more to your system as needed. But, as even the presence of cameras can deter intruders, having them in place will more than justify the expense.