Night vision technology has become an essential tool for various industries, especially in security and surveillance.
Whether you’re monitoring a remote perimeter, a warehouse, or a residential property, night vision ensures visibility even in total darkness.
But have you ever wondered, how does night vision work? What scientific principles power this groundbreaking technology, and how does it benefit industries relying on video monitoring?
This blog gives you the science behind night vision, explores its various types, and offers insights on how it can enhance security systems. Plus, we’ll offer practical tips on what to look for in night vision cameras and outline the industries that benefit most from this cutting-edge technology.
What is night vision?
Night vision works by detecting and enhancing available light, especially infrared light, which is abundant at night but invisible to the human eye.
The above graph shows that while human eyes see best in visible light (peaking around green), night vision goggles—especially Gen III models—are designed to capture more infrared light.
Since most of the light from the night sky falls in the infrared range, advanced night vision technology allows us to see clearly in the dark by converting that invisible light into a visible image.
Different types of night vision instruments.
1. Night vision goggles (NVGs).
Night vision goggles (NVGs) are simple in concept, but people overcomplicate them. You’ve got two parts: the housing (the outer shell with a name like PVS-14 or GPNVG-18) and the tube inside (the real MVP that actually amplifies light). Most people confuse the “generation” with the housing.
Gen 1 → Cheap. Civilian-grade. Needs IR light to work (which makes you visible to better NVGs).
Gen 2 → Middle ground. Takes ambient light and boosts it—usable for civilians and military.
Gen 3 → The gold standard. Better clarity, better light amplification, and advanced tech like white phosphor and autogating.
2. Night vision scopes:
Rifle-mounted or standalone optics that enhance vision for shooting in darkness. They have three basic components:
- an objective lens system.
- an image intensifier.
- an eye lens system.
3. Night vision monoculars:
Small, single-lens night vision devices, ideal for portable use.
4. Night vision binoculars:
In the above image from left to right: monocular, biocular, and binocular.
Night vision binoculars provide enhanced depth perception and are often used for surveillance or observation.
5. Helmet-mounted night vision systems:
Night vision units designed to be worn on helmets, often used by military personnel.
6. CCTV night vision cameras:
Surveillance cameras with built-in infrared LEDs to monitor areas in complete darkness.
Is night vision green?
Yes, the above picture shows what night vision looks like. Night vision goggles are green for a simple, yet powerful reason—human eye sensitivity.
The human eye is most sensitive to green light, particularly around 555 nanometers. This means we can distinguish more shades of green than any other color, giving us better detail in low-light situations.
But it’s not just about vision—comfort is key. Blake Gaughan, infantry platoon leader at Joint Base Lewis-McChord in Washington state says green light is less straining on the eyes, making it ideal for extended use, especially in tactical or military environments.
In fact, green phosphor screens became the go-to in early night vision tech because they struck the perfect balance between visibility and comfort. While newer technologies, like white phosphor, offer sharper contrast and more clarity, green remains the standard.
How does night vision work in physics?
Human eyes cannot see in darkness because they rely on visible light. When light levels drop below a certain threshold, vision becomes severely limited. This is where night vision systems step in to amplify faint light or detect heat signatures.
Night vision devices work by either capturing infrared light (which is invisible to the naked eye) or by making any available light, like from the moon or stars, brighter. This helps you see clearly in dark or dim environments where there’s not enough light.
Night vision process.
The military’s new gadget makes dark scenes visible by amplifying tiny amounts of light from the moon, stars, or other sources. It detects faint photons bouncing off objects, turns them into electrons, and amplifies them using a special glass plate. These electrons then hit a phosphor-coated screen to form an image.
Older devices use green phosphor, making night vision appear green. But Elbit’s latest tech uses white phosphor, creating black-and-white images with better contrast and clarity.
Night vision operates on the principles of light amplification and thermal detection. It’s important to understand two fundamental concepts in physics that enable night vision to function effectively:
Night vision vs. thermal imaging.
It’s common to confuse night vision and thermal imaging, but they are distinct technologies. Here’s a quick comparison to clarify their roles:
- Night vision technology focuses on amplifying available light or using infrared illumination to “see” in the dark.
- Thermal imaging detects heat signatures emitted by objects, making it highly effective for identifying living beings or warm objects, even through obstacles like fog or smoke.
If you need to see details in low light and there is some ambient light available, night vision is useful.
If you need to detect objects in complete darkness, through smoke, fog, or bright light conditions, thermal imaging is the superior choice.
| Feature | Night Vision Devices (NVG) | Thermal Imaging Cameras (FLIR) |
|---|---|---|
| Technology | Amplifies small amounts of visible light to create an image | Detects infrared (heat) radiation emitted by objects |
| How It Works | Magnifies available light and projects it onto a display | Detects temperature differences as small as 0.01°C and translates them into images |
| Light Requirement | Requires some ambient light (moon, stars, artificial sources) | Works in complete darkness, does not require any light |
| Image Type | Greenish or black-and-white images based on visible light | Black-and-white or color images based on heat differences |
| Performance in Twilight | Struggles due to too much or too little light | Works flawlessly in twilight or bright light |
| Glare Sensitivity | Affected by bright lights, which can cause glare and blindness | Unaffected by bright lights, can look directly at a spotlight without losing image quality |
| Effectiveness in Adverse Conditions | Cannot see through smoke, fog, or obstructions | Can see through smoke, fog, and some light obstructions |
| Daytime Use | Less effective in daylight due to excessive brightness | Works both day and night without performance loss |
| Heat Detection | Cannot detect heat signatures | Detects heat differences from objects, animals, and people, even in water |
Night vision in CCTV cameras:
Different types of CCTV cameras—like bullet, dome, and PTZ—come with night vision capabilities. But here’s the problem: most people don’t think about security cameras until they actually need the footage. And by then? It’s too late.
If your camera can’t see at night, what’s the point? Whether it’s a break-in, a suspicious visitor, or just checking on your property, visibility is everything. Investing in a high-quality night vision camera means you’re always covered—day or night.
How does night vision in CCTV cameras work?
Night vision security cameras work by using infrared (IR) light or low-light amplification to capture clear images in the dark. Most cameras have built-in IR LEDs, which emit light invisible to the human eye but detectable by the camera’s sensor, producing black-and-white night footage.
Higher-end cameras use low-light sensors (like Starlight or Lightfinder technology) to amplify existing light, allowing for full-color night vision even in near-total darkness.
Why does it matter?
Because 70% of crimes happen in low-light conditions. If your camera can’t see, you’re blind. If you’re blind, you can’t prevent anything. And if you can’t prevent anything, why even have a security system?
When do you actually need it?
If your business operates after hours, has low-light areas, or stores valuable assets, night vision security cameras aren’t optional—they’re essential. Crimes like theft, vandalism, and trespassing don’t follow business hours, and standard cameras are useless in the dark.
Whether it’s monitoring parking lots, warehouses, or entry points, a high-quality night vision system ensures clear footage, better security, and peace of mind—day or night.
Best night vision CCTV cameras.
Axis offers a wide range of cameras equipped with advanced night vision capabilities. Their products are designed to deliver high-quality video in various lighting conditions, ensuring reliable security monitoring around the clock.
In the above picture, we can see a night vision view with both lightfinder technology and IR mode.
- Lightfinder technology. You get high-resolution, full-color video with minimal motion blur, even in near darkness. By reducing noise, Lightfinder makes dark areas visible and captures fine details in very low light conditions.
- Infrared (IR) illumination. Many Axis cameras are equipped with built-in IR LEDs that provide illumination in complete darkness, ensuring clear black-and-white images when there’s no ambient light.
Now imagine these night vision cameras, combined with advanced video analytics and remote monitoring.
You get real-time alerts, instant decision-making, and automated responses with the combination of human expertise and AI. Whether it’s spotting an intruder in the dark or tracking unusual behavior, the camera AI triggers an alarm, and the remote operators spring into action.
FAQs about night vision technology.
Does night vision work in total darkness?
Yes, IR-based night vision systems can work in total darkness by emitting and capturing invisible infrared light.
How does night vision really work?
Night vision amplifies low levels of available light or uses infrared illumination to create visible images from the absence of natural light.
Does night vision work without any light?
If there’s no ambient light, infrared-based systems or thermal imaging will still provide visibility.
Is night vision illegal?
Night vision is not illegal in general but certain high-powered devices (like military-grade goggles) may be restricted due to their advanced capabilities.
Conclusion:
Night vision works through infrared illumination, light amplification, or thermal imaging.
Night vision technology has transformed security, surveillance, and tactical operations by enabling clear visibility in low-light or complete darkness.
These systems help businesses, homeowners, and professionals stay protected when visibility matters most.
Investing in the right night vision camera means you’re never left in the dark—literally and figuratively. Whether monitoring a warehouse, securing a remote site, or protecting your home, clarity at night is the difference between safety and vulnerability.
Contact us today for a free consultation on how you can protect your business 24/7.
