How Does Night Vision Work? | Night Vision Goggles & Scopes

Most of us know what night vision is. It gives us the ability to see in the dark and in very low-light conditions. But have you ever wondered how night vision works and why some animals have the ability to see and navigate their way in the dark easily? Join us as we answer these questions and discuss some more interesting points, such as use cases and night vision rifle scopes explained.

How Does Night Vision Work? (Technology Explained)

image of man with night vision goggles

1) Optoelectronic Image Enhancement

Optoelectronic image enhancement (OIE), also known as image intensification, is a method that amplifies ambient light, creating a visible image. Many of the Best NV Scopes under $1000 use this technology. There are five main components that these types of night vision devices consist of:

Objective lens: Avid readers know how much I emphasize the size of the objective lens. The objective lens is very important because it collects ambient light. Theoretically, the bigger the objective lens in diameter, the more light is transmitted.

Photocathode: The light transmitted from the objective lens is focused on the photocathode. The light, which is in photon form, is converted into electrons.

Microchannel plate (MCP): From there, the electrons are emitted to the MCP – a thin, glass plate containing millions of microscopic channels. As the electrons pass through the thin filaments of the MCP, they collide against the channel walls. These collisions create a cascade of more electrons. This process is crucial because it amplifies the original signal.

Phosphor screen: The phosphor screen converts the electrons back into photons – creating a visible image. The green light you see through a night vision device is because of this phosphor screen.

The green light has been found to be the most effective color for night vision goggles as the human eye is the most sensitive to green light – making it easier for users to perceive details from the night vision equipment.

Eyepiece: The eyepiece is the piece you put against your eye. It focuses on the image created by the phosphor screen.

2) Digital Image Enhancement

Digital image enhancement relies on digital imaging technology to improve the visibility of a visual picture in low-light conditions. Many of the Best Coyote Hunting NV Scopes use this technology. This night vision technology also relies on several main components to ensure it produces quality images.

Image sensor: The image sensor is either made from CMOS or CCD sensors. These sensors capture the visible light from the scene, much like the objective lens of the first-mentioned night vision technology.

The sensors consist of a grid of light-sensitive pixels that convert the photons into electrons. The more visible light is present, the better the night vision image will be.


Digital Signal Processor: The digital signal processor (DSP) is basically an image intensifier tube to produce clear night vision images. First, the electrons from the pixels in the image sensor are converted into a digital signal.

Then, a DSP applies image processing techniques to improve the quality of the digital night vision image. These techniques include noise reduction, contrast enhancement, edge enhancement, and image stabilization.

Display: Finally, the processed digital image is displayed on a screen, allowing users to view the night vision generations.

The digital image enhancement night vision goggles work much better than the OIE technology. It works better in low light conditions, can incorporate an additional zoom and video recording function, and is less susceptible to bright light sources.

What Are Night Vision Goggles?

Night vision goggles are imaging devices designed to enhance your visual ability in low-light conditions. These goggles incorporate the technology mentioned in the prior sections to amplify the ambient light, such as moonlight, into a scene and create a visual image.

Unlike thermal imaging cameras that use infrared light, night vision goggles rely on a light source to produce images. Therefore, thermal scopes are better for when no light is present, and night vision goggles are used when some source of light is present – even if it is just moonlight.

Night vision goggles are either handheld or helmet-mounted. Other examples of night vision devices include night vision binoculars, rifle scopes, or monoculars.

Night Vision Rifle Scopes Explained

Night vision rifle scopes allow users to aim and shoot accurately in low-light or nighttime conditions. I especially use night vision rifle scopes for varminting, such as hogs. There are even hog hunting night vision scopes that specialize in nighttime hunting!

Night vision rifle scopes use traditional night vision technology I mentioned earlier in conjunction with a traditional rifle scope’s features, such as magnification, reticles, and windage and elevation adjustments.

A night vision rifle scope can either use optoelectronic or digital image enhancement technology, and the type used depends on the manufacturer’s preference.

Some night vision scopes even have thermal imaging capabilities – allowing these scopes to still produce a visual on targets even in complete darkness.

Why Can Animals See In The Dark But Not Humans?

Time for some biology 101. Some animals, such as cats, dogs, and nocturnal species, see much better than humans in the night. This is because they have specific adaptations in their eyes that allow them to see more effectively in low-light conditions. These biological adaptations include:

  • Rod cells: Rod cells are one of the two photoreceptor cells in the retina, the other being cones. Rod cells are more sensitive to light and are responsible for vision in low-light conditions. Animals with better night vision have a higher concentration of rod cells than humans in their retinas.
  • Tapetum lucidum: The tapetum lucidum is a reflective layer behind the retina present in most nocturnal animals. This layer reflects light back into the eye as it passes through the retina – increasing the amount of light the photoreceptor cells detect and hence better visibility in low light conditions. Humans don’t have a tapetum lucidum.
  • Pupil size and shape: Think of the pupil as the objective lens of an animal. It is the opening of the eye that allows light to enter. Nocturnal animals typically have larger pupils that can also dilate more than human pupils. Additionally, slit-shaped pupils, present in cats, can open wider round pupils – allowing better light transmission.
  • Eye positioning: Some animals, like owls, have forward-facing eyes that provide them with better depth perception and a wider field of view in low ambient light conditions.

Best Use Cases For Night Vision

1) Hunting

As I’ve already mentioned, I hunt a lot with night vision scopes. They are ideal for hunting undetected at night – a crucial factor for varmint hunting.

2) Spotting

Night vision is also very useful for spotting activities such as bird watching at night or safaris. Most predators are only active at night; by using a night vision scope, you can be part of this nightlife activity and experience every moment firsthand.

3) Military Use

Military personnel regularly employ night vision scopes on their missions and ops that require stealth. They are very effective at detecting enemies at night – giving military personnel the edge in life-and-death situations.

Frequently Asked Questions

Can night vision work in total darkness?

Unfortunately not, night vision is restricted to use in conditions where a faint source of light is still present. Thermal imaging, however, functions optimally in total darkness.

Is night vision illegal?

Night vision is legal in the United States. Civilians can legally purchase and use night vision devices without any restrictions.

Are humans capable of night vision?

Humans do have the ability to see at night, but we still rely on a source of light to create a visual image in our brains. Therefore, our night vision capabilities are very basic and much less than most predator and nocturnal animals.

What is the lifespan of the night vision rifle scope?

The lifespan of a night vision rifle scope depends on various things, from light exposure to maintenance and care. However, image intensification scopes usually last around 4,000 hours - one of mine lasted around 3,000 hours. While digital image enhancement tends to last longer.

The Bottom Line

Night vision scopes have opened the door for various nighttime activities. The technology behind it is pretty basic when stripped down to its main components. And although humans are capable of slightly seeing in the dark, it’s nothing compared to our animal counterparts. If you recently bought a night vision scope and would like to know how to sight it in your NV scope, you can follow our detailed guide.

About the author

Patrick Howard

I have been working as a gunsmith for 20 years. Rain, fog, moisture, high temperature, or even snow are all the things a product must withstand in order to be recommended by me.

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