The right tool for the right task is essential, just like a good hand drill for a DIY project. Just the same, to see in the dark, you need the right type of equipment and night vision goggles are advertised to do the trick. If you have ever watched an action movie, you might have noticed the use of such equipment.
However, the natural question that comes to mind, seeing how special effects and make-believe are the bread and butter of cinematic productions, is whether the kind of night vision equipment you buy from stores works just like that or not.
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For night vision goggles to work, there must be light
One of the most common misconceptions related to such equipment is that it can help you see in pitch black conditions. That’s not the case. The optics inside it needs at least a source of light, no matter how faint – such as the light of the moon – in order to work.
In a nutshell, you should know that night vision goggles will help you see in the dark, provided that the condition mentioned earlier is met. To give you an idea about what such goggles can do, let us tell you that your eyes will be able to see things that are up to 200 yards away from you. Pretty impressive, right?
What technologies are involved?
As expected from such specialized optics, night vision is the result of specific technologies that make it happen. One such technology is called image enhancement, and its role is to collect tiny light particles from the entire spectrum, which includes infrared. While you can’t see these specks of light with the naked eye, when they are enhanced by this technology, they are enough to make you see in the dark.
The other technology that is used by night vision is named thermal imaging. While image enhancement works with light from the full spectrum, thermal imaging works only with the upper area of the infrared light. That sort of light is actually heat, hence the name of the technology.
In other words, what you might have seen in sci-fi and action movies where a human threat is identified due to the body heat emitted is not off the mark.
How are the two technologies used?
Night vision can use both of the above, but some differences appear due to certain specifics. You should know that the vast majority of night vision goggles you can find right now are based on thermal imaging, while image enhancement based on the infrared vision comes in handy for security cameras.
A brief explanation of the infrared vision
Since we focus more on night vision goggles in this article, we will not insist too much on infrared vision. A summary is in order, nonetheless. If you have ever looked at a security camera, you probably noticed that it comes with a lot of small LEDs. These are used to create enough light for the camera to capture images.
While it’s called infrared vision, through security cameras, it delivers images in black and white. That is necessary for the clarity of the vision, as other colors can make the image muddy and hard to decipher by the human eye.
What is thermal imaging, and how does it work?
While security cameras use infrared vision emitted by their LEDs, thermal imaging depends only on the light emitted by the objects caught through the objective lenses. Pitch black conditions are challenging to obtain out in the open, where there’s always the light of the celestial bodies, even when clouds cover the sky.
Using the light from the environment, the optics in night vision goggles is capable of creating something named a thermogram. This is a temperature pattern determined by the infrared detector compounds in the equipment you use.
The light emitted as heat is registered and interpreted as electronic impulses. These are then collected by a circuit board where the information is processed for delivery into what you know as the display data. Together they will form more than a map; they will create an image that, indeed, helps you understand what lies in front of your eyes in the dark.
Learning about various night vision equipment
With the help of the technology mentioned above, manufacturers create multiple night vision items. For instance, you can get a scope with night vision. Scopes are pretty helpful since they are easy to hold or to mount on a rifle, for example. Hunters who prefer to go hunting at night know the importance of identifying various wild animals in the dark.
The most popular, without a doubt, must be night vision goggles. Because they are pretty much like binoculars, they are effortless to use, and you don’t have to mount them on other equipment. While scopes are a better choice when you want to look at something through the lenses of the optics equipment and then return to normal viewing.
Night goggles, on the other hand, are for people who need to have proper night vision all the time. Last, but not least, there are cameras with night vision that can be used for security and surveillance.
Can you see anything if there’s no light?
Your night goggles won’t be on the same level with the make-believe items used in James Bond movies, so you might wonder what you can do when the lack of light can be an issue. That’s where thermal imaging comes into play and why it’s so important.
You surely have heard plenty about miners and other workers being saved from dark and cramped spaces like mine shafts and the like. As expected, those places can be in complete darkness, because they are deep underground.
Thermal imaging works by identifying the heat pattern map of what’s ahead. It is used for seeing firefighters through a curtain of black smoke, as well as for situations described earlier. Also, when objects don’t emit infrared light, if they are warm, they can still emit something called infrared radiation.
Good quality night vision goggles come equipped with CMOS and CCD sensors that can detect this low-frequency type of radiation. Even more, they use this information and translate it into photons so that you can see an image.
So, it depends a lot on what kind of purpose you want your goggles to have. If you go outside, image enhancement is the better technology. However, if you need to operate in complete darkness, thermal imaging is the better choice. Rescue teams use these goggles, and they are usually professional grade.
Why do you see only green images through your goggles?
That’s a pretty important question. You still remember the earlier information on how cameras with night vision show you images in black and white. There is a similar answer for the green image type delivered by your goggles.
The human eye is highly sensitive to green light, and that makes it possible for you to see details. Also, you will not experience fatigue when looking at something green for longer times. Imagine looking at the same image but in red or blue. Green is clearly the winning color.
Since that aspect was discovered, manufacturers decided to use the green colors for the image display for night vision goggles. So, if you’re wondering if your night vision goggles work like in the movies, the answer would be that they pretty much work like that, but maybe with less detail since movies tend to present things exaggeratedly.
Bear in mind that the military developed night vision goggles, so their focus was on making a product that would be comfortable to use for as long as it was needed. That explains the green color of the images you see with your night vision goggles, too.
Conclusion
You might not get the same quality of detail as you see in James Bond movies, but a pair of night vision goggles can help you see in the dark pretty well. There are two technologies used: image enhancement and thermal imaging, both with their clear advantages.
For activities such as hunting at night or surveillance, image enhancement is highly recommended. However, if you need to use night vision in pitch black conditions, such as underground, you will need thermal imaging. That’s the type of equipment rescue teams use when they need to look for survivors in mine shafts and the like.
