If you have ever tried a pair of night vision goggles, you most probably were impressed with their ability to help you see in the dark. Yet, you might have also wondered about their ability to do so when it’s pitch dark outside. The thing is that this type of goggles works in a particular manner; they take whatever light the environment supplies and intensify it.
That is the reason why they are often named image intensifiers, and that should give you a clear clue on how they truly work. Because the light used for this purpose is often infrared not visible with the naked eye, we often feel tempted to believe that it is genuinely dark outside. That is why night vision goggles might seem like such an excellent device.
So, the question starting this article still stands. Can a pair of such goggles work in absolute darkness? The direct and straightforward answer would be ‘no’, but a more elaborate response is needed, and this is the reason why.
Absolute darkness exists in only exceptional circumstances
Do you still recall how we talked about the infrared light just earlier? What we perceive as complete darkness with the naked eye is anything but, from a physics standpoint. What we don’t catch with our normal vision, our goggles do, and that is any tiny amount of light that comes from the environment.
Something as faint as the light given by the moon and the flickering stars up above can be harnessed and used by the goggles to present you with an accurate image of your surroundings. It may sound like as long as you are out in the open, there is a chance that the celestial bodies give enough light to ensure that your goggles will work.
What about other places? What about the bottom of a cave, or anywhere the natural light of the moon and the stars cannot reach? Again, there is an explanation why you can still use your goggles or a night vision monocular even when you are in such locations.
The thing is that everything that surrounds us and still has a temperature that is above absolute zero still emits some infrared light. That is enough for your night vision goggles to work, and that is why they are so useful for many categories of users. The chances are that you will not encounter absolute darkness conditions as a general rule.
Why are some goggles more powerful than others?
Taking into account all the information supplied earlier, you are probably wondering if just any goggles will work. The truth is that some models work better than others, due to how they are designed and especially the quality of the optics installed on them. For instance, models that have multi-coated lenses, and also have some anti-reflective properties, will do a better job at harnessing the light from your surroundings to provide you with an image that is not deterred by insufficient light.
Another feature that might significantly improve the abilities of a pair of goggle is a built-in illuminator. This will create more infrared light for the goggles to catch and process for the image you can then see through them. One thing you should bear in mind, however, is that no illuminator can provide the same viewing distance that you would be able to take advantage of in normal light conditions.
Nonetheless, the better equipped your goggles are, the better the quality of the image you will be able to observe through their lenses.
Are there other devices that can be used?
Night vision goggles are not the only devices you can take advantage of to see more clearly in the dark. They do have their benefits, as they are easy to use and very convenient regarding portability and the like. Some people opt for survival monoculars when they want to gauge their surroundings, but they could, just as well, prefer goggles due to the advantages mentioned earlier.
Nonetheless, there are situations when the use of other types of devices is required. For instance, firefighters need other aids to see through smoke. Thermal imaging is the technology they need to see through the blanket of smoke that can cover a location that is engulfed by flames. There are special optics-based devices that cater to such specific needs, so night vision goggles don’t have such extensive applications.
Where thermal imaging devices differ from regular goggles to be used at night is at their ability to capture the heat signature provided by any body with a temperature above absolute zero. Computer-enhanced screens also contribute to the efficiency of these devices that are often used to identify survivors in various emergency conditions.
The purpose of this article is to offer you a comprehensive answer to the question in the title. While night vision goggles cannot work in absolute darkness, the thing is that most of the time, you don’t need them to deliver such impossible performance. For what they are created to do, they do a fantastic job, as they can work with sources of light that are invisible to the naked eye.
You must bear in mind that these goggles work with the tiniest of light sources that are delivered by the environment. However, since almost everything around us is capable of emitting light, even if it is the infrared kind, your goggles can catch this light and turn it into the image you will be able to observe through your goggles.
When presented with various options of night vision goggles, it is preferable that you go for a model that comes with enhanced optics and a built-in illuminator, as this helps a great deal with rendering a clearer image through your goggles.
For more demanding applications, such as identifying survivors in case of emergencies, other optics-based products such as thermal imaging devices are more indicated.