Most folks who’re new to night hunting, deep water fishing, or diving in general, often get confused about night vision. But, night vision is the center of talk for sure! A staggering 1.5 billion dollar market for night vision gadgets in North America alone suggests that as well.
The common question I get is this: does night vision work underwater? Can I really see underwater when it’s dark down there? If so, what do I need to get my eyesight back underwater without using flashlights? Well, that’s what we’re talking about today.
Let’s discuss how night vision works, how it enables you to see in the dark, and if it also works underwater.
How Does Night Vision Work?
Before we get into the specifics, let’s discuss what is night vision in the first place and how it works.
Simply put, night vision is a technology that enhances the images in front of the lenses and illuminates the sight. It sends infrared lights, collects that back to a receptor, and amplifies the image in front of you. In simple words, it enables your vision to see in the dark where human vision fails.
The process of night vision goes into steps: It collects small lights from an object through a photocathode, to a microchannel plate before showing the result onscreen/eyepiece. You’ll see the final result in green color because of the reaction between the present phosphate and the collected photons.
There are many NVDs (Night Vision Devices) available in the market including googles, thermal night vision cameras, and night vision scopes.
However, the night vision cameras work with thermal imaging technology instead of the image enhancement mentioned earlier. They sense heat signatures from sources anywhere between -20° C to 2000° C, which is called a thermogram. After that, the collected data translate into an image that produces images with multiple colors representing different heat levels.
Another type of night vision device is a combo of both thermal imaging and IR vision. They collect ambient light from other light sources like stars and moon, does thermal imaging, and use IR illumination for much brighter, color vision images.
Does Night Vision Work Underwater?
Night vision on the land is common across industries from military warfare, hunting, to search and rescue and surveillance systems. But, what about underwater? Does night vision work underwater? Can you dive in the ocean and still see in the pitch dark? If you can, what type of equipment are you going to need? Let’s find out.
1. Night Vision Googles
First, let’s talk about the most common gear that people use to see in the dark underwater, and that’s night vision googles. There are different types of underwater googles, among which some include more than just glasses and straps.
You’ll get special devices attached to the googles to help you clear your vision in the dark, and more. By more, I mean water makes uneven reflections all around, with waves, all the time. And when you use regular infrared systems, they fail to get the infrared back to the receptor because of the uneven water reflectors.
Therefore, you need a special technology called Pulse Laser Range Gating that can ignore the odds underwater and remove darkness. It shoots laser instead of infrared rays with a flushing sequence within a short time window at a certain distance. And these underwater night vision goggles are smart enough to ignore issues like turbulence and constant changes in the water waves that alter infrared.
Here is how it works:
Apart from that, there are also practices of doing underwater night vision jobs with IR and UTOFIA camera systems. The traditional IR systems don’t do any good when it comes to deep underwater inspections, since they need some sort of external source to reflect on without any interruptions. With UTOFIA cameras, however, the results could be slightly improved than with the IR modules.
But none of the other systems can perform near perfect as the Laser Range Gating technology. So, there you have it, the anatomy of seeing underwater with smart googles that illuminate your vision in the dark sea.
2. Night Vision Cameras
Night vision cameras, on the other hand, aren’t common in underwater inspections or active underwater jobs. They’re usually used for search and rescue, construction, and other professional purposes. They can’t catch a heat source (since they use thermal imaging) underwater.
Here’s a little demo for your understanding:
On the flip side, there are special cameras that do only underwater jobs like finding fish and doing underwater inspections. There are Sonar Sensor Transducer systems that help people for fishing without using a real camera. They give you a visible idea of how far the fish approximately is to drop the lure.
Some others also include cameras to find the fish around under the dark water. These cameras don’t really do very well and have dull image qualities with green tints all over, like this one:
Another type of camera worth mentioning is the fishing-specific night vision camera with IR LEDs on the head. Just like the ones you see with the surveillance cameras. They illuminate the area in front of the camera within a small range and give you an idea of what’s under the lure. The camera connects to the fishing rod using a cable apart from the fishing line itself, like this one:
Do Night Vision Goggles Glow in the Dark When Turned on?
Yes, night vision googles do illuminate when you turn them on as they enhance the collected image of the target. Hence, if you’re working with an objective of lying low, chances are, you’ll end up exposing your position, especially if your opponent is also wearing a night vision camera.
However, you can avoid exposing yourself because of the glow if you use a rubber eye cup on the contact. It will not only keep the glow isolated, but also give your eyes the relief you need while wearing the night vision sight for long. However, that’ll limit your peripheral vision, although it will cut the blue light spectrums in darkness.
Underwater activities are fun, and making the best use of your underwater time requires the right gear. A night vision sight that clears the dark field of vision is unparalleled to any other sighting gear you can own.
Now that you know how does night vision work underwater, selecting the right device will be a lot easier if you need one. You’ll need glasses that can see through the water with Pulse Laser Range Gating technology in it (not the auto gate one, if you’re wondering).