Does the night vision device work underwater?
Most night vision devices are designed to be used in low light conditions, but not all of them are able to function underwater. Can the EOPs withstand pressure and moisture? Which models have a sealed housing and do they remain effective in the water environment? In this article, we will look at how different types of EODs behave underwater, what limitations exist, and what to consider when choosing a device for underwater use.
Understanding night vision technologies underwater
Night vision underwater has become possible thanks to the development of electron-optical technologies. While traditional night vision devices such as scopes, binoculars, and goggles work effectively in the air, their use underwater is limited due to other optical properties of the environment and the absorption of infrared radiation.
Under standard conditions, night vision relies on an electron-optical converter (EOC) that amplifies available light or infrared radiation. The EOC converts photons into electrons, amplifies them, and converts them back into an image visible to the eye. As a result, objects that are invisible in the dark are made visible through contrast and brightness, often with color enhancement.
However, in water, infrared radiation is rapidly absorbed, especially at wavelengths used in most night vision devices. Therefore, conventional CCDs do not provide effective vision at a distance underwater. Specialized technologies are used for underwater night vision, such as active IR illumination with shorter wavelengths or alternative methods such as sonar.
Does the night vision device work underwater?
Most night vision devices are designed to be used in low light conditions, but not all of them are able to function underwater. Can the EOPs withstand pressure and moisture? Which models have a sealed housing and do they remain effective in the water environment? In this article, we will look at how different types of EODs behave underwater, what limitations exist, and what to consider when choosing a device for underwater use.
Understanding night vision technologies underwater
Night vision underwater has become possible thanks to the development of electron-optical technologies. While traditional night vision devices such as scopes, binoculars, and goggles work effectively in the air, their use underwater is limited due to other optical properties of the environment and the absorption of infrared radiation.
Under standard conditions, night vision relies on an electron-optical converter (EOC) that amplifies available light or infrared radiation. The EOC converts photons into electrons, amplifies them, and converts them back into an image visible to the eye. As a result, objects that are invisible in the dark are made visible through contrast and brightness, often with color enhancement.
However, in water, infrared radiation is rapidly absorbed, especially at wavelengths used in most night vision devices. Therefore, conventional CCDs do not provide effective vision at a distance underwater. Specialized technologies are used for underwater night vision, such as active IR illumination with shorter wavelengths or alternative methods such as sonar.
Before purchasing an expensive night vision device, you should clearly understand its purpose and how it works. It is not enough to know about the presence of a lens, radiation receiver, display, and amplifier - it is important to take into account the operating environment and physical limitations of the technology.
The reflected light from the monitored object enters the input lens, which collects and focuses it on the photocathode. Then, an electronic optical converter (EOC) amplifies this light and transmits the image to the screen. This is a passive mode of operation in which the device amplifies the available light radiation.
In complete darkness, when there is no light source, there is nothing to amplify - the device becomes ineffective. In this case, infrared illumination is used, which can be built-in or external. It allows you to work in absolute darkness by switching the device to active mode.
Modern night vision devices can be based on both CCDs and digital matrices. Even advanced and experimental devices retain the principle of operation - amplification of weak light - but use new technologies to improve image quality. Although different generations of devices have different characteristics and costs, they all work on the same basic principle: light amplification.
Thermal imagers and digital devices do not use an electronic optical converter (EOC), which distinguishes them from classic night vision devices.
Thermal imag ers detect infrared radiation emitted by objects with different temperatures. They are effective in conditions of complete darkness, smoke, fog, and can also detect targets hidden in vegetation, such as animals in bushes, grass, or reeds. However, their effectiveness decreases at high ambient temperatures - typically above +35 °C - due to a decrease in the temperature contrast between the targets and the background.
Digital devices work on the basis of a light-sensitive matrix (e.g., CMOS or CCD) that converts the collected light into a digital signal. Such devices can operate in both day and night mode, often with near-infrared illumination.
| Technology | Principle | Behavior in the water | Illumination | Pros | Limitations | Typical tasks |
|---|---|---|---|---|---|---|
| EOP (classical firewall) | Amplify existing light | Efficiency drops quickly due to IR absorption and scattering in turbid water | Mostly needed; standard 850-940 nm are weak in water | Low latency, natural "picture" | Sealing requirements; very limited distance | Short-range navigation in clear water |
| Digital NV (CMOS/CCD) | Light-sensitive matrix + processing | Similar limitations, but more flexible backlight/filter control | Often closer IR/visible light with filters | Record/stream, digital enhancements | Noise/latency; dependence on light source | Training, training dives, close-up inspection |
| Thermal imager (LWIR/MWIR) | Registration of thermal radiation | It practically does not "see" in water: IR is strongly blocked | Not necessary, but almost useless underwater | Very effective above water for surface inspection | Does not work at a distance underwater; only sees the surface/local environment | Search for targets above water, control surface temperature |
Before purchasing an expensive night vision device, you should clearly understand its purpose and how it works. It is not enough to know about the presence of a lens, radiation receiver, display, and amplifier - it is important to take into account the operating environment and physical limitations of the technology.
The reflected light from the monitored object enters the input lens, which collects and focuses it on the photocathode. Then, an electronic optical converter (EOC) amplifies this light and transmits the image to the screen. This is a passive mode of operation in which the device amplifies the available light radiation.
In complete darkness, when there is no light source, there is nothing to amplify - the device becomes ineffective. In this case, infrared illumination is used, which can be built-in or external. It allows you to work in absolute darkness by switching the device to active mode.
Modern night vision devices can be based on both CCDs and digital matrices. Even advanced and experimental devices retain the principle of operation - amplification of weak light - but use new technologies to improve image quality. Although different generations of devices have different characteristics and costs, they all work on the same basic principle: light amplification.
Thermal imagers and digital devices do not use an electronic optical converter (EOC), which distinguishes them from classic night vision devices.
Thermal imag ers detect infrared radiation emitted by objects with different temperatures. They are effective in conditions of complete darkness, smoke, fog, and can also detect targets hidden in vegetation, such as animals in bushes, grass, or reeds. However, their effectiveness decreases at high ambient temperatures - typically above +35 °C - due to a decrease in the temperature contrast between the targets and the background.
Digital devices work on the basis of a light-sensitive matrix (e.g., CMOS or CCD) that converts the collected light into a digital signal. Such devices can operate in both day and night mode, often with near-infrared illumination.
| Technology | Principle | Behavior in the water | Illumination | Pros | Limitations | Typical tasks |
|---|---|---|---|---|---|---|
| EOP (classical firewall) | Amplify existing light | Efficiency drops quickly due to IR absorption and scattering in turbid water | Mostly needed; standard 850-940 nm are weak in water | Low latency, natural "picture" | Sealing requirements; very limited distance | Short-range navigation in clear water |
| Digital NV (CMOS/CCD) | Light-sensitive matrix + processing | Similar limitations, but more flexible backlight/filter control | Often closer IR/visible light with filters | Record/stream, digital enhancements | Noise/latency; dependence on light source | Training, training dives, close-up inspection |
| Thermal imager (LWIR/MWIR) | Registration of thermal radiation | It practically does not "see" in water: IR is strongly blocked | Not necessary, but almost useless underwater | Very effective above water for surface inspection | Does not work at a distance underwater; only sees the surface/local environment | Search for targets above water, control surface temperature |
Does the night vision device work underwater?
Conclusion in brief
- Yes, UXOs can operate underwater, but only in specially sealed models with the declared protection class (e.g. IP68) and pressure rating.
- IR waves in water quickly fade away - standard 850-940 nm lights hardly cover the distance; alternatives (closer ranges/visible light) or other methods are needed.
- Thermal imagers underwater are practically ineffective: water blocks infrared radiation, so the camera can only see the immediate environment.
- Critical: Turbidity, suspended solids, salinity, and temperature significantly reduce contrast.
Yes, night vision devices can work underwater, but only if they are specially designed. There are models designed to be used in full immersion conditions, such as military operations, search and rescue, diving, and underwater hunting.
Such devices have a sealed housing and meet waterproofing standards (e.g. IP68 or MIL-STD-810), which allows them to operate at depth without damaging the electronics or optics.
What IP and MIL-STD-810 mean for underwater use
- IP rating (IEC 60529): the second digit indicates protection against water. IP68 = dustproof and continuous immersion to the conditions specified by the manufacturer (depth/time).
- MIL-STD-810: a set of test methods for durability (shock, vibration, temperature, immersion, etc.). This is not a direct "water rating" but a confirmation of endurance according to the standard's procedures.
- Practical: check the passport parameters of a particular model (maximum depth, duration, type of water - fresh/salty).
The key factor is the medium of light propagation. Infrared radiation propagates differently in air than in water. Water significantly absorbs IR radiation, especially long-wave radiation (850-940 nm), which limits the effectiveness of conventional IR lights. Therefore, for underwater applications, special sources of a shorter IR range or active optics with their own illumination in the visible spectrum are used.
It is also necessary to take into account the influence of suspended particles in the water - silt, sand, plankton - which scatter light and reduce image contrast. This requires high sensitivity of the electron-optical converter (EOC) and high-quality optics with anti-reflective coatings.
Night vision technologies for underwater use
Underwater night vision is critical for orientation and safety during dives in the dark. The effectiveness of such devices is based on the ability to capture and amplify reflected light, even in minimal light.
Modern night vision devices for underwater use are equipped with electronic optical transducers (EOTs) that provide clear images in low light conditions. They have a sealed housing that is resistant to pressure and water penetration, which allows them to be used underwater without losing functionality.
Such devices are actively used by divers, military units and underwater hunters. Underwater night vision goggles are specially designed to operate in complete darkness, providing stable visibility and facilitating orientation in the water environment.
Does the night vision device work underwater?
Conclusion in brief
- Yes, UXOs can operate underwater, but only in specially sealed models with the declared protection class (e.g. IP68) and pressure rating.
- IR waves in water quickly fade away - standard 850-940 nm lights hardly cover the distance; alternatives (closer ranges/visible light) or other methods are needed.
- Thermal imagers underwater are practically ineffective: water blocks infrared radiation, so the camera can only see the immediate environment.
- Critical: Turbidity, suspended solids, salinity, and temperature significantly reduce contrast.
Yes, night vision devices can work underwater, but only if they are specially designed. There are models designed to be used in full immersion conditions, such as military operations, search and rescue, diving, and underwater hunting.
Such devices have a sealed housing and meet waterproofing standards (e.g. IP68 or MIL-STD-810), which allows them to operate at depth without damaging the electronics or optics.
What IP and MIL-STD-810 mean for underwater use
- IP rating (IEC 60529): the second digit indicates protection against water. IP68 = dustproof and continuous immersion to the conditions specified by the manufacturer (depth/time).
- MIL-STD-810: a set of test methods for durability (shock, vibration, temperature, immersion, etc.). This is not a direct "water rating" but a confirmation of endurance according to the standard's procedures.
- Practical: check the passport parameters of a particular model (maximum depth, duration, type of water - fresh/salty).
The key factor is the medium of light propagation. Infrared radiation propagates differently in air than in water. Water significantly absorbs IR radiation, especially long-wave radiation (850-940 nm), which limits the effectiveness of conventional IR lights. Therefore, for underwater applications, special sources of a shorter IR range or active optics with their own illumination in the visible spectrum are used.
It is also necessary to take into account the influence of suspended particles in the water - silt, sand, plankton - which scatter light and reduce image contrast. This requires high sensitivity of the electron-optical converter (EOC) and high-quality optics with anti-reflective coatings.
Night vision technologies for underwater use
Underwater night vision is critical for orientation and safety during dives in the dark. The effectiveness of such devices is based on the ability to capture and amplify reflected light, even in minimal light.
Modern night vision devices for underwater use are equipped with electronic optical transducers (EOTs) that provide clear images in low light conditions. They have a sealed housing that is resistant to pressure and water penetration, which allows them to be used underwater without losing functionality.
Such devices are actively used by divers, military units and underwater hunters. Underwater night vision goggles are specially designed to operate in complete darkness, providing stable visibility and facilitating orientation in the water environment.
When choosing diving equipment, you should consider the depth of immersion for which a particular device is designed. Reliable water resistance is a critical feature for safe operation underwater.
Checklist before purchasing an underwater air defense system
- Check the protection class (IP) and the certified depth/immersion time of this particular model.
- Evaluate the visibility of the water (turbidity, suspended solids, salinity) - this is the main factor in contrast.
- Specify the range of illumination: near-infrared or visible illumination with filters; availability of power control.
- Look at the optics: anti-reflective coatings, the quality of sealing of the components.
- Pay attention to power supply and autonomy in cold/salt water.
- For studying, digital (recording/streaming) is preferred, and for short tasks, a properly backlit CRT is preferred.
- Are you planning to use salt water? Check the corrosion resistance and care/rinsing instructions.
- Pre-mission test: calibration, sealed lids, seals check, backup lighting.
Important: thermal imagers (LWIR/MWIR) in water almost do not work at a distance - water absorbs thermal radiation. Such cameras are useful above water (surface monitoring), but underwater they provide information only about the very close environment.
Frequently asked questions
Can I use a conventional ECD underwater?
Only if the model has a sealed housing with a confirmed protection class and immersion parameters from the manufacturer.
Why does infrared lighting work worse in water?
Water intensively absorbs near-infrared light (in particular, the 850-940 nm range), and suspended particles additionally scatter light, which dramatically reduces distance and contrast.
Does the thermal imager work underwater?
Practically not: water blocks thermal (infrared) radiation; the thermal imager is effective above water, but underwater it is almost "blind".
What is IP68 and how does it differ from MIL-STD-810?
IP68 describes dust protection and immersion under the manufacturer's conditions. MIL-STD-810 is a set of endurance tests (shock, temperature, immersion, etc.). These are different systems.
What kind of illumination is best for underwater EO?
The shorter the wavelength (up to the limits of the visible spectrum) and the better the collimation/filtration, the higher the efficiency; but consider masking and safety regulations.
When choosing diving equipment, you should consider the depth of immersion for which a particular device is designed. Reliable water resistance is a critical feature for safe operation underwater.
Checklist before purchasing an underwater air defense system
- Check the protection class (IP) and the certified depth/immersion time of this particular model.
- Evaluate the visibility of the water (turbidity, suspended solids, salinity) - this is the main factor in contrast.
- Specify the range of illumination: near-infrared or visible illumination with filters; availability of power control.
- Look at the optics: anti-reflective coatings, the quality of sealing of the components.
- Pay attention to power supply and autonomy in cold/salt water.
- For studying, digital (recording/streaming) is preferred, and for short tasks, a properly backlit CRT is preferred.
- Are you planning to use salt water? Check the corrosion resistance and care/rinsing instructions.
- Pre-mission test: calibration, sealed lids, seals check, backup lighting.
Important: thermal imagers (LWIR/MWIR) in water almost do not work at a distance - water absorbs thermal radiation. Such cameras are useful above water (surface monitoring), but underwater they provide information only about the very close environment.
Frequently asked questions
Can I use a conventional ECD underwater?
Only if the model has a sealed housing with a confirmed protection class and immersion parameters from the manufacturer.
Why does infrared lighting work worse in water?
Water intensively absorbs near-infrared light (in particular, the 850-940 nm range), and suspended particles additionally scatter light, which dramatically reduces distance and contrast.
Does the thermal imager work underwater?
Practically not: water blocks thermal (infrared) radiation; the thermal imager is effective above water, but underwater it is almost "blind".
What is IP68 and how does it differ from MIL-STD-810?
IP68 describes dust protection and immersion under the manufacturer's conditions. MIL-STD-810 is a set of endurance tests (shock, temperature, immersion, etc.). These are different systems.
What kind of illumination is best for underwater EO?
The shorter the wavelength (up to the limits of the visible spectrum) and the better the collimation/filtration, the higher the efficiency; but consider masking and safety regulations.
Does the night vision device work underwater?