There is absolutely no debate that increasingly compact night vision optics and cameras have fundamentally changed the nature of warfare, as well as law enforcement and a host of other activities. But as revolutionary as these systems have been, they have historically been limited to producing monochrome imagery that can make it difficult to determine many important details at even modest ranges. In recent years, however, there have been significant developments in technology that makes it possible to see in the dark and in full color, making it easier to quickly identify items of interest and drastically increasing a user’s overall situational awareness.
For decades now, there has been steady research and development into what is commonly described as “color night vision.” In the past 10 years, a number of different manufacturers have begun to sell more practical systems on the commercial market and the technology is already in use in military and security applications, among others.
Las Vegas-headquartered SPI Corporation’s X27 Osprey full motion video camera is a great example of how far the technology has come, providing impressive color imagery in very low-light-level conditions. It’s hard to believe that the videos below were shot at midnight in their respective locations.
The first true passive night vision systems, which appeared in the 1960s, used an image intensification “tube” to capture any available photons of ambient light and then “energize” those particles. These excited light particles then go through this process multiple times. The resulting “image” then ends up projected onto what is effectively a small screen at the other end of the system, appearing much brighter to the human eye and thereby making the entire scene visible in low-light conditions.
The 1974 U.S. Army video below offers a more in-depth overview of how image intensifying night vision works at its most basic level.
Decades of additional research mean that these systems are now able to amplify smaller amounts of light and create higher fidelity imagery. Today, the current generation of night vision optics are also able to faster and automatically account for changes in ambient light, preventing the user from getting blinded if things rapidly become brighter or losing the picture altogether, even briefly, if the available light drops.
But the picture in most of the night visions systems in active use today is generally only available in monochrome, usually with a stereotypical green tinge. This is because the systems are simply not sensitive enough to capture enough light to amplify into a color picture in extremely low-light-level conditions. Think of this sort of like walking into a mostly darkened room. You might be able to identify some objects, but your brain can’t produce a vibrant color image.
This traditional night vision imagery can make it difficult to isolate and identify particular details on a target to help positively identify it. In a military or law enforcement context, this is extremely important since it can make it hard to tell a threating individual from an innocent bystander or a truck with some odd cargo from a vehicle with a mounted weapon. It might even make it problematic to discriminate between friendly and hostile forces in the middle of a firefight.
Many higher-end color night vision systems, such as the X27, as well as Canadian firm Lorex’s security cameras, dispense with the image intensification tube in favor of a highly sensitive, digital complementary metal-oxide semiconductor (CMOS) imaging sensor. These translate photons into electrons that an algorithm then decodes to produce a digital image. CMOS technology is commonly found in commercial digital cameras, as well, which have themselves steadily become more capable of taking cleaner pictures in low-light conditions. SPI says its specialized low-light-level system can amplify existing light more than 85,000 times its natural brightness.
“Large pixel pitch sizes allow the chip to collect ultra extreme amounts of light and translate them photons into a clear clean bright image in very dark night scenes,” SPI says on its website. “The X27’s low light color technology utilizes specialty algorithms that allow the sensor to see in extreme low light environments traditionally unseen before.”
The X27 can even show infrared marking and targeting lasers in color, allowing individuals to better discriminate between multiple targets rapidly. In principle, SPI’s CMOS sensor could work with other existing digital optics, as well.
There is also a lower end to the technology, which involves simply adding filters to traditional image intensification systems, such as night vision goggles. ColorTAC’s CVA-14 is one such system. It is specifically designed to work with the AN/PVS-14 night vision monocular, which is in service in the U.S. military and elsewhere, both as a helmet-mounted system or as a weapon sight.
The clip-on CVA-14 puts two rotating color filters in the front and the rear of the AN/PVS-14. Ambient light then passes through the system’s intensifier tube as normal, but gets spit out in such a way that the human brain is able to decode it as if it was in “near-true color.”
True color night vision system still have a requirement for a certain amount of ambient light in order to function in color as infrared illuminators do not help bright an area dramatically even at close range. So these systems can’t work in total darkness without an additional source of visible light.
One way to help mitigate this, at least in part, is by blending the image from a color night vision camera with the one from an infrared camera, thermal imager, or another type of optical sensor, each of which may be able to detect different details. These types of fused images have the potential to be even more detailed and high fidelity, allowing the user to determine highly specific features or even writing on objects in certain cases. Creating a self-contained multi-spectral optic with color night vision and multi-wavelength infrared capability might be another option.
This doesn’t change the fact that color night vision already offers significant advantages, even if it won’t work in every single situation. Seeing in color is just what the human body is used to and so a typical individual can mentally process what they’re seeing faster with these systems. This more “natural” vision may help further reduce the change of a loss of situational awareness, vertigo, and other issues that traditional night vision goggles can sometimes cause, especially in airborne applications.
This would also provide major benefits in the future if paired with distributed vision systems on aircraft or ground vehicles, such as the Distributed Aperture System (DAS) on the F-35 Joint Strike Fighter, Israeli firm Elbit’s Iron Vision for tanks or Northrop Grumman’s Silent Watch for ships. The U.S. Army is already working on a way to blend together imagery from thermal weapon sights with the picture an individual soldier sees through their night vision goggles, which you can read about more here.
Adding color night vision to the mix would allow pilots, vehicle drivers, mariners, and individual troops to get color night vision imagery projected straight onto helmet-mounted or wide area displays. Commercial entities and private citizens might use equipment to aid in flying or driving at night, as well.
For military personnel, being able to call out targets or ask for positive identification from other nearby units based on colors in addition to other features can only help with “mental contrast,” too, speeding up and otherwise improving various targeting processes. Color night vision technology will likely only expand the overall potential of augmented reality systems on the battlefield and elsewhere as time goes on, in general.
All told, color night vision is a game-changing additional capability on top of an already revolutionary development. The goal now is to continue making the technology practical, compact, increasingly high fidelity, and able to operate even in extremely low-light-level situations.
It may not be long before the mental image we all have of military and law enforcement personnel conducting operations at night through the green haze of their night vision goggles becomes a thing of the past.
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