Throughout human history, our species has always looked for advantages in both technology and tactics. The rock became the club, which became the spear, which became the arrow, and finally the firearm. The sword was always more important than the shield, and offensive technology was always forward-thinking and progressive. Regardless of time, culture, race, or creed, humans have always looked at our resources and thought, how can we weaponize this? One of the biggest hindrances to warfare has always been darkness — sure, fighting happened at night, but up until recently, it wasn’t conducted the way we do business in this century. And today, what is more evocative of a “Tip-of-the-Spear Operator” than a NODs wearing warfighter. 

Enter image intensification, more commonly known as night vision (NV). It’s light amplification on a large scale, turning very small amounts of light photons (be they visible or infrared) into multiplied electrons, then back to photons in a wavelength that our feeble human eyes can see. It’s been around since the 1940s in its infant form, but I’ll spare you that boring lecture. First and foremost, NV was designed for offensive operations — moving to and from a point of origin to close with and destroy the enemy. This is the advantage image intensification has over other technologies that can see into and through the darkness.

Above: Many will say the “green vs. white” argument boils down to personal preference, but physiological principles indicate that the human eye can perceive greater detail through WP tubes.

This article isn’t about the tactics, techniques, and procedures (TTPs) of NV usage in a survival situation or combat zone. That’s for another night, and best left to others to explain. Here and now, I’ll delve into some of the ins and outs of NV technology and night observation devices (NODs) so that, should you decide to add this amazing technology to your kit, you can be better informed. Much like researching the materials used and the specifications on an AR-15 before you invest in a high-end gun, this will pull back the curtain and explain several things in layman’s terms. 

Green or White?

One of the most readily apparent factors of NV is phosphor screen color. A much-debated topic as of the last several years, emotions can and do run deep surrounding this subject. To understand the argument, we must first understand how the human eye works.

The retinas of our eyes have two types of photoreceptors: rods for night and cones for day. Rods are sensitive enough to perceive trace amounts of light, such as silhouettes on a moonlit night, but cannot detect color and offer low visual acuity (sharpness). Cones are far less sensitive to light, but can interpret millions of colors with much greater detail. There are three kinds of cones: red, green, and blue sensitive. Cones also give you spatial acuity, which is why you’re much less likely to stumble or stub your toe in broad daylight than you would be in a dark room. The rod and cone cells are distributed evenly throughout the retina, except in a small central area called the fovea, where there are only cone cells. The fovea is the part used for detailed vision, like reading. This is why your peripheral vision feels less precise than your direct gaze.

It takes about a thousand times more light to activate the color cone cells than it does the monochrome rods, which is why detail and depth perception are much better when using both cones and rods, instead of just rods. Rods don’t provide much detail. The goal of NODs is to take light that might only be detectable to your rods, and intensify the image enough to allow your cone cells to detect it clearly.

When using green phosphor (GP) NV we use our green cone cells, which make up only about one-third of our day vision. Humans generally don’t use rod cells with green phosphor NV systems or NODs.

With white phosphor (WP) NV (white light being the sum of all colors) we engage all three types of our day vision cones. So, WP is fully engaging our day vision mechanisms (cones) and even some of our NV mechanisms (rods). WP also has a strong blue component in the 400-nanometer wavelength range, where we engage a more substantial portion of our rod cells.

Using a WP NODs is akin to being able to use more of your brain processing power to think through and solve problems. You can certainly accomplish similar tasks with GP, but you’ll probably do so faster with WP due to the physiology involved. It delivers more light data to your brain. This leads to reduced fatigue because you’re not working as hard to gather the same amount of information. Contrast is higher and the data feed is broader.

You might be about to retort, “But Sam, the human eye can detect more shades of green than any other color in the visible spectrum!” Yeah, I’ve heard that a time or two. Here’s what you need to know about that — the dark-adapted human eye is capable of detecting more shades of green than any other color. What happens when you power up a bright phosphor screen in front of your eye? Bingo, no longer dark-adapted, so that factoid goes right out the window. In scientific terms, there’s a chemical compound in your eye called rhodopsin that’s produced at night. Once exposed to bright light, it photo bleaches.

Colorblindness is generally a genetic mutation of one of (or a combination of) the red, green, or blue cone photoreceptor cells in your eyes. True color blindness genes are carried on the X-chromosome, which is why it’s spread from grandfather to grandson. Very rarely is it expressed in women. If you’re truly colorblind, then that can affect your choice a bit, but WP probably still comes out on top for the reasons I outlined above. If you can’t see green, then WP is even more clearly the choice. If you can’t see red and blue, then maybe GP is the better choice for you.

That said, much of this argument still comes down to personal preference for many people. Nothing compares to trying both GP and WP in-person over an extended period of time to literally see which phosphor color one prefers. The physio/neurological basis for the detail, contrast, and fatigue advantages of WP are true regardless, but remember this as well: Some people are born with more of one type of photoreceptors than other folks. The same can be said about rods, as some people’s natural unaided NV is better than others, so genetics can come into play a little. Finally, individual tube and NODs specs and NV generation are important variables to consider. As we’ll explain momentarily, these issues need to be taken into account independently of phosphor choice for a truly useful comparison of WP versus GP. 

Next, we must get into the nitty-gritty of the tubes’ actual performance. Think of tube specs as what a dyno readout says about an engine’s horsepower and torque. In my opinion, the following are the five most important tube data points. It should be noted that there are others, such as luminance gain and high light resolution, that aren’t included due to their secondary nature as NV tube spec data points. This is a reference for U.S. Gen 3 systems and data sheets.

Photocathode Sensitivity: Photocathode Sensitivity is the PC’s ability to convert Photons to electrons. A higher PR usually corresponds to good SNR numbers. The minimum is 1,800 for the OMNI 8 contract. 1,800 is good, anything above 2,000 is very good. It matters a great deal to have properly matched photocathode numbers for a dual-tube system, +/- 100 is generally the range I adhere to when building/assembling dual-tube systems. This will prevent one tube from appearing noticeably brighter than another while in operation.

EBI or Equivalent Background Illumination: This is the amount of light you see through NODs when an image tube is turned on, but no light is on the photocathode. EBI is affected by temperature; the warmer the NV device, the brighter the background illumination. EBI is measured in lumens per square centimeter (lm/cm²). The lower the value the better. The EBI level determines the lowest light level at which an image can be detected. Below this light level, objects will be masked by the EBI. The lower the better. For example, this will determine the contrast of a ridgeline against the sky behind it. EBI is an often-overlooked data point, but is a very important one — many times the most important in terms of detecting and/or differentiating objects.

SNR or Signal to Noise Ratio: Plays a key role in NV performance. The role of the micro-channel plate, SNR is the unit’s ability to transfer a strong signal from input to output and is usually referenced as a ratio (19:1, for example). This measures the light signal reaching the eye divided by the perceived noise as seen by the eye. The higher the difference between the two numbers, the better. As the light level drops, scintillation (visual noise or graininess) will be noted sooner on a tube with lower SNR versus one with higher SNR.

Center Resolution: Screen resolution measured in line pairs per millimeter (LP/mm). The higher the better. Usually listed in line pair increments of 57, 64, 72, 81, and so on. When a center resolution is listed, the line pair measurement could in fact be higher, but not high enough to cross the threshold of the next listed LP resolution. For example, a 64-line pair listed tube could in fact be as high as 71-line pairs, but because it doesn’t meet or exceed the 72 limit it cannot be listed as such.

Line pair resolution is generally not as important as many people make it out to be. For example, the human eye cannot tell the difference between a 64- and a 72-line pair when viewed through a 1x system such as a PVS-14. However, when used or viewed in clip-on NODs alongside a magnified rifle optic, a higher center resolution is preferred and often noticeable for better resolution/image quality.

Halo: Bloom or halo when looking at light source, or the ability to control the bloom when viewed. The lower the value the better. Objects can be masked or hidden behind bright blooms of light in tubes that have higher halo values. Lasers can also have more apparent bloom off certain objects in some tubes as opposed to others due to this attribute. A high halo value can contribute to a lowering of tube resolution (high light res) thus affecting what can be seen/detected by the user.

Above: Halo comes into play when looking at a light source that has the potential to overload receptors in your NV tubes. High-quality tubes will be able to better modulate incoming light from secondary sources like lights and illuminators.

FOM or Figure of Merit: This is simply center resolution multiplied by signal to noise ratio. The higher the value the better. It’s a quick, down-and-dirty way to determine the performance of a tube, mostly for export purposes set forth by the U.S. State Department. Because FOM measures only two data points, it’s not the be-all and end-all of a tube’s performance. In other words, you could have a low to average FOM tube that can, in certain lighting conditions, outperform a tube with a higher FOM, or at least match its real-world performance. EBI, photocathode sensitivity, and halo are three very important data points to take note of when looking at a tube. 

Are Tube Specs Important?

This is an often-asked question and the short answer is maybe, maybe not. If you’re using a NODs as a stand-alone unit without supplemental infrared (IR) laser/light energy, such as for astronomy purposes, then a tube with high data points overall is going to do more for you than a lower performing system. Notice I didn’t say FOM — as I stated previously, FOM is not the be-all and end-all in a system, though it should be noted. 

Now, can a human tell the difference between a 30 SNR tube and a 37 SNR tube? Not in all but the darkest of lighting conditions. Even then maybe not, depending on the viewer’s eyesight. You can chase NODs tube specs until you’re blue in the face, and in reality gain nothing but wasted time and energy. Go with what I list below as a template for tube specs, and try not to get too wrapped around the axle about them.

For a thin-filmed Gen 3 system some good numbers to go off of as of the writing of this paper would be as follows:

• Photocathode: 1,900 or higher
• EBI: 1.5 or lower
• SNR: 26.0 or higher
• Center Resolution: 64 LP/mm
• Halo: 1.0 or lower
• FOM: 1728 or higher

Moving onto an unfilmed system, good numbers to go off of are as follows:

• Photocathode: 2,000 or higher
• EBI: 1.0 or lower
• SNR: 30.0 or higher
• Center Resolution: 64 LP/mm 
• Halo: 0.8 or lower
• FOM: 1920 or higher

If you have NODs that exhibits most or all of these numbers, you possess a very solid performing system.

If you’re using supplemental IR lighting in conjunction with NODs for detection and targeting, then that’s going to boost the capability of a lower performing system significantly to the point where tube specs are going to matter less and less. This is especially true at close ranges under 100 meters. Put simply, a powerful laser/illuminator is going to do more for you than tube specs will almost every time. 

Ultimately though, it comes down to training with your gear and training your eyes how to observe your environment. As you spend more time using NODs and acclimating your eyes to them, you’ll be able to see things with a lower performance system than folks who are untrained and unaccustomed to using a higher performance system. If I was behind the wheel of a high-performance Formula 1 car, a skilled racecar driver could still beat me around a track in a street car simply because I don’t have the experience to make the most of that highly tuned vehicle.

The opinions expressed in this writing are mine and mine alone. Technology advances as time goes on, so in the future some (or much) of what’s said is sure to change and/or be updated. If you’re seeking further info, I welcome you to watch some of the informative videos I have on my SilentSolutions YouTube channel or attend a Greenline Tactical class taught by me and Don Edwards. 

About the Author

Sam Houston is a 10-year Veteran of the U.S. Navy, where he flew onboard P-3C Orion surveillance aircraft as a flight tech and sensor operator supporting combat operations in multiple theaters. Transitioning to the civilian sector, he became a qualified UAV operator/maintainer on RQ-27’s, logging over 2,000 hours supporting conventional and Special Operations Forces in Iraq and Afghanistan, both on the battlefield and remotely, as well as a thermal and electronic surveillance sensor operator on RC-12 aircraft supporting U.S. interests overseas. He’s currently in the Florida National Guard as a forward observer. 

Sam owned and operated a NV hog hunting outfitting guide service, taking clients into the Florida swamps and forests to search, locate, and harvest feral pigs with the aid of NV and thermal optics. In 2015, he was hired by TNVC and ran the NV Goggle build and repair programs and continues at TNVC as the special programs manager and a night vision technical advisor. Additionally, Sam helps run the Night Fighter NV Training Program with Don Edwards at Greenline Tactical, and works for John Lovell at the Warrior Poet Society as an assistant instructor.

MORE ON NIGHT VISION

• GBRS Group: Shadows that Bite.
• Night Vision Helmet Setup Guide.
• Night Vision 101.
• Sionyx Aurora Pro: Color Night Vision Review.

A long time ago, on an Army base far away, I began my military career training to be a Cavalry Scout. This reconnaissance-oriented occupation was all about observing the battlefield undetected, whether we were in a vehicle or traveling on foot. Of all the tactics we were taught, none were as important as leveraging every asset at our disposal to our advantage, including the time of day. Scouts learn to operate under the cover of darkness to an extreme degree. After nearly a decade within the ranks, I had the opportunity to use and abuse multiple generations of night vision optics under some of the most austere conditions. A few of those optics appear in the movies, but some of them required non-disclosure agreements. I recently had the opportunity to evaluate commercially available digital night vision optics in the form of the Sionyx Aurora Pro.

Above: Nestled snugly in a near-impermeable case, the Sionyx Aurora Pro has more than enough protection to survive strong impacts and adverse atmospheric conditions.

Affordable Versatility

Sionyx uses digital night vision technology — as opposed to the analog tubes used by most of its competitors — to give you a view of the midnight realm in full-blown technicolor. After spending years staring at varying shades of green or gray, I was eager to get my hands on a system that could revolutionize how we interact with the dark.

Above: When the Trijicon MRO and Sionyx Pro are properly aligned, nighttime range training becomes a walk in the park.

If you’ve ever looked at what it costs for a third-generation night vision optic or a FLIR thermal optic, you’ll quickly learn that it’s not an inexpensive purchase. For thousands of dollars, you can have the latest analog, monochromatic optic. Now look at the top model that Sionyx has to offer, just south of a grand. They even offer financing for those of us who don’t have fat stacks of Benjamins lying around. Models with fewer features are even less expensive, making Sionyx a widely accessible option for those who need to see in the dark.

Options. As if Seeing in the Dark Wasn’t Enough …

There are several models to choose from (Aurora Sport, Aurora Black, Aurora, and Aurora Pro) each with their own pros and cons. Every optic is water- and dust-resistant, and submersible down to 3 feet for 30 minutes, which means any Sionyx optic is safe to use in the most torrential downpours. A clear, scratch-resistant lens cover keeps your view crystal-clear without having to worry too much about abrasions, and each model has been drop tested from 1 meter onto concrete. Durability in harsh conditions is great, but how do these digital optics differ from their analog counterparts? 

All models have built-in memory, because they not only allow you to see in color in the dark, they also double as a digital camera which has settings comparable to a DSLR, including the ability to adjust your aperture and shutter speed. An accelerometer will let you take panoramic pictures in landscape or portrait modes. Sionyx optics will also film video at 720p with an adjustable frame rate of up to 60 frames per second. Remove the micro OLED 1024×768 eyepiece, and you’ll be able to increase the storage capacity with your choice of MicroSD card. I recommend choosing a high-quality MicroSD with fast transfer rates. 

In addition to these standard features, the Black, Aurora, and Pro models offer additional benefits. They are weapons-rated up to .223/5.56, and both the Aurora and the Pro feature GPS, compass, metadata, and accelerometer recording. The Pro tops out the memory features with 256 gigabytes of onboard memory, and a 32-gigabyte MicroSD card. Sionyx also offers an attachable IR light that enhances visibility through the optic, as well as a Picatinny rail adapter that allows you to mount the optic to your favorite weapon. 

Above: Jeff Stroud (aka Freebird) eagerly prepares to engage targets previously obscured by the dark.

The applications for a night vision optic dramatically increase when it’s paired with the right mounting options. With the use of a Wilcox helmet mount, rail adapter, and your choice of tactical head gear, you can walk around with this optic hands-free. Ram Mounts makes ruggedized device cradles, and with the right one, you can attach the optic to the handlebar or storage rack of an ATV or snowmobile. 

Impressive Performance

My first impression of the Sionyx Aurora Pro was the protective polymer case in which it was delivered. If you’re familiar with Pelican cases, you won’t be disappointed with the case Sionyx provides — it’s durable, sealed against water and dust with a one-way pressure valve, and features snap latches and a carry handle. Inside, the optic is nestled snugly in molded polyethylene foam. Two spare batteries and a neck strap also accompany the optic, but I was surprised by the absence of a manual. Figuring out how the system works on my own seemed easy enough, but I did contact
Sionyx about it. Their team promptly emailed a digital version of their operating manual along with a list of recommended optimal settings.

Above: Capable of macro photography, Sionyx allows professionals to geotag small but important details.

Charging the optic took less than an hour to bring all three batteries to their full capacity. When first powering up, note that there are three viewing settings — Day, Twilight, and Night — which can be set with a quick turn of an adjustment ring on the front of the optic. Inadvertently using the wrong setting will not harm the optic’s sensors (another benefit to using digital night vision), and the transition is nearly instantaneous.  

Above: Poorly lit suburban areas become brilliantly exposed.

Viewing the surrounding landscape outdoors is phenomenal, but I also wanted to see how it stacked up to being indoors with nearly zero ambient light. Some of my military scout training included many years of urban combat, which is a cool way of saying “stumbling through pitch black buildings using optics that afforded less-than-adequate depth perception.” My first impression of the Aurora Pro Night Color mode didn’t provide the clearest picture, but the device has several built-in “Night Tone” viewing options, such as Night Color, Green, and Grayscale, all easily interchangeable with the push of a button. Grayscale, after adjusting the focus and contrast, seems best for pitch-black indoor conditions, with very little loss of depth perception. 

If you’re familiar with some digital photography basics, you’ll enjoy the customizability of the Aurora Pro’s camera settings, which allow the shutter speed, brightness, contrast, zoom, and focus to be adjusted. The adjustments are straightforward and simple to understand. I was pleasantly surprised at how well the optic could focus for short-range macro photography, and the panoramic option works better than some phones I’ve owned in the past.

Wi-Fi is featured on every Sionyx model, which allows you to utilize an app available on iOS and Android devices. This app lets the user see what the optic is looking at in real time, adjust the optic’s settings, take pictures, and record video remotely. Sionyx chose Wi-Fi instead of Bluetooth because it offers longer ranges, faster transfer rates, and less latency. Ideally, you’ll want to have as unobstructed of a line of sight between optic and device to improve connectivity range and quality. 

Admittedly, app usage may present the optic’s only downside. The app can tend to be quirky if the connecting process isn’t performed exactly right, and it can be frustrating to troubleshoot. Along with wireless communication comes a small amount of lag, which seems to be one of the biggest complaints when sifting through reviews on the app store. But remote and mobile wireless observation with a little lag is a fair compromise over being tethered to a cumbersome hard-wired device.

Above: Creatures of the night can no longer hide in the darkness.

Wi-Fi capabilities open a realm of clever uses for the optic. For the purpose of surveillance, placing the optic discreetly within 20 to 30 feet will give the user the advantage of viewing the intended target while being able to monitor from a concealed location. A sensitive onboard microphone will pick up and record quiet noises many digital cameras ignore. Even more impressive, and my favorite application so far, is mounting the camera to an ATV and going partial blackout mode. Pair the optic to your phone and you can see farther down the trail than you could by running on headlights alone. With the proper Ram Mount setup, your ATV or snow-machine can be as stealthy as the Batmobile. I should caution you though: Because of the wireless communication latency, the faster you travel with this optic, the less time you’ll have to react to sudden changes. This just means you need to ride/drive with caution and be aware that what you’re seeing may be a few tenths of a second behind.

A Night at the Range

To test its capabilities on a firearm, I reached out to the guys at 906 Tactical and gave it a run at a night range. Weather conditions at the range were typical of a January night in Upper Michigan — 15 degrees F, overcast, and as close to pitch black as you can get in the snow. Jeff Stroud, the owner and instructor of 906 Tactical, helped with testing, and was able to clearly identify silhouette targets at 150 meters and rough shapes beyond 200 and using Night Color mode. Picatinny rail mounting was a breeze, and before long we were ready to ring some steel.

Above: Utilizing a head mount keeps hands free for light-sensitive repairs or pest control.

Technical specs of the Sionyx Black, Aurora, and Pro have the optic rated for .223/5.56 weapons systems, and 906 Tactical provided several demo guns. First up was a silenced Daniel Defense Mk18 with Trijicon MRO sight, mounted high enough to be level with the center of the Pro’s objective lens. After some adjustments to the Aurora, we had a clear view of targets between 50 and 150 meters, and full use of the MRO’s 2-MOA dot. The .223’s recoil had no effect on image stability. There was a brief flash of washout in the Sionyx optic after shots were fired, but it recovered rapidly. We even ran it mounted to two versions of a Galil Ace, in 5.56 and 7.62x39mm, equipped with a Holosun 510c reflex sight and an Athlon 1-4x magnified optic. 

If using night vision on a weapons system, I recommend pairing it with a holographic or dot sight that’s capable of projecting in green light and has a night vision setting. When using the Sionyx with a Holosun 510c, I noticed the green reticle was less intense and didn’t overwhelm the targets with its brightness. When using a magnified scope, make sure you can place the Sionyx Aurora in front of the sight’s objective lens. This will allow you to use the Aurora’s zoom capabilities cumulatively with the scope and get a much closer look at your target. Just be aware that, without a rubber eye cup, the green indicator light on the side of the optic does give off a small amount of visible light.

NV Isn’t Just for Professionals

Many people associate night vision with professional tactical teams. While that’s certainly an effective use for night vision, there are many others that could benefit from having an affordable night-capable optic.

Every year, I hear another story about someone who was out hunting until sunset, got lost, and ended up with a nasty case of hypothermia because they spent the night getting turned around trying to find their way back. With a digital compass and onboard GPS, the Sionyx could be very helpful in such a situation.

Above: From Left to Right: A scene in natural ambient light; “twilight” mode; night grayscale; night color.

Say a storm rips through your neck of the woods and you must go out to assess the damage. Just take a photo with the optic, and you’ll have GPS coordinates to the location of said damage. You can then provide photos and exact coordinates to responders or repair crews.

Anyone familiar with trail cameras understands how frustrating it can be to capture an image or video of a species you’re after. With a Sionyx optic, you could record your own high-resolution observations with metadata included.

Above: ARs are great to shoot under normal conditions, but being able to train under the stars elevates the experience to a new level.

Individuals could utilize it for personal and home security to survey a yard, large property, or even look downstairs into your living room. Late-night thrill-seekers could use it for recording their adventures. Medical personnel arriving at the scene of an accident in the middle of the night could quickly find someone in need of attention. The point I’m trying to make is that having a quality night vision system that’s this affordable opens so many opportunities that were previously unreachable.

Final Thoughts

Based on my previous experiences, I can say that Sionyx devices offer a substantial nighttime capability to just about anyone who has a need or want, with more features and a lower price point than the majority of conventional night vision devices. Affordability and versatility are often key decision-making factors when choosing a tool or piece of equipment to purchase, and Sionyx offers both. If you’ve been hesitating to invest in night vision because of the prohibitive costs associated with it, Sionyx night vision optics might be just what you’ve been waiting for. 

Sionyx Aurora Pro

Above: Ram Mounts offers the right hardware to mount the optic to your choice of off-road vehicle.

Included:

• Aurora Pro color night vision camera
• Hardshell waterproof case
• 2 camera batteries
• USB charge/data cable
• 32GB MicroSD card

MSRP: $999
URL: www.sionyx.com

Shop Sionyx at Optics Planet

[Editor’s Note: It’s worth mentioning that Sionyx Night Vision can be found on Big Daddy Unlimited. Read about it here on RECOILweb. The Savings on a Sionyx Sport, will pay for more than a year of BDU, and the unit will cost about the same as a used Glock.)

-Click here for a Big Daddy Unlimited Trial month for 99 cents.-

More on Night Vision

• How to set up your Rifle for Low-Light/No-Light Conditions.
• Night Vision 101.
• GBRS Group: Shadows that Bite.
• Night Vision Helmet Setup Guide.
• Night Vision Goggles: A Double Primer Comparing Two Models
• Unobtainium Gear Active Night Vision Recording System: Taping what you see.