Night Vision vs. Thermal Vision
What you can’t see CAN hurt you!
By: Devin S. Standard
|An enemy target in both thermal and standard night vision.|
A crash in the night, your heart goes THUMP! We humans have an innate fear of darkness programmed into the firmware of our DNA. It isn’t imagined. What you can’t see in the dark CAN hurt you. The cover of darkness has been the friend of the predator, the criminal, the terrorist, the Devil Himself, which is why night vision manufacturing is now a billion-dollar business. Night vision technology has come a long way in the last ten years. Gradually the prices have come way down. What used to be available to just the military is now within the financial reach of civilians and law enforcement.
I recently had the opportunity to do some night operations training down in North Carolina. Wow! Whether running and gunning with, helmet-mounted goggles, engaging targets with a night vision scope, or sending .308 projectiles down-range with the aid of a thermal scope, the ability to see in the dark delivers a super-human like feeling of invincibility! Hundreds of thousands of night vision devices are giving our fighting forces a significant advantage on foreign battlefields this very evening. Tens of thousands of law enforcement professionals are currently using night vision to help keep the streets safe. You need to get some of this technology too, and now you can.
Night vision generally works in 3 different ways:
- Image Intensification (I2) – This is the most common type of night vision technology. It works, in the darkness, by capturing the tiny amount of available ambient light coming from the moon, stars and artificial sources. I2 also captures the lower end of the infrared light spectrum, that type of light is usually imperceptible to our eyes, but is present. The device captures these light sources, amplifies them thousands of times via an electronic “tube”, and projects the image on a viewing lens. The images appear a grey green color and there is a nice level of detail rendered with the latest, GEN III and GEN IV technology. You can even see through windows with I2. Note: There must be some light, I2 will not work in total darkness, such as in caves.
- Thermal imaging – Thermal technology operates not by aggregating light; but by capturing the “heat” emitted by all object/persons. This “heat”, is literally the upper portion of the infrared light spectrum. Hot objects, like running machines, people and animals, emit more of this “light”/”heat” than cooler objects like rocks, trees or buildings. The image appear in gray-white or gray-black depending upon your preference, as the polarity can be adjusted so heat can either be shown black, or white. The thermal images are crisp enough to clearly distinguish facial features within 25-30 meters. Thermal imagers are commonly called thermal cameras, thermal sights, thermal monoculars or thermal binoculars. Note: Thermal imaging technology does not allow you to see through windows, or under water, because the “heat” is reflected back. In fact, you will see your body heated reflected back off the surface.
- Fusion– Thermal imaging and Image Intensification (I2) technology have now been combined in single devices so both the infrared energy and the ambient light are captured. This allows the operator to now identify people and objects in almost all low-light/no-light environments. Now, thanks to fusion technology, Osama can’t hide in the total darkness of a cave, we can see him through windows, fog, etc. Fusion can be operated as an (I2) device, as a thermal imager, or in a combination mode. I recently got to try a $50,000 Fusion Goggle and I have to say,”wow, you can see someone’s soul”! There is even a mode in which there is an electric green wire frame outlining people. This is a great aid in targeting. You are the Predator! Sorry I cannot show you a fusion image.
|Night vision operation.|
These three technologies are regulated under International Trafficking in Arms Regulations (ITAR). This means, as a non-felonious US Citizen, you should be able to purchase them; but you may not export them. “Exporting” includes demonstrating them to non-US persons, agents or firms, as well as not leaving US waters upon your boat. There may be exceptions. Check with your legal counsel. Thank God, I am not a lawyer.
|Weapon mounted thermal.|
- NVD– Night vision device
- NVM– Night vision monocle
- NVG– Night vision goggle
- I2– Image intensification
- MCP– Micro-channel plate
- IR– Infrared
- FPA– Focal plane array
Now that you’ve decided you want to negate the night, it’s time to decide what to buy. First of all let’s look at I2 products. They come in several different generations: GEN 0, GEN I, GEN II, GEN III and GEN IV. As with ammunition’s +P and +P+ varieties, there are some additional identifiers with night vision devices. I am going to forego those details until a future column.
Devices also come with names like PVS-7, A/NPVS-14, etc. Those are simply US military logistical codes for identifying various products. The A/N stands for Army/Navy and the PVS stands for Passive Vision Site. The most common one you will see on today’s battlefields in the AN/PVS-14, or PVS-14, which is a GEN III night vision monocle which can be hand held, weapon, or helmet mountable,
|Soviet era nightvision.|
GEN 0: They were developed by AEG for the German army in the late 1930’s and several other firms for the US during the same time period. These early devices used large infrared illuminators to highlight the targets and a “tube” consisting of an anode and photocathode to create the image. The resolution was not great. You wouldn’t want to pay for one of these, except for potential collectability.
GEN I devices became available during the Vietnam War era. They were essentially GEN 0 with technology enhancements, allowing the utilization ambient light instead of artificial infrared light. The light is amplified by about 1,000 times by a GEN I NVD. The technology improvements have made them significantly smaller and lighter than GEN 0; but their 1960’s photocathode based image intensifiers were still large and expensive, and required bright starlight or moon light in order to function well. You most likely have heard the term “Starlight Scope”, and starlight was, and is, key to the functionality of GEN I night vision devices.
|Vietnam era nightvision.|
There have been steady refinements in miniaturization, optics and ruggedness of these devices. Now you can buy a fairly decent Gen I night vision device for less than $250. With it, you should be able to observe targets, with pretty good clarity, out to about 75 Yards. There will be a small amount of electronic whining when a GEN I device is on. Additionally, there will usually be a bit of distortion along the periphery of the image, and the eyepiece will momentarily keep glowing after shutting it down, similar to an old fashioned TV. Overall, a pretty good, cost effective solution for home defense for those on a really tight budget.
GENII devices are widely used by law enforcement and professional operators. They are even more robust than GEN I NDVs. GEN IIs are further enhanced by the inclusion of an MCP, or Micro-channel Plate and an even better photocathode tube, and S-25. The MCP goes directly in front of the photo cathode and acts as an electron amplifier. The thousands of additional
|Gen II NV Monocular, Hand Held, Helmet or Weapon Mountable. $2899 Retail|
electrons, released by the MCP, deliver the user a much brighter and crisper image, particularly around the edges. The light is amplified by about 20,000 times. Also, the effective range of the GEN II is increased to about 100 yards in pitch black conditions, a 33% enhancement over GEN I units. Caution: these can be damaged by pointing directly at bright lights. GEN II devices typically cost $500-1000 more than a GEN I NVD. GEN II night vision is a solid solution for the responsible homeowner and law enforcement officer.
GEN III NVDs are the good stuff in terms of night vision tools. Costing about $3000 and up, they have been improved by further advances in material science. Significant additional enhancements have been made in their electronic guts. The Photocathode has been made with Gallium Arsenide and the GEN II Micro-channel Plate (MCP) has been updated by coating it with a highly precise ion barrier. This combination results in an even brighter and crisper image than was possible with GEN II. The light amplification is also improved to around 30,000-50,000 . An operator using a GEN III device will enjoy being able to identify and monitor activities at 150 yards or more in nearly pitch black conditions. There is only one minor shortcoming I’ve found when evaluating GEN III NVDs. I noticed a bit of a green halo when looking at, or around, very bright objects (street lights). This minor green halo might cause the observer to miss some of fine detail at distance, such as if a subject is holding a small gun or knife, when the subject is standing in front of a light source. Every cop or soldier knows these items are
|Gen III NV Rifle Scope. $3,000 Retail|
difficult to detect as a distance in bright daylight, so caution is always recommended when dealing with potential threats. If you can afford $3-4,000, GEN IV is a technology choice for both home-defense, and professional high-speed, low-drag operators. (I fantasize about have a master power switch in my bedroom and putting on my goggles! (yes I know I’m not supposed to clear the house alone)
GEN IV gets complicated. There is currently no agreement among the military, law enforcement and the manufacturers on what to call these excellent devices. They are known by any of the following names:
- GEN III+
- GEN IV
- Filmless & Gated I2
|Gen IV NV Binoculars $8000 Retail|
Let’s call them GEN IV for our purposes. GEN IV NVDs are state of the art. These offer excellent viewing up to 1,000 yards under the right conditions due, in part, to GEN IV’s new gated, filmless technology. Another significant enhancement is the installation of an automatic gated power supply. This development precisely and quickly regulates the photocathode voltage, allowing the NVD to instantaneously adapt to changing light conditions. Meaning it rapidly adjusts as you move among conditions with differing levels of light.
Another change is that the ion barrier film has actually been removed from the system, allowing significant increases in target identification at longer ranges, and, under very low light conditions. The signal to noise ratio is significantly increased as a result of the optimized filmless MCP, this yields better image quality in extremely low light conditions. What that means is that a significantly higher percentage of electrons are properly harnessed into image creation as opposed to “noise”, or pixilated distractions from the image. The contrast adjustments are better too, making the device perform better under all light conditions. Even the previously discussed “halo” is almost non-existent. The downside to removing the ion barrier means a diminished device life expectancy, from 20,000 hours to 15,000 hours mean time between failures. This equates to a reduction in mean life expectancy from 1666 nights service life to 1250 nights. Most manufacturers give a solid 2 year warranty, so I am not overly concerned. I really hope I won’t be tasked with over 1,000 night missions. If I am, someone else is paying for my NVD.
How good are these? Some SWAT guys and I recently evaluated a unit in Wyoming. We had no problem identifying subjects at 600 yards, typically an effective range for .223. I’d say on ops with a .338 Lapua, .308 or .300WinMag, you could project your will to the 1,000 yard range, under the right conditions, without the subject even knowing you were in the vicinity. A Gen IV NVD is on my Christmas list. Hopefully my wife will win the lottery.
|Panoramic NV Goggles Priceless|
Thermal night vision devices rock. The prices are coming down quickly; but they are still really expensive, $5,000 and up for a good hand held and $11,000 and up for weapon mountable versions. As I was recently in the employ of a defense contractor, I had the opportunity to send a fair bit of lead downrange, targeted with by a variety of thermal weapon sites. I also got paid to extensively evaluate several hand-held thermal imaging models. For the purpose of this article, I am going to ignore vehicle and aircraft systems and focus entirely on man portable systems, those with which I have experience.
All living things generate their own heat and will produce a signature, while inanimate objects will absorb solar radiation as well as heat from artificial sources, and produce a thermal signature. Thermal imaging works by capturing the infrared energy that is reflected by all bodies containing heat, passing it through a thermal core (microbolometer) onto a Focal Plane Array (FPA) via an advanced image processing algorithm. Just as with computers and cameras, they are rapidly getting smaller and more powerful. The better devices are extremely sensitive, and currently able to detect differences as small as .01 degrees Centigrade. This means you can see the residual heat left when someone has touched a wall or walked across your carpet until the heat dissipates, wow. You can see video of this on Youtube.com. Here is a good example: http://www.youtube.com/watch?v=d4vZKGq3lE8. Just type in “thermal image” if this linked film isn’t running for some reason. There is quite a collection of videos.
|The reticicle of a weapons mounted thermal.|
Thermal devices capture the heat information from all objects, including the ground, rocks, trees, etc., within its field of view. The device’s processor then creates an image for you to see. People and animals can’t hide their body heat, so users equipped with thermal devices can easily identify them, their foot, hand or paw prints, etc. Thermal imagers work the same during the day, or at night, so the tool can be used for target observation 24/7/365. Unlike the previously discussed night vision, which requires minimal light and an un-obscured line of sight, to the target, with thermal imagers, you can:
- See people in total/absolute darkness
- See people through smoke, dust, and light fog, light rain and light snow.
- See people through camouflage and foliage in any lighting conditions
- See more – and see farther – than with other low-light night vision goggles and cameras.
5 things distinguish thermal cameras from one another;
- Resolution is expressed as: 160 x 120, 320 240, and 640 x512. The higher the number, the larger the number of pixels/unit of area. The greater the number of pixels/area, the better the accuracy of temperature measurement yielding clearer, more precise pictures. The resolution race is on among various manufacturers, and crisper images are today’s standard as opposed to the “blob cams” of the 1990’s.
Thermal Weapon Site $15,000
- Refresh Rate, expressed in Hertz, is another way of saying frames/second as in movie film. The higher the better. A 50/60Hz devices will refresh at 50/60 frames/second and will give full motion video, just like watching TV. Slower refresh rates will exhibit some drag, and the images may be jumpy, or have some blurring if the user turns the device quickly. Only low refresh rate thermal imagers may be exported without going through the Department of State paperwork. Please be careful, we don’t want the good stuff in the wrong hands.
- The leading manufacturers now produce high performance thermal cameras with color images. The color does not match human visual reality; but small differences in temperature. Once you get used to the artificial color palette, this is proving ever more popular. It is nice for clearly distinguishing guns on a person’s body versus the more common grey scale, black & white displays.
A parking lot with thermal vision
- Ruggedness: Hand held Mil-spec thermal cameras are generally built to be waterproof to 66′, to withstand extreme changes in temperature and even multiple drops from 4′ onto concrete. Weapon-mountable, Mil-spec thermal sights are designed to stand up to weapon recoil as well.
- High-end thermal cameras also have the ability to measure target temperatures. This is called Thermography. This is a great tool for knowing whether a machine is running in an optimal operating temperature range, whether a suspect is sweating or feverish, etc. I’ve heard that road side bombs clearly have a different temperature/color than the dirt, debris or other material under which they are hidden. I have no personal experience with this however.
Both night vision and thermal imaging device come in a variety of form factors.
NVD’s and thermal imagers come in various configurations:
- Monoculars – Helmet-mounted, Weapon mountable (typically mounts in front of day optic), and Hand held
- Dedicated rifle scope
- Panoramic goggles
|A parking lot with thermal vision|
My recommendation for the non-military user is to buy a hand-held monocular unit which can be head-mounted, helmet-mounted or weapon-mounted. This way you have the flexibility to configure it in the manner most suitable for your mission requirement. For home defense, for example, helmet or head mounting makes a lot of sense. You hear the bump in the night, put it on and do what you have to do, without your Surefire giving away your position. Also, the head/helmet mounting means your hands will be free for other requirements. Additionally, I would look for a product from a reputable manufacturer such as Flir, Trijicon, ATN, Meprolight, or other, verifiable, military suppliers.
Good luck with the zombies.
About the Author: Devin S. Standard is an NRA pistol instructor, an accomplished martial artist, a hunter, a defense industry executive and a family man who has lived, worked and traveled extensively in Europe, Latin America, Asia and Africa. He has survived several disasters, one war, trekked Everest, ridden 4 bulls and crossed the Sahara on a motorcycle. He resides somewhere in the Live Free or Die State of New Hampshire.