When getting into night vision a lot of people focus on the specs of the image intensifier tube. In this week’s episode of Friday Night Lights, I will go over night vision specs and try to explain the different generations of night vision. Hopefully, this will help inform and guide you to getting some night vision.
Generations Of Night Vision
Night vision generations are pretty straight forward. There are only three generations of night vision. Some companies like Photonis like to use some clever marketing and unfortunately it has fooled some people. Their latest intensifier tubes have “4G” as a branding tool. This has misled some people to think there is a Gen 4 of analog night vision. There is no such thing.
Generation 1: Not even once
Night Vision Generations
The first night vision devices fielded at the end of the WW II were active, and based on the anode image intensifier tubes with S-1 photocathode. Large infrared spotlights were required to illuminate targets, as the technology at the time did not allow significant light amplification to produce usable low light images.
Generation 1 (GEN I)
Developed by the US Army, the Gen 1 night vision devices were derivatives of the Gen 0 active devices, but did not require infrared spotlight to operate. Built around an S-20 photocathode with greater light sensitivity, they relied on ambient light and amplified available light around 1000x.
Generation 2 (GEN II)
The second generation night vision devices (Gen 2) represent the major technological breakthrough compared to Gen 0 and Gen 1 night vision devices. The Gen 2 image intensifier tubes are based on micro-channel plate (MCP) – a honeycomb-like wafer designed to trap photons, and increase their number as they pass through it. The Gen 2 also has an S-25 photocathode with greater light sensitivity. These improvement lead to a much brighter night vision image with higher resolution, capable of light amplification around 20,000x, allowing the devices to function in almost complete darkness and moonless nights.
Generation 3 (GEN III)
The third generation night vision devices (Gen 3) also use the Micro Channel Plate (MCP) developed for Gen 2. The main advancement found in Gen 3 night vision devices is a gallium arsenide (GaAs) photocathode, which greatly improves light amplification and system resolution. To increase the image intensifier tube useful life, the MCP in Gen 3 is coated with an ion barrier film. The coating, however, reduces the effectiveness of the MCP, as it allows fewer photons to pass through. The ion barrier is also the main reason for the “halo” effect observed during the bright light exposure. The light amplification of the Gen 3 night vision devices is also much greater, at around 30,000–50,000.
So what generations should you be focused on? Obviously, the latest is the greatest. Generation 3 is the best but that does not mean Gen 2 night vision is obsolete or a waste of time and money. What is a waste of time and money would be anything generation 1. NVGs like the Sightmark Ghost Hunters or the Armasight Spark Core should be avoided.
There was a guy who came to a local night match hoping to use these Sightmark Ghosthunters. It was a train wreck. See the video below. The light amplification of the Gen1 ghosthunters is so bad that they are pretty much useless. They require a LOT of light to work and that sort of defeats the purpose of having night vision. To give the shooter some credit, he has never shot with night vision before and only tried aiming in his house. Watch the video below he struggles to get a sight picture. Now I am not sure if it is his lack of familiarity with shooting with NODs and passively aiming through an optic or the ghosthunters are that bad that he just cannot see the reticle. Then watch as he struggles to navigate with the ghosthunters. I remember him constantly saying “I can’t see” as he struggled through half the match. It was so bad that he gave up using them and switched to shooting with a weapon-mounted white light.
Generation 2 is not that bad
Some may stick their nose up to using Gen 2 tubes. My first set of dual tube binos was an ANVIS9 build with some clean Photonis Gen2 image intensifiers. While they were not as bright as my Gen 3 night vision (I had an ITT Gen3 PVS14) it worked well enough that I could navigate in the dark and shoot with them.
Gen 2 does not perform as well as Gen 3 in lower light conditions but it is still useable. You can compensate with a little IR light if need be. It does not need to be a lot of light. An IR strobe on a helmet will cast plenty of light to fill a room.
Here is a brief comparison outdoors on a moonless night with just starlight to light up the scene. There is a little bit of ambient light from some houses a coupe thousand yards to the right where the video was taken.
While Gen 2 image intensifiers are not as good as Gen 3, there are some that are made to perform close to Gen 3 performance. Photonis’ 4G tubes are such tubes. In fact many consider them to be Gen2+. Gen 2 image intensifiers use a multi-alkali photocathode
Here is a quick video looking through a Photonis Echo and an old filmed L3 white phosphor tube. The Echo line of tubes are commercial spec.
I have noticed that Photonis white phosphor has a bluish tint to the image compared to L3 white phosphor which is a pale blue/green.
Here is a comparison of a Photonis Intens (military grade) versus a filmless L3 white phosphor tube. FYI, digital cameras do not do night vision justice when you film through them. Night vision has a very dynamic range that the eye picks up but digital cameras do not.
So you can see how Gen 2 is useable. It is not as bright as Gen 3 but totally useable. In some instances, Gen 2 image intensifier tubes can be cheaper than Gen 3 tubes. Part of it is based on the specs of the tubes which leads us into the second half of this article.
What About Night Vision Specs?
Often night vision users and shoppers get really focused on the numbers or specs of an image intensifier. There are a whole bunch of different numbers that represent what tube’s performance is, however, there are only a few that are worth paying attention to.
Figure Of Merit (FOM)
FOM is a big one but not in the way you think it is. It is big because it is the go-to number most people look for when getting night vision tubes. For lack of a better analogy, think of FOM like the horsepower of a car. The higher the number the better it performs right? But we know that is not the case. A 1,000 hp engine in a Honda Civic is not the same as 1,000 hp in a sports car or proper race car. That is sort of like night vision tubes. FOM or the Figure of Merit is a number calculated by multiplying the signal-to-noise ratio by the resolution of a night vision image intensifier. FOM number allows one to quickly estimate the general performance level of the specific night vision image intensifier.
So if FOM is not all it’s cracked up to be what else is there? For US intensifier tubes made for the government, there is something called OMNI classification. Here is a LOT of information to digest from AR15.com and David aka CJ7HAWK who we have used as a resource for looking inside an image intensifier.
Note 1. The “OMNI” data isn’t a specification. Gen3 Omni VII is a specification, but not a performance specification. Omni refers to the contract under which a tube was purchased, not the performance level of the tube. Since I published this data, it’s confused a LOT of people, so to clarify, the TUBE DATA under the OMNI headings represents the typical performance of US used tubes of the MX10160 family and represents the latest iteration of that tube. That changes slightly with Omni VIII but I’m still collecting data on that.
Note 2. ALL tubes of the SAME family (eg, MX-10160A/AVS-6 ) perform roughly the same. A MX-10160A/AVS-6 tube made in 1995 performs roughly the same as a tube made in 2009. If you find a MX-10160A that’s been made under Omni VII, don’t go assuming it performs like an OMNI VII tube. It’s still the same as the Omni IV/V tube. AND YES, they made some of these under OMNI III.
Note 3. The word MILSPEC gets used a lot, so here’s the ACCURATE DEFINITION of what it is. It refers to tubes that meet a performance specification as defined for a US Military contract. If a contract comes out for tubes from the military, then the tubes made for that contract that meet that specification ARE MILSPEC. ALL OMNI TUBES (tubes made for Omni Contracts) are MILSPEC and every tube will be made for a contract, however ANY tubes that are made to a specific specification and meets or exceeds ALL provisions of that specification ARE ALSO MILSPEC according to that specification. Hence, a MX-10160A manufactured in 2007 is technically a MILSPEC OMNI VII tube.
Note 4. To avoid the confusion this causes, you’ll notice I’ve listed some tubes only under certain contracts. This typically represents the contracts under which that tube were primarily ordered and this is how these tubes should be viewed.
Note 5. Tubes other than the MX10160 series are also included ( eg MX11620, MX11729 ) – These tubes have different performance specifications. See the tube breakdown details for more information.
Note 6. To know what tube you really have, look for the NSN in the tube data breakdowns. Keep in mind though, military records aren’t as consistent as you might imagine…
Last year the new OMNI IX specs were released.
If you want to know what your intensifier tube is and you can access it to get the numbers off of it, I recommend going to David’s website.
Sam Houston of TNVC and Greenline tactical has some good videos about resolution aka line pair for intensifier tubes.
Sam also made a video about his most important value regarding night vision devices and that is EBI (equivalent background information).
Other Considerations Outside Of Tube Specs
This is mostly for used tubes but blems in a tube should be considered when buying a night vision tube. In some rare cases, factory tubes may have a small speck and while they look like a blem it is more of a manufactured cosmetic defect than an actual blem.
Blems in an intensifier tube are usually the result of some kind of damage to the tube. This could be shock-related or burned in from a bright light source like a laser or sunlight.
The most common type of blem is a black spot that is opaque. However just because you have a black blem is not the end of the world. What does matter is where the blem is inside the tube.
Look at the image above. This is a map of the image an intensifier tube makes and where blems show up. Zone 1 is the worst but as long as the blem is small it can be overlooked.
Another type of blemish is seen above. This was actually a tube that I used to have. As you can see, while it looks pretty bad at first glance, most of the blems are in zone 3. At the bottom of the image, you can see bright spots. These are called emission points. It is a steady or fluctuating pinpoint of bright light in the image area that does not go away when all light is blocked from the objective lens. Obviously, this is much bigger than a pinpoint but it is the same thing.
Some blems are cosmetic while others are an early warning sign of potential tube death. However, that is not that common but it can happen. A tube can end up dying. They only have a minimum 10k hour life span, at least that is what Gen 3 night vision is supposed to have. Gen 2 is half that at just 5k hours of life in a tube.
Above is an odd-shaped blem. This could be from leaving night vision in a car with the daylight filter on the objective lens but it was pointed up at the sky. The sun can blemish a tube if you are not careful. If left for a long time, exposed to the sun even though it has a daylight cover, the sun can burn a line across the tube as it arcs through the sky.
The collage above is a collection of the worst blems found online. Mike R. of @Daynoodlez curated this collection of tube images. Minor blems can be overlooked if the price is right.
So, What Should You Get?
It really comes down to budget constraints and what you are using the night vision for. Some people adopt a “buy once cry once” mentality and while that is one way to go about getting night vision, it is not the only way. Just like buying firearms, you can get your feet wet with an entry-level tube that is reasonably priced. The tube is what drives the cost of a night vision device. It is the most expensive component.
If you are only using night vision for recreation and on a budget then check out some night vision companies like Steele Industries that often get used tubes and build them into PVS-14s and start at around $1500. Or go onto some night vision groups and forums for second-hand deals. Try not to focus too hard on the night vision specs. If it is Gen 3 it will work pretty well. Location and ambient light level will affect how that tube looks. Gen 2 is reasonable for recreational use or for those outside of the US. Photonis tubes are pushing the envelope of Gen 2 technology and while I have yet to see a white phosphor tube by them that beats even a filmed WP Gen 3 tube, they are decent enough if the price reflects the difference.
For the most part, having Gen 2 or any Gen 3 night vision system will positively help augment your experience at night. Unless you are spending top dollar I would not bother chasing the rabbit down the hole trying to know all the specs of a used tube. Some tubes don’t have data sheets so as long as the image is clean or has few blems and amplifies light decently, do the specs really matter? Just go out there and have fun don’t take it so seriously unless your job and life depends on it.