Ah, yes. To Gucci, or not to Gucci, that is the question. If you're reading this blog, and you've found us, then you already know that L3 Harris's Unfilmed White Phosphor tubes are the cream of the night vision crop. The tip of the spear. But there's a lot of myth, conjecture, and downright misinformation surrounding them as well. Plus, they make up a small portion of the overall tubes on the market, so what's happening with all those other thin-filmed and thick-filmed tubes?
Let's take a look at the facts between filmed and unfilmed night vision intensifier tubes. Not the marketing, not the hype, not what Instagram trap l0rdz are telling you... just the facts.
What is Night Vision "Film"?
Great f*cking question, and one we don't see even talked about too often in the filmed vs unfilmed debate. First, to understand the technical side of all this, we recommend checkout out our How Does Night Vision Work? blog.
In short, when the photocathode converts light energy (photons), into electrical energy (electrons) to be amplified, there can be stray ions sent towards the micro-channel plate (or MCP, what amplifies the electrons) as well. These charged atoms are damaging to the MCP, which is why the film is typically called "Ion Barrier Film". It's one of the determining factors in Gen 3 night vision devices, and the reason that Gen 3 devices have double or more of the service life that Gen 2 does.
So if film is a good thing, and if it has to have film to be a Gen 3 tube, what does that imply about "Unfilmed" or "Filmless" night vision tubes? Well,... it's complicated. For a full understanding, let's take a look at the chronological advancement of Gen 3 night vision, and how filmed vs thin filmed vs unfilmed night vision came to be, and advanced.
Night Vision History
Generation 3 Image Intensifiers can be broken down essentially into three categories in relation to their Ion Barrier Films, and these categories can be separated by a timeline of the advancement in night vision technology over the years. Filmed, Thin Filmed, and Un-Filmed (or Filmless).
Filmed Tubes
Ion Barrier Film and Gallium-Arsenide layers in photocathodes is what moved night vision intensifier tubes from their 2nd Generation to the 3rd, and brought night vision into the modern age. The Omni I contract was issued in 1982, and the tubes really weren't that much better than Gen 2 night vision of the time. There were small advantages, but nothing significant. Nowadays these earlier tubes are referred to as "thick filmed tubes". They are still produced, but in much more limited numbers compared to unfilmed and thin-filmed tubes. Now that there is no longevity advantages to the thicker film, there is no benefit to these tubes. However, that doesn't mean that thick filmed night vision tubes aren't fully serviceable and usable. For the majority of recreational users, these tubes will absolutely get the job done.
Unfilmed Tubes / Filmless Tubes
Oh, did you expect to see Thin Filmed before Unfilmed Tubes? Believe it or not, filmless technology actually pre-dates thin-filmed technology. And this makes sense, considering that Gen 2 utilized an unfilmed micro-channel plate.
The first unfilmed tubes were produced by Litton, and partially filled the Omni V contract in 1999. However, this purchasing was eventually cancelled because of the abysmal endurance of these tubes. Without a film blocking the ions emitted from the photocathode, the tubes degraded too quickly.
Unfilmed technology took about 20 years to work out the service life issues. Some of this timeframe was due in part to multiple turnovers in ownership, from Litton to NG-EOS to L3. The first unfilmed tubes by L3 were available in 2010, but it wasn't until 2014 that unfilmed technology was truly reliable, and it took another four years after that before L3 was able to consistently make reliable unfilmed intensifiers that also had high performing specs. So when people say that unfilmed technology is new, it is VERY new. As of this writing in March 2022, it's only about 4-8 years old effectively.
How L3 is able to make tubes without an aluminum oxide film that doesn't have ion poisoning issues is anyones guess. A somewhat accepted theory (because of hinting from industry sources, as well as the accepted understanding of how night vision works) is that L3 is in fact using a film, it's just of a different material. However, anyone who tells you they know besides an L3 Engineer is making an educated guess.
Thin Filmed Tubes
By the time the Omni VII contract rolled around in 2006, ITT had developed a thin-filmed tube that didn't have the reliability issues but did have enhanced performance. As such, ITT was awarded the bulk of that contract, with L3 being awarded the rest for their standard filmed systems.
Thin filmed tubes are still the most common tube produced today. With only L3 being able to product unfilmed technology due to patents, and the majority of United Stated military contracts not specifying for filmed vs unfilmed night vision tubes, thin-filmed intensifiers are produced in huge quantity by both Elbit and L3, in both Green and White Phosphor.
Filmed vs Unfilmed Night Vision: Performance
Ok, great. So we know the history of the tubes, and how we got to this point. Does anyone really care? After all, aren't you just here trying to decide what to buy, justifying your purchase, or just learn about the performance differences? Of course you are. So we're going to start off with what you really want to read, Unfilmed Tubes. Also, because they're being produced in such few numbers, and no commercial vendor really sells them anymore, we're dropping thick-filmed tubes from here on out.
Unfilmed Night Vision Performance
We could just tell you that the average unfilmed image intensifier is going to have better specs, but that's not interesting without understanding why. It's important to realize that the aluminum-oxide ion barrier film doesn't just block harmful ions, but it will also block electrons occasionally as well.
So, by nature of the Unfilmed system, when producing intensifier tubes, you're likely to come out with a finished product that has a higher Signal-to-Noise Ratio (SNR) than a system with film on it, blocking some of that signal. However, it's important to note that night vision production is not an exact science, and all tubes are essentially snowflakes, they are all unique in their final performance numbers. You can absolutely (and commonly) have thin-filmed tubes with the same SNR numbers (or better, there are low-specced unfilmed tubes too). The lack of film also helps reduce Halo numbers, as the absence of film in from of the MCP helps prevent electron scattering.
Ok, so what is the end user really getting, comparing a thin filmed vs unfilmed tube with the same specs? That's the real question, and the honest answer is... not a ton. The main advantage of unfilmed tubes is that you have higher specs on average, and a higher maximum spec ceiling. So with two tubes of identical performance metrics, the unfilmed tube will really only win out in much lower light scenarios. In extreme low light (think: no moon, overcast night, in the woods), the image that an unfilmed tube will put out will be a bit brighter and a bit more usable. In those situations, you're essentially getting a bit more gain out of your tube. In practical usage, we equate this to about a 10-15% advantage. It's not life changing, but it is noticeable.
So the main advantage of unfilmed night vision tubes is the ability to find higher specs on a unit you're looking to purchase. If you know you're dealing with commonly very low light scenarios, being able to buy a tube with a 37 SNR is going to be very advantageous.
Thin Filmed Night Vision Performance
As we mentioned in the previous section, thin filmed tubes of similar specs will have similar performance to unfilmed tubes, in all but the lowest of light. In fact, depending on where you live, you may never notice a difference at all.
Keep in mind, the Department of Defense purchases at least 10x more thin-filmed tubes compared to unfilmed tubes (they purchase roughly 10x more Elbit vs L3, and some of those L3 tubes are thin-filmed also). So our warfighters at large are faring perfectly fine with thin-filmed tubes. In fact, in the most recent ENVG Contract, it's being fulfilled with both Elbit thin-filmed tubes, and L3 Filmless tubes, because the military doesn't value any major advantage to unfilmed as long as the required contract specs are being met.
Filmed vs Unfilmed Night Vision: Cost
Obviously, given the choice, everyone is going to prefer filmless technology. Higher possible specs, slightly better low light performance, what's not to love? Well, probably the cost.
Unfilmed technology is going to cost more, there's no way around it. When shopping for intensifier tubes, the price disparity becomes immediately obvious. Unfilmed tubes run you about an extra 50%, or roughly $1,000 more per tube, at the low end, and almost double at the high end. Is that worth it? Well, it's all up to you. For some people, it absolutely is. This may be because they don't have financial constraints (lucky them), or because that extra performance is crucial for their use case.
We love all of our night vision. And we've never really met anyone disappointed by their first night vision device. For the average civilian end-user, a thin filmed tube will serve their needs well. However, for those who have to have the best, whether because they require it, or just want it, filmless is the way to go.
Enjoy Our Night Vision Blog?
Hope you found something of value to yourself here! We write these to try and educate and share information that we had a hard time finding when we were new to NVGs. If you liked it, sign up for our newsletter to be notified of new articles or company news. Feel free to comment what you thought down below, and we always love when our articles get shared for others to read.
