RPNVG (Ruggedized Panning Night Vision Goggle)
RNVG-A (Articulating Ruggedized Night Vision Goggle)
PVS-14 Night Vision Monocular
Video Transcript
It's Scott from Nocturnality and I'm here in the T.REX Armory. Today we are going to talk about the addition of L3Harris white phosphor unfilmed image tubes as an evolution to the T.REX ARMS night vision device lineup. We're doing this primarily to improve redundancy of supply chain, keep night vision devices in stock more consistently. So in this video, what we're going to do is we're going to answer, preemptively answer some questions around that about how to select tubes, why you might consider one versus the other.
We're also going to give you some contextual background info on generation three image tubes kind of in general and what that structure means, which relates back to why we're doing this. And then finally at the end of the video, for those that are interested, we're actually going to delve a lot more deeply into methodologies around evaluating specific image tubes based on real world and realistic scenarios and tube test data. So to preemptively answer the question that we know we're going to get, why are we offering now both Elbit systems as well as L3Harris generation 3 image tubes across the entire device lineup?
The primary reason that that is something that we're wanting to do is for redundancy of supply. In the night vision world, there's a historical precedence for supply chain kind of fragility. And then in the context of today, where everything is kind of disrupted and just we're in this kind of continued state of supply chain challenges, we think that this is probably the right time to add a second tube option with the L3Harris image tubes. So we're going to unpack that a little bit today.
So to give an example of, again, why we're doing this, to take a third image tube type of Photonis, for example, today, Photonis tubes are extremely difficult to source in the US market. That's been an ongoing issue for a couple months. That's primarily based around conflicts around the world. And Photonis is standing in the world outside of the US night vision market. So tubes are popular in the US. Already now, they're very difficult to source and a lot of companies are having difficulties with supplying those products. So we want to try to anticipate these issues because in the night vision world, governments tend to drive everything. And so when governments need night vision equipment, the commercial side for night vision and the civilian market tends to get pushed by the wayside and there could be significant supply disruptions.
We've seen that going back to 2020 and as well as much earlier than that in the night vision world. So redundancy of supply is kind of the main driving factor in the addition of a second image tube type with L3Harris. So what we want to do is kind of look at this from the lens of how the DOD and governments who are behind all night vision development, historically speaking, how do they view this and what can we kind of draw from that? So both of these, it goes without saying probably at this point, are generation three image tubes. And the generational structure for image tubes is something that came out of the DOD and our military's development of the technology. And essentially what that is, is a structure where any company in theory can create a product that aligns with that structure and then attempt to get it adopted by the government. And therefore there are multiple sources for what are in concert and in design kind of the same thing. There might be technical differences, which there are, and we'll talk about those a little bit. But the idea in terms of lifespan and just kind of equivalency and minimum specification levels and performance and things like that, those are all kind of predefined by the generational structure. So there's comments that could be made about whether that's relevant today or not. We've talked about that in other videos.
But just for the sake of looking at comparing Elbit and L3Harris image tubes, both being a true Gen 3 offering adopted by the US government, there's definitely a level of equivalent see that's already built in there. So we think that the best way to look at it is, L3 tubes, they cost more. There are some small performance benefits that go along with the unfilmed L3 technology compared to Elbit kind of in a statistical sense, not necessarily a every tube versus every tube on either option sense. So what we want to kind of call out with this new offering is that L3Harris tubes will cost a little bit more. However, you do get some performance benefits like an improved halo performance just across the board, as well as what we're going to be offering through T.REX ARMS is a higher minimum FOM guarantee the L3Harris offering.
So what that really boils down to is we don't necessarily want to encourage lots paralysis by analysis and comparing 15 different image tubes and trying to pick which is the best based on numbers and things like that that don't necessarily always really translate into meaningful performance differences in the field. So our recommendation is, and going back to redundancy of supply, based on the time when you're ready to purchase night vision, just choose the option which is more appropriate for your budget and taking into account availability at the time that you're ready to purchase.
You might be thinking at this point, doesn't this add more complexity to an offering that we kind of already took the stance of, you know, we want to sort of remove complexity from the existing kind of industry structure. Not really. And the reason why is because if you recall what we just talked about with generation three structure, the way to think about this is essentially that these offerings, while there are some technical differences in the actual image tubes themselves and the technology within each, they are viewed as equivalent offerings, even when there might be, you know, they fall within a range of performance where one two might differ from the other.
In the night vision world, the problem has never necessarily been that there's more than one image tube to choose from, and that's creating all kinds of, you know, headaches and paralysis by analysis. The main issue that we've seen in the last couple of years really is around choices that might have unknowns associated with them with regards to maybe product life, quality, support, things like that. And when you look at two image tube offerings specifically within a generation three structure, all that, you know, kind of potential pitfalls and all the research that, you know, you might feel like you need to do, that's already really been done.
We already have the generational structure for these two tube offerings. We know the lifespan. We know the performance capabilities. The supply chain has been established. And now we're just kind of moving to a little bit more robust offering for the sake of keeping more night vision in stock that is essentially equivalent. So that pretty much sums up the why, why we're doing this. It's all based around redundancy of supply, keeping more stuff in stock, more consistent flow of products. So now what we're gonna do, because this kind of brings up into the conversation a little bit more about comparing and evaluating image tubes, we're gonna delve a lot deeper into methodologies about how you might wanna go about doing that if that's something that you wanna do.
So I'm going to outline the steps of how you perform an evaluation. So I mentioned signal to noise ratio is the most important. That's where you start. A tube's signal to noise ratio. So when you look at your tube's tested data sheet, there's a metric on there called the signal to noise ratio. It's an individual number. So that's where we start. We multiply the signal to noise ratio by a factor to elevate its importance in the equation because signal to noise ratio is the most important single spec in terms of image performance. So what you're going to do basically is start by subtracting 30, the number 30 from your tube's tested signal to noise ratio and then divide that result by 10. Add that result to a baseline multiple of 4.0 to get the actual multiple that you're going to use.
Then multiply the tested SNR value from your data sheet by that multiple to get what I call the positive performance value. The range for this should be somewhere in the neighborhood of 85 to 140. From there, we account for negative factors that degrade an image tube's performance and ability to recreate an image. And those are taken into account primarily the HALO and the EBI. So again, back to the tube's data sheet for those values. Because we believe HALO is kind of the most significant detractor from an image tube's quality and image recreation performance, we also multiply the HALO value from your data sheet by a multiple. And that multiple is always going to be 3.0. So you multiply your HALO by 3 and then you add your EBI from the data sheet, maybe it's 1.0, to that value, the HALO times 3 plus EBI. That is your negative performance value. A common range for a negative performance value might be something like 2.4, maybe ranging up to 4.4. So at this point we have a positive performance value, we have a negative performance value.
You divide to finish the evaluation, or to get to the next step of the evaluation, you divide the positive performance value by the negative performance value to get a balanced performance value. And then you subtract the original signal-to-noise ratio from your data sheet from that result. What have we done so far through all those steps? We've essentially elevated the metrics that greatly impact a tube's ability to recreate an image, its performance, factored in the minor impacts, negative impacts of HALO and EBI, by subtracting, and then we've subtracted the original SNR from this. So what that does essentially is, if that result is above zero, we've shown that a tube's signal-to-noise ratio is overcoming its negative aspects, or maybe it's not at that point. We've also purposely excluded the center resolution value from the equation entirely, because again, I mentioned earlier, this is for ground-based systems.
Ground-based systems aren't super-sensitive to a tube's center resolution, because the minimum values at this point in Gen 3's development are already typically above our ability to detect any meaningful difference without the presence of magnification. So our human eyes generally cannot tell the difference in any meaningful way between a 64-center resolution versus up to an 81 or higher. So we've excluded the resolution. Now, that's the opposite of what Figure of Merit does, so I want to call. And now, it's time to factor in things that impact a tube's usability by subtracting or adding points back, based on once you are able to power the tube up, see any spots or any weird light behaviors, and I'll go through those. So with that score that we had before, after dividing the positive factor by the negative factor and then subtracting the original SNR back from that, you have.
That's kind of like your score, but we're going to change that score a little bit based on some of these other factors with cosmetics and image tube characteristics when it's actually in operation. So you can actually add different things to this if you want. What we have done is some basically plus or minus points to that original score, based on some of these things. So we subtract a minus one for something like a zone two blemish of the smallest size category, which is three thousandths to six thousandths of an inch. Image tubes, data sheets will have typically a spot chart, both for Elbit Systems and L3Harris now. They'll have a spot chart which records these, shows any image blemishes in a tube of a certain size. So we subtract a one for a zone two blemish of that smallest size category, or we would subtract two points for any zone two blemish larger than the six thousandths of an inch.
We also would subtract two points for a zone one blemish larger than three thousandths of an inch, although you probably won't see that in most Gen 3 image tubes. We also would subtract two points for noticeable or excessive micro channel plate over-saturation or phosphor persistence. That's something you can only see if you power up an image tube and maybe around light sources you see streaking effects or some kind of light trails as you kind of pan an image past light sources. Some image tubes have those characteristics and while they're not a huge deal, they do kind of detract from the usability and the value, so we definitely want to take those into account as well.
So you would subtract points for cosmetic and usability factors that I just mentioned. You could also, we add points for tubes that have no spots, larger, recorded on the data sheet, larger than three thousandths of an inch, so essentially a clean spot chart. We would add two points for that and we also add two points in the uncommon example of tubes that have a highlight resolution value greater than 36 line pairs per millimeter. Usually you'll only find that tested on an L3 tube data sheet, but it is an important characteristic in terms of usability because the highlight resolution of a tube actually gets into levels where our eyes can tell a difference between different values. So 36 is kind of the standard, almost all tubes are 36 line pair per millimeter highlight resolution, but some are a little higher than that. So if it is a tube that has that, we add two points back for that.
So let's roll through one of these calculations live to give you a little bit better idea of how to do this so I've got a tubes datasheet pulled up here that I'm going to reference and I'll talk through as well as a Calculator right here that you're going to need so that first step is to subtract the number 30 from your tested Signal noise ratio on your datasheet in this case. It's 30.5 So we're going to take 30.5 minus 30 and then you divide that by 10 and add 4 So that's your multiple that you then multiply the tested signal to noise ratio by for your positive performance factor So it's 4.05. We're going to multiply that again by the tested SNR which was 30.5 So Our positive performance factor on this specific Elbit systems tube that we're looking at right here is 123.
You can go ahead and take away any decimals at this point We're just going to go with 123 flat now we have to divide that by the negative performance factor Which if you recall is the halo value tested halo value from the datasheet We're just going to go to one decimal place because that's you know It's not all these values are not necessarily tested to the same level of detail in terms of You know decimal places, so we're just going to go with one decimal place So your halo which is 0.8 on this specific tube you're going to multiply that by this this is always multiplied by 3 and Then you add to that your EBI which in this case is 1.1 and that is your negative performance factor So that ends up being 3.5 in this the case of this tube now you divide the positive performance factor Which was 123 by the negative performance factor, which was 3.5 All right That result is 35.1 The last step to get your final kind of overall score before we factor in usability things is to subtract The original tested SNR which was 30.5.
So at that point your balanced performance score is 4.6 Now we have to take into account things like tube cosmetics And I haven't been able to power this specific tube up So I won't do that you know and take into account that specifically but right now before we take into account any tube cosmetic things. This tube is scoring a 4.6 on the pVu scale so if we reference the tubes spot chart right here it does have a zone to blemish of 3000 to 6000 size range so that if you recall earlier in the video is going to subtract one point from the score and The final pVu score of this specific image tube from Elbit systems is a 3.6. So that is just outside that negative three to positive three range of kind of like that passing score It's a little bit higher than that probably not significantly enough But that is a an acceptable tube and something that we would say is capable of performing in general any ground use task and therefore would be a candidate for purchase in a civilian context.
Okay, so that is the PVU method that we developed for evaluating image tubes. Let's talk a little bit about some takeaways from that. Again, the main takeaway I would say from this is that the vast majority of current and even recent production Generation 3 image tubes are, in our opinion, more than suitable for kind of general purpose night vision use in a civilian context, especially in a ground system.
It takes a lot of kind of complex negative factors that are pretty uncommon for a tube to really be considered not worth owning, not worth purchasing, and really just noticeably not as good as most of its Gen 3 kind of counterparts. That's one of the biggest takeaways from this. And because, you know, in the night vision world, you certainly should learn about image tube specs and performance and what all these words and numbers mean. But what you'll find by using this method is that you can do all of the research and you can do all the calculations and things most of the time just to kind of find out that, yeah, most of the tubes out there are actually going to work just fine for what you need to do with them.
And so we kind of want to present this message of reassurance that the generational architecture of tubes, it might not be super relevant necessarily today for certain things, but it does definitely give the consumer of night vision kind of unintentionally some reassurance that what they're going to spend their money on is actually going to perform, not only perform the task that they need, but it's also going to be a good value. Despite, you know, small differences in numbers on data sheets and things like that. So also another takeaway is that we need to look at, if you're truly evaluating an image tube, you need to look at the relevant performance metrics from it and not just a mishmash of numbers that, you know, don't necessarily mean anything in the context of, say, putting night vision on your head and going out and training or something like that.
So we need to look at the important metrics and we also need to take a more holistic view of an overall usability of a tube with taking into account, you know, maybe different characteristics it might exhibit in the field when you're actually using it. And then also value as well, because a lot of people are really concerned, rightfully so, about value. So taking into account things like the cosmetic properties of tubes in concert with all of these things to kind of do a full evaluation for an image tube. So to manufacture standards, especially in generation three and even competitive technologies like Photonis, they already should provide some solid peace of mind for the night vision buyer. But just, you know, for your own purposes, if you want to take and use this method on an image tube that you're considering or maybe that you've already owned and just see how it stacks up. This is a smarter and probably more useful way to do that.
If you have questions about image tube offerings, tube specs, anything like that, night vision devices, you can always contact us at team@trex-arms.com. You can also contact us at Nocturnality directly. Follow us on Instagram. And we'll be happy to help.