I currently have the NGI Gen 2+ PVS-14. It works great and from what I can tell, the specs on it are pretty close to Omni III. Would a Gen 3 Omni IV be a huge improvement or would I be better off keeping what I have and saving up for a Omni  VII or VIII? Yes, I know those are amazing.

I have no experience with gen 2 unit’s of any kind personally but my old Omni IV tube was quite impressive even compared to my newer VIII thin film.

Omni IV tubes are great and are probably the best bang for the buck performance wise. The difference with Omni VII requires side by side comparison and that's if the Omni IV tube is at the minimum of its specs.

One of my go-to monoculars has an Omni IV tube and it keeps up with another unit that has a filmless tube. Unless it's pitch black, the difference just isn't there.

No, you couldn’t see a difference...(probably).  The thing that might be better is the sensitivity.  That’s what I usually see as the difference between Gen 2 and 3.  I will echo the Omni IV opinion...nice tubes.  I’m a little dubious on seeing difference in one contract generation...

Omni IV should be slightly above the baseline spec of NGI Gen2+... And I suspect would have better performance.

But I doubt you'd be able to tell the difference under most conditions, and without knowing exactly what specs you ended up with, there might be no advantage. Also consider that you're comparing a NEW Gen2+ to an AGED specification Omni IV, so there might not be any advantage at all in changing if you're just getting a secondhand tube.

So the NGI-Gen2+ are probably better value than some secondhand Gen3's which they'd compete directly with on price alone even if it weren't the case.

Still, if you managed to get a new Omni IV spec tube, it would still be an improvement.

But, if you want something a little better, I'd suggest saving for a nice SNR30+ system :) That won't necessarily be all that noticeably better than the Gen2 or even Omni IV under most conditions, but when it gets really dark, you'll definitely appreciate it.

David

I shall direct you to this post with all the pics.

Check this post for Omni differences.
https://www.ar15.com/forums/armory/-/18-435456/?page=1

 When did you purchase your NGI pvs-14 gen 2+? Did you happen to get one with a spec sheet?

I missed the boat on those. Going by the website numbers.

I have a couple of Omni iv tubes in a dual mum setup. I think they’re great for the price. I had an Omni vii before these tubes and sold it to fund the two Omni iv’s. My eye couldn’t tell a real difference between image quality. If you put them side by side you could probably see a difference but the iv’s are great bang for the buck.

It is a shame that this wasn't stickied. I remember reading this back then and thinking it was quite a resource.

Agreed!

OMNI IV tubes are some of the toughest tubes out there while also being very good to high performance. Most OMNI IV tubes had halo values that were near or greater than the max allowable halo value for the tube because the halo value is a pretty relaxed perameter as halo size is only really a preference to aviators who lile small halos and really only matters and is important for weapon mounted application where a high halo value is paramount.  the larger the halo value the more resistant to recoil the tube will be. Adding to the recoil resistance is the fact that they use DC nongated piwer supplies. Autogated PSU's  can add to the risk of recoil damage. They cause the electrostatic field between the PC amd MCP to change constantly because of the autogating feature turning the tube on and off continuously at a very rapid rate. The change in the electrostatic field attract and repel the MCP at its center continuoulsy. So the center of the MCP os constantly moving forwards and rearwards, getting closer then farther away from the photocathode.  so if used on a rifle and the recoil force that is travelling rearwards coincides with the forward flexion of the center of the MCP it can cause it to flex even further forward and strike the PC and leave a very bad burn. if tube is filmed it will smear the film all around the burn mark making the damage even worse. A DC PSU does not experience the change in the electrostatic field between the PC and MCP like an autogated tube does and the filed remains constant and doesnt change at all. So the MCP in a DC tube is not flexing forward and rearward constantly like it would be in a tube using an AG PSU. BtW, the humming that is heard eminating from autogated tubes when powered on is actually the sound made by the MCP flexing at its center forward and backward at a very rapid, constant rate. and ive seen alot of omni IV tubes that performed leaps and bounds above some omni VII and VIII tubes I have had. Every OMNI era saw production of contract tubes that perform at super high levels well over the minimums and then tubes that perform below even the minimum requirements due to the way the tubes are tested to see if they passed milspec and or meet the contract minimumso be sold under a specific contract. My advice is if you get a chance to pick up an OMNI IV tube at a decent price, dont hesitate to buy it. most of them are good performers.

Also I would say that any Gen 3 OMNI IV tubes will handily out perform any Russian made gen 2+ any day. Especially if the 2+ doesnt come with a spec sheet included with the tube. No spec sheet usually means the tube is a low spec tube or there is some issue with the tube and it was sourced for much cheaper than usual. No tube manufacturer would bother testing a tube to create a data sheet if it was not worth their time to do so because the value of the tube has been degraded too much due to some problem or issue the tube is experiencing. Or it is super low performing. They will be sold without data sheets cheaply in larger wholesale lots. NO brand new ITT/Exelis/Harris tubes, brand new Litton/NGeos/L-3 tube adn no brand new Photonis tubes that pass milspec or comm spec will be sold without a spec sheet. Even the spot spec tubes from all three manufacturers come with data sheets.  so yes id give the performance edge to any OMNI IV tube over any generation 2+ that isnt supplied a data sheet upon purchase.

So would you say that NGI's gen 2+ pvs-14 is likely a low performing cheap system? My did not come with a data sheet, and NGI refuses to disclose the exact manufacturer's they get their tubes from, however it performs quite well against my gen 3 pvs-14 that has a SNR of 29.9.

Omni IV is near indistinguishable from Omni VII (and better). Really the benchmark for what NV should look like. There are Gen 2 tubes that match (and can exceed) Gen 3 performance and they cost about as much as (if not more than) great Gen 3 tubes, for good reason.

Looks like the NGI PVS-14 has a SNR of 16-18. With the inherently lower photoresponse of Gen 2 photocathodes, the tube is going to struggle some when it gets dark (no moon). SNR and resolution may be almost identical to Omni III, but the photoresponse is in the 200-400uA/lm range while the minimum for Omni III 1350uA/lm. That big a difference will let you know it's there.

The 16-18 SNR and 51lp/mm resolution screams Russian tubes. 51lp/mm is the norm for a certain grade of tubes that Katod sells. Some of the -14s from NGI do use Russian tubes (obvious upon opening them up). Very well could be exceptions.

How would I know upon opening the unit? I purchased the "Plus" model April of 2016 which from what was explained to me,  that it may NOT have Photonis markings  but would have been made in the same facility so I don't know. Also I looked into Kotad and found a website. All of their Gen2+ states 10,000 MTTF and NGI states 5000 for their units, so that leads to more confusion. I've asked NGI/TNVC on a few occasions what may possibly be in the NGI pvs-14, but they aren't willing to elaborate for whatever reason. The lack of transparency is a bit peculiar for a company that has such a stellar reputation.

You know how I know that you don't know...

A bit funny, but you should at least explain it to the guy.

txdx, the SNR is measured well below starlight level, and the human eye makes up a lot for amplification, so it's a pretty effective measure of performance right down to overcast starlight.

So two tubes with the same SNR measured in the same way ( PHOTONIS and US measurements are the same, Russian measurements vary ) will perform roughly at the same level regardless of technology.

Overall gain may change a little, but that's usually due to more than just PC response and the eye can usually cope with it just fine - and usually that's just a brightness issue. As long as the system gain exceeds 2000x, it's generally not a major factor.

To date, PC response has only proven useful as a spectrum measurement ( eg, QE across 200-1000nm ) and in determining whether a particular tube in a batch is better or worse than the others based on mapping that function against EBI. But it's not proven very useful at all in determining tube performance.

I wrote and presented a paper on it a couple of years ago, and worked out that the information could also be used to generate a co-efficient to allow direct comparison between Gen2 and Gen3 tubes, using the older ITT thin-film technology as a baseline and s/n as a common factor for equalization.

So unless you're using it as an alternate factor in some other calculation, Photocathode Response can be safely ignored in most tube decisions. There is a point where, along with QE, it does affect the ability to create an image, but the brain will lose the ability to form the image long before the tube loses the image.

Regards
David.

Haha, it has been a time or two that I've asked and as I've said it is only out of curiosity. Like, I would like to be able to head over to the Photonis website and know kinds what model the unit has. I never once said I was dissatisfied. On the contrary,  the tube is quite good and keeps up with gen 3 so well that THAT is what has me so interested in it. I know the newest and greatest white phosphor is what everyone is buzzing about, but idgaf about that at the moment. I just want to learn an much about the units I have. There wasn't any "bashing". In my mind when I'm asking what model number of tubes and I'm being told "they come from Europe from different places" that kinda doesn't really answer the question hence the repeated asking. For example,  one model of Photonis tube that I'm familiar with is XX1940GL. That's only a random example I used, but you get what Imean. Haha "Other companies" dont get asked anything because a lot of them put out shit products and when someone buys them and whatever low price, they don't question it and just accept it. For me though, the NGI is a great product and performance reflects that so I want to know about it! That's all! YOU'RE NOT GETTING IT BACK DAMNIT! IF there is some reason that you cannot tell me a particular model number then just tell me that, and I'll let it go. Just a direct answer to my direct question.

On a related note, any idea how exagerated the russian snr numbers are? Ive got an armasight unit with a WP gen2 tube that i suspect is russian.

Do appreciate the input. Agree that PC response isn't worth worrying about when looking at the typical spread among good Gen 3 tubes. Wouldn't worry about two tubes with a PC response of say 1800uA/lm and 2400uA/lm. SNR and EBI would drive my preference there, with a stronger emphasis on EBI than most due to astronomy usage. The usual though not overly firm correlation that I see between high PC response and higher EBI alone would make me shy away from higher PC response in general. This, of course, assumes that the tubes in question are both filmless or filmed, no mix and matching.

That being said, a factor of two or greater difference in PC response is detectable by eye. With side by side comparison and dark (really dark) conditions, I'm decently confident that I can detect it by eye without relying on imagination. I may have exaggerated the apparent difference somewhat and I may be looking at the tubes more keenly than I should but it's there. Comparing a good Gen 2 tube (400uA/lm response assumed, for the sake of discussion) and a good Omni 4 tube, the difference is there and it's not entirely due to the potentially somewhat lower SNR of the Gen 2 tube. The Omni 4 tube is getting twice as many photoelectrons hitting the MCP (after a good chunk are eaten up in the film). Similar visual difference between an Omni 7 tube and a filmless tube with a PC response around 2400uA/lm. Is it all imagination?

Don't think I saw the paper you mentioned. Definitely would like to have a look through it and save a copy.

Either they are or they are not. I've seen Russian Gen2+ tubes that were probably around SNR 10 to 14 with claimed SNR 56+ - If the figures seem real, they probably are - If they seem fanciful, they probably are.

David

I used to think it might happen under really dark conditions, and there's a transition point where the human brain can no longer assemble the image information into something meaningful, but a long exposure photograph shows that the image is present and clear.

Originally I was testing a XR5 tube against Omni IV and it failed to produce an image before the Omni VI and was about equal to Omni IV, but INTENS can beat out the Omni VI and I've heard they can beat out even Omni VIII's but can't take on a high SNR filmless equally yet.

Now what you're saying is still pretty valid, but clearly the lower PC response tube is killing the higher PC response tube if that's the case... No way even an INTENS can come close to a mid-range Gen3 PCR right? The reason is the spectral spread.

PC response is measured at a single frequency and doesn't represent the real light at night. It's based on a single 2856K measurement, but doesn't take into account skyglow at all.

From XR5, Gen3 loses at the top end of the spectrum. INTENS absolutely kills it though - After 850nm, a 4G tube typically outperforms an Omni VIII Thin Film tube and most likely even a filmless since this is related to material properties of the Gallium Arsenide photocathode.

As a result, based on the 2856K test alone, the PC of both Gen3 and INTENS outperforms a tube that only follows the 2856K curve, but the newer Gen2 continue further up above 900nm than Gen3.

So there's actually more photons at night, not less.

2856K is  based on the idea that we get all of our light from sources like the sun. But most of the light at night comes from Starglow - It can be up to 10 times or more than 2856K light would account for - And is so strong in the SWIR region that even cameras can see like intensifiers at night.

This means the standard under which we measure tubes it outdated and fails to address recent technology changes at all. If you're comparing Gen3 to Gen3, then it's fine, because even if the curves differ from 2856K, they are similar - even between manufacturers and technology improvements. But SuperS25 doesn't follow this curve.

David

A) Why are you pairing two people together?

B) What exactly is my motive, Vic?

C) I’ve never said anything about NGI tubes.........Like ever.

I'm fairly certain he doesn't mean you

What I was actually getting at was also the fact that ion barrier films eat a great deal of electrons (50% or more on earlier G3 tubes). So looking just at PC numbers is useless, since its only the elecrons that make it to the MCP that matter. Then how the MCP is biased also makes a big difference gain wise. If you compare an Omni2 tube with a PCR of 1000, you are likely only seeing 400-500 uA at the MCP. Compare that to a gen2 tube with no film and wowzers yoh cant see a difference even though the PCR is 2x for the G3 tube.

I'm quite happy with mine. It's a great unit.

True, There's the film in some tubes, and there's also the closed area of the MCP to consider as well, and that's before we even consider comparative MCP gain and screen focus and other mechanical aspects that affect how PC response pans out too.

Yup... all good reasons why PCR compared between different units doesnt really mean much.

I understand I keep bringing this up, but I feel as thought this is worth mentioning. I called Armasight today to inquire about the gen 2hd pvs14 that I have from them. I asked them if they could tell me what manufacturer the tube was from and possibly a model number. A half an hour later I received an email with the manufacturer and model number.  It is an Ekran FEP tube model IIT2GDX. The fact that it's Russian means nothing to me because it is a fantastic performer. The point is, they were willing to give me that info and for that I am greatly appreciative. I'm not saying that TNVC/NGI customers service is bad, but that maybe others aren't necessarily bad either and that all I was looking for was a little info on my investment. I'm not asking or expecting anything of NGI that I don't also from other companies who's products I've purchased.

You say you're not saying TNVC/NGI's customer service is bad, but let's be clear on this. You don't appear to be doing the kinds of things that would reasonably be expected to achieve your stated goal, such as contacting them quietly, out of channel, and asking them directly and personally. And while that might not work, it's still generally considered a polite way to do things.

No, Instead you're publicly ridiculing and cajoling them in an attempt to force them to acquiesce to provide services outside of the conditions of sale you're well aware were clearly stated at the time of purchase, and the conditions of sale were both morally and commercially sound and above board.

You're also reasonably likely to be aware of the reasons why retails sometimes don't provide this information, especially if they are higher quality lower-cost devices. For example, if a tube manufacturer wants to move excess stock, and they heavily discount a high-end tube and sell it as generic, you don't seriously think they want the world to know that their flagship tubes are being sold at giveaway prices do you? There are a LOT of valid reasons why a company may not be able to reveal this kind of information, and regardless the consumer benefits. There could be any number of reasons a cleanskin tube is sold at a lower price than it's milspec equivalent.

And I'm guessing you don't ask these questions publicly in this way of a lot of other companies, despite your protest otherwise.

You're also actually pretty au fait with the technology.

In which case you probably know you can get someone to provide the testing services to reproduce a datasheet for your tube, for a reasonable price, and you don't need to badger the OEM for this information.

So, paying for a service that you're not entitled to receive for free is not really an unreasonable way to get what you want is it? Last I heard, it was only a couple of hundred dollars to get a datasheet reverse engineered.

David.

I publicly apologize to TNVC/NGI. As far as contacting them directly,  you're right. I haven't.  I had no choice with the other companies, as they have zero presence on this forum. That in of itself speaks volumes about TNVC/NGI customer service and they're typically quick to respond here. I'm not one to take sides with or against a company as I have little experience outside of the military with night vision. My approach was lacking in professionalism and out of line. I have made TNVC/NGI aware that I AM very satisfied with my unit. Always have been and I suppose I have given little thought as to the reasons why they may not want to put that info out in the public eye. I also apologize to the OP as well for being this nonsense to their thread. I will no longer ask about it. I don't spend a lot of time on this forum or any other for that matter as I have little personal time available to me, so I suppose my forum etiquette sucks as well.

I actually took some video tonight through Omni iv tubes to try and demonstrate their goodness I also had my solarforce ir dropin led on display. It’s not the greatest video but hopefully it can give you a good sense of budget friendly (if there is such a thing WRT NV) performance.

Anyone know the best way to host/upload videos?

You heard of youtube? (edit: people seem to use mega.nz for videos / general temporary hosting)

Ha! Heard of them a time or two..

https://youtu.be/Gxok0VjH18E

Edited: made the link hot