Just a quick comparison of a Gen 3 Omni VII vs a Gen 2+ tube for anyone wondering if the extra 1000-1500 is worth it. Both tubes has manual gain and are autogated. The pic is done at the same distance, same housing/lenses, with a LIF filter on the front lens, under the same lighting conditions approximately 30 minutes from each other. There is a bit of light pollution since the pic is done 10 miles from a major city so even though it's a lightly wooded area it's not as dark as it could be to take advantage of the full capability of the Omni VII, but is a great example of a typical urban environment scenario. The distance to the tree line is @ 75 yards away and the gain on each is adjusted to pick up the maximum clarity through the tube. Just a note the Omni VII had quite a bit more gain to almost seem light bright day light is flooding the back ground. Just a note that the image through the PVS14 is much clearer than what the cell phone camera can pick up. The detail of the Gen 3 is much clearer/cleaner. In a no moon/star/light pollution/under a heavy canopy the Omni VII will hands down beat the Gen 2+ tube, but with additional IR light the Gen 2+ preforms quite well.
First up Gen 2+

Omni VII

Second pic no bueno.

Where is this Gen2+ from?

Night Ops Tactical http://www.nightopstactical.com/PVS_14_Night_Vision_Monocular_p/00172nt.htm

I actually like the tint on the 2+ better.

Can you shoot some pics of a more urban environment?

PS: Thanks for sharing these with us.

The tint in the pic does it no justice and not even close on how clear it actually is. I'm with you that in an urban setting the Gen 2+ does have a nicer tint to it.

SOT I actually dropped in the Omni VII tube in to upgrade my NODs and probably going to list it in the EE to recoup some money so the wife doesn't kill me. But then again if I can find a complete kit for a killer price, then I'd keep it for a loaner and happily spend a couple of months on the couch.

The more ambient light the more similar the images will look.  The biggest differences will be line pairs.  Gen 2 tops out around 45 but gen 3 can be up around 64-72 so you get more detail from the same image.  I have both and the gen 3 starts to shine with no moon or 1/2 overcast sky.

The latest Gen2 tubes will easily outperform Omni VII - It really depends on the tube spec more than any other factors. It's not really a case of saying "Gen2 vs Gen3" anymore - they both occupy the same range of performance, use the same phosphors and have similar gain. At the very top it's no longer certain which is the better performed, and both Gen3 and Gen2 have weaknesses that the other can exploit. Gen3 can't see Out Of Band, while Gen2 requires a better lens system to gain the full potential. 





This is how two closely matched tubes ( S/N Around 28, FOM around 1800 ) perform. All specs except EBI are very close.  Urban environment during a wide-area blackout, 20km from city center. 

4G is Gen2. 

It is always important to know the specs of the tubes being compared - Otherwise a full comparison is very difficult. 

Regards
David

LOFL... They were making gen2 tubes like that in the mid 80's, today Gen2 tubes can easily be 72 lp/mm or better. Like CJ said, you really have to look at the specs to be able to compare. And realistically even in the 90's up to date gen2 wasn't really that far behind Gen3 of the day. Its just that most people were comparing apples to oranges comparing late 90's era Omni IV tubes to ancient 70's era MX9916's.

Wow that's completely indistinguishable.

From all I have read and understand, if the US had keep developing gen 2 as the Europeans have they would have found that gen 2 can be very comparable with gen 3 with one exceptions. Theory says that gen 3 will have and advantage in S/N when all is said and done with development. While other things may have small differences they will have little effect in the night vision world. And example of this is the MCP does not have to generate as much gain in gen 3 as in gen 2. The reason that the signal to noise in gen 3 is better is that the photocathode is in theory and practice more efficient at converting light into electrons and can do it over a wider range of frequencies useful in night vision. All other specs. can be built into either tube, state of the art permitting.  

What this means is gen 3 will always have and advantage in very low light levels.

Note, the above comparison dose not take into account cost or tube life.  

David please go lightly on me.

Do the common glass used say in PVS-14's actually restrict passive use to a degree that is noticeable? Can the INTENS tubes see enough of skyglow to affect performance negatively with current glass - meaning does it smear the image, being very out of focus, or something like that?

I'd say your analysis is spot on, until you start talking about Intens... I haven't seen anything about either the PC chemistry or a QE/wavelenth chart for it though. So I'm not really sure I'd call it Gen2 unless the PC is some magical multi-alkalai but it might be...

Realistically PC gain, is the integral of the QE/wavelength and the visible light spectrum. Moonlight (Which is just reflected sunlight) dominates the entire night spectrum when it is present, and its very well matched to Gen2 PC's, while the near IR spectrum from starlight dominates when there is no moon and is better matched to Gen3 PC's. So both tubes tubes do great when there is any moonlight, but gen3 does better when there isn't.

Historically Gen3 PC's had much better QE (~50% vs ~25%) than Gen2 PC's but gen3 also was required to have the ion barrier film which ate 50% or more of the electrons, so when comparing specs you can ballpark it by dividing the Gen3 PCR by ~2.x to get a rough idea of electrons actually getting to the MCP. Thin films reduced this penalty to ~30% and then filmless obviously eliminated it.

INTENS is multialkali - It's a classic Gen2. It's just that PHOTONIS continued development until they got to where they are - If you follow their line, it's not something that happened overnight. They've been improving technology almost in lock-step with Gen3 development and until a few years ago, were just a little behind. I think that gap has closed a lot of late. 

Meanwhile, the US had no incentive to keep developing Gen2, as the decision to move to Gen3 was made by the .gov - this was rather shortsighted in the long run, but the US has dominated night vision for over 40 years, so it wasn't a bad one either, well at least not until recently. 

Anyway, the concept that starlight dominated night vision was a view held by researchers for a long time, but it's not correct. Sky glow dominates the night sky spectrum, and by quite a bit. There's not much under 900nm, but even with what little sensitivity Gen3 has above 900nm, it helps it significantly - Gen3 lenses are good well up over 1000nm, even if they are somewhat chromatically limited. 

More recent studies have identified a lot of skyglow between 900nm and 1050nm - this gives INTENS quite a boost. 

Anyway, this is what the typical low-light night sky looks like, at a dark skies location, including skyglow.




The cyan line is the one that is close to those used for previous NV research. It assumes a lot of sunlight type spectrum. The blue line is the approximation of 2856K - which is used to test NV. As you can see, it's a pretty good fit for the older model.

The red line is a more realistic view of the night sky spectrum. If you don't go much over 900nm, and certainly no further than 950nm, it's not too bad. But once you factor in 950 to 1100nm, things get very different very quickly.

Put another way, the 2856K standard had some relevance until recently. Now it's pretty much useless as a true baseline standard. 

David. 

Any details on the intens PC chemistry?

Also spectrum wise i was thinking this instead of the dark sky specrtum you posted. If the moon is out its mostly irrelevant.

With so much more light available above 950nm, why is the Intens tube not kicking the GEN 3's ass?

What are the driving forces of what you call "skyglow"? Is this reflected terrestrial light, sunlight that is reflecting off of the atmosphere and wrapping around the planet, or something from entirely outside the solar system?

QE is probably lower.

The former as i understand it.

I don't know specifically why INTENS is so different. If I had to guess though, I'd probably assume something significant with respect to band bending coupled with a more effective mix of multialkali. 

As for "Why is it not kicking Gen3's ass?" - I guess you could also ask the counter "Why is Gen3 not kicking INTENS' ass?"

And the answer is pretty much that these two different technologies are actually very similar in performance, while having very different characteristics. 

The fundamental difference between Gen3 and INTENS is that Gen3 gets all of it's illumination in a small, narrow band, from about 550nm to 950nm, while INTENS takes it's illumination from a very broad spectrum which would be roughly equivalent to 300nm to 1100nm. 

In some cases, this can and would lead to asymmetric warfare if the opfor had INTENS, since it can leverage out-of-band quite effectively. This is why the US is suddenly pushing hard for out-of-band development in the lower SWIR region with it's existing manufacturers, but the technology of choice at the moment appears to be EBAPS, which can't counter INTENS either. 

Much of the US research into OOB, as I see it, appears to have missed the significance of fully leveraging out-of-band. It would be correct to say INTENS has leapfrogged US capabilities and the US is behind in this area for the first time - perhaps this is only mitigated by the fact that getting the full benefit out of the INTENS tubes isn't possible at the moment. The technology not only leapfrogged intensifier technology - optics technology hasn't caught up yet either.

Also, INTENS is an umbrella term with as wide a range of performance as, well, almost as wide as "Gen3". And not every Gen2 tube on the street has the same level of performance... 

What has happened is that a new technology has presented, it's suddenly in everyone's face, yet the full understanding of that technology has not yet emerged. In some ways, Gen3 still has the advantage. In other ways, INTENS clearly leads now. 

As I was saying a few years ago, it's going to get interesting - and there are only two heavyweights now. L3 and PHOTONIS. 

Harris has some cool stuff they could do too, but they are suffering from a serious lack of leadership at the moment, and from all signs of late, they don't have the right people at the top to pull themselves up by their bootstraps this time. 

Regards
David.

I didn't see a direct answer to this so I thought I'd bump it because multiband focusing has been a boogeyman for me on a couple of occasions.

Does anyone here have an idea on how to determine where a certain wavelength will focus compared to the other wavelengths? Is it linear or is it on a curve? It looks like the new lenses will be trying to get a wide spectrum of light to focus at a common point.

Current glass is pretty good in the lower SWIR regions out to around 1100nm, and so INTENS would benefit, though there's more that could be done there.

Also, most optics seem to either focus on 500-900nm or 700-1700nm. Neither is really a good fit.

Regards
David

Thanks, for taking the time to answer this, David. It does answer some questions for me.

will there not be difficulties focusing the light from such a wide band with the one lens - using a nv scope and say, skyglow then turn on the ir. illuminator and i have to re-focus quite a bit  because of the different frequency of the ir. light

Yep, that's pretty much correct.

Current apochromatic lens technology doesn't achieve the optimal solution. 

https://en.wikipedia.org/wiki/Apochromat

Well this is certainly an interesting thread.  Before some folks were talking about making a list to compare the specs of the available NV equipment out there.  Some said we've re-hashed all that before; it's all in the threads and stickies; go look it up.  Now I read in this thread that other countries have been pushing gen II tech out there to challenge gen III.  Seeing how the older threads and stickies pretty much just covered ITT/Harris, and (early) L3, would it not be fair to say that we would no longer be "reinventing the wheel" by making a new chart to compare the capabilities of "Photinis", or whoever these new vendors are, with L3?

You can't have it both ways.  At one point some guys argue that it's all been said and done.  Then at another, it is said that the emerging gen II tech challenges the gen III stuff.  So why wouldn't you want to incorporate the specs from this new stuff into an updated data base?  Just sayin'.

As a practical note, I find it interesting that other countries are trying hard to defeat US NV capabilities.  This is a concern, but then again it's not.  If you talk to all the tech guys, they think you can win a war with all this shit.  If you talk with the grunts, they will laugh at you.  I love NV but I am under no misconception that it is the all-seeing eye of Mordor.  You still have to know what you're doing.  

But anyways, fascinating thread.  Carry on.

Just like that thread a new one won't go anywhere.  People will disagree and that's on top of the high school drama that will go on between grown men who get their feelings hurt because someone else can contribute as much as them.

Until a fully recognized governing body forms and then agrees on what's what the only thing that'll occur is philosophical masturbation.

I would love to see a L3 WP vs INTENS with some filters, low and high pass on different wavelengths. I guess enough people here already own 4G or INTENS if they are labeled as such tubes that someone should do it

I have wondered about the comment in red. I have not worked enough with supplemental light to do any real isolation on this. Is this problem mitigated at all by using 940nm supplemental IR versus 850nm?

The reality is that its always been this way and thats why no one really cares to rehash it. Several european countries used to make gen3 gear and gave up on it. Its mainly a case of it not neccisarily being better but different. Intens and OOB stuff is interesting mainly on a tecnical and tactical level which isnt too relevant to the average guy, who just wants to see in the dark.

Well said Harlikwin,

Most of the technical side of NV has very little place in hunting pigs, or getting around the farm after-dark.

It does have some relevance for preppers, because many work on the idea that they need to operate at a tactical level, but the technology isn't yet available to them. Very few people manufacture true OOB solutions that are truly covert.

OOB is primarily intended for use in tactical situations when facing an opponent equipped with current-level Gen3 technology.

David.

Reading a thread like this makes me feel woefully uneducated. Why haven't you guys solved the problem of time travel or moving at the speed of light? Lol.

Sorry I wasn't speaking of the new gen 2 stuff they are putting out.  I have no experience with that.  I assumed this was a buy newer gen3 tube or older cheaper gen 2 tube since we are on to omni 8.  If you try and resale you would be hard pressed to get the same for gen2 as you will for 3.

Would you want to take the guessing a step further? I have no knowledge how multialkali photocathodes are mixed, but due to how the front surface of the photocathode seems to do some bending tricks, could the mix consist of small granules of different materials placed exactly where they need them?

Some time ago I asked the same question, but regarding camera sensors. Would think it could be doable to not lose 1/3 of efficiency on the bayer filter if you had a system like that in front of the sensor.

Cuz those are hard problems . Then again NV was a hard problem in yhe first half of the last century... The "theory" of what led to NV is actually what got Einstein his Nobel Prize in 1921...

You gotta be clear, we are a rough crowd..

No selling in tech.... <coctailer>

...