FPNI nails it.

For $500ish more get a brand new PVS-14...more than worth it IMO.

If you get a 7 you’re going to wish you had a 14.

And someday you can get a second 14+brigand voila:  duals.

My bad, should have said $600:

TNVC:  NGI/PVS-14-XLS Gen. 3 Thin-Filmed White Phosphor MNVD (Elbit USA Tube) × 1 for $2,350.

Granted, it was a special sale, but never to be done again?  Who knows.

I guess it comes down to how you will employ the unit.

If you plan on doing any shooting, the 7 is the least desirable of all the systems I have used (5, cutaway 5, 7, 14, GPNVG).

The Litton 7A/Cs are a little bit of a wonky housing. Parts will be rare and possibly expensive (though also possibly dirt cheap because no one wants them... just depends on the seller) and IIRC a little bit more delicate than the B/Ds--the long and the short of it being that the B/D was more or less designed for Army ground use, versus the A/Cs, which were more common with the Navy, Special Operations, etc.

IMHO, if you can get a PVS-7 for under $1,500 (or less, depending on the tube) and you have no other night vision, want a spare set, want it now, etc., then it could be a decent buy. As others have pointed out, it will allow you to see and move at night, and that is advantage #1 of night vision. While some may take issue, $1,500 is kind of "throwaway money" in the NV world, and ~50% of the cost of a new PVS-14, so it could be worth that, even just to tide you over until you can get a 14 that you can keep as a loaner or spare.

Over $1,500, I would pass--as others have pointed out, you can save a little more for a new PVS-14, or used PVS-14s come up periodically across a lot of price ranges. A PVS-14 will be more versatile and more useful in more situations than a PVS-7, and the weight and complexity (to say nothing of resale) generally make them a poorer investment, and the tube can't even really be re-purposed for something else as most MX-10160 and 11769 tubes can be, the 7 really is kind of a one-trick pony.

Another disadvantage of the biocular design used by the PVS-7 is that it essentially "tricks" your brain into thinking that you have stereoscopic vision, which inexperienced users may find more comfortable, especially in the beginning, however it creates a distorted spatial awareness that means you cannot judge depth or distance as accurately because the normal binocular cues and disparity don't exist as the PVS-7 is simply using a beam splitter to duplicate a single image.

The only real application in which the PVS-7 has somewhat of an advantage is in astronomy, where you can stick the device into your telescope and use both eyes to observe, but that's a pretty niche application.

~Augee

For static observation, perimeter security, fixed defensive position, etc., thermal is probably a better choice than image intensification, enough so that it's worth having a PVS-14 (which can also use the 3x magnifier) just so you can pack a bigger/better thermal.

I spent a lot of time doing a lot of "Army shit" with PVS-7s.

I would argue that night fighting tactics were a good bit different when "door kickers" were using PVS-7s. Some special operations units went almost directly from dual-tube PVS-5s to dual tube AVS-6(v)1s.

Those were the days of overhead illumination flares, M845s, SIMRADs, and the like.  

For sure, GPF was using 7s well into GWOT and they are still in circulation today, but the days in which they were "top of the line" units for ground combat forces was fairly limited, and tactics were much different.

While the AN/PAQ-4 was in limited use since at least 1980, they were fairly rare until the advent of the PAQ-4C, and by the time conventional infantry units started receiving them in numbers, the transition to PVS-14s wasn't far behind.

I've rolled out of Bradley and Stryker ramps with 7s, I've hitched M16A2 stocks up on my forearms to train MOUT and CQB and know my iron sight "point shooting" techniques and remember when you yanked the doors off the 1025s for recce and if they came with seat belts, I didn't know it. And it's not because I'm very old or even very experienced compared to many, but gear and tactics can take a while to circulate. I remember one of my first units we had an older E7 who had gotten his CIB with 10th Mountain in Somalia in '93, and he was venerated as having "been there, done that." Not that anyone lost any respect for him, but having a CIB soon started being a lot less special.  

The PVS-7's heyday was a slump of late-Cold War theory, budget cuts, and little "engagements" here and there, and a lot of old theory based stuff went right out the fucking window when proofed in real combat. And while I'm not the guy who will sit here and tell you "you'll get killt in da skreetz" if you're using a PVS-7, this is the space that the PVS-7 occupies in my mind.

Have guys used them to good effect in the past when that's what they had? Sure. Those same guys lined the floors of their 998s with PASGT vests to prevent getting their nuts blown off. Just because it's been done and kinda worked doesn't make it a validated combat TTP or a combat effective piece of kit.

Actually, I see a lot of guys, mostly older, who either got out early or were never in, and not just in the NV world, cling to pre- and early-GWOT theory based ideas and continue to repeat, recommend, or insist on them, the old "well I heard from an old SF guy..." Not that GWOT is the final word on all things ground combat, however it's proven a fairly fertile testing ground for a lot of old theory based practices, and has slaughtered a good many sacred cows.

::shrug::

Ah, memories.



~Augee

@Steviesegal

Unfortunately the only way to really know what'll work for you is to get your feet wet. That's how guys find out if they like or hate the -7, prefer a single -14 or binos, white or green, etc. What works for some doesn't work for others and there's only one way to find that out.

Another option is find people who will let you demo their gear. If you can't do that, we have a demo program called "Try Before You Buy" where for $175 you get an entire night to try out PVS-14s, binos, different helmets & mounts (but no PVS-7's ). Info is on our site in the training section. Dates are limited so if you see one available you can make it to, sign up! You can also rent gear for Night Fighter 101 (pre-req's and info in same section).

One thing to consider - whether you buy a PVS-14 or PVS-7, new or used, if the bug bites you like it did most of us, you'll end up buying more NV. However, in the event that it doesn't bite you but you want to hang on to the device for SHTF, etc. then you want to make sure what you buy is decent so it's worth keeping.

Proper Link

ETA: because not everyone is going to read the whole damn thing. Note that the binocular & monocular used was a -5 (page 17) so take that FWIW as it relates to 2021 tech

Augee made an excellent post that is stickied^ but I'll throw it in here as well as it's relevant.

Original by TNVC_Augee

Given the frequency with which we field questions, here on the forum as well as via phone and e-mail, I thought it might be worth posting this simple illustration and explanation of binocular disparity/parallax, and how it relates to depth perception and NVGs.

There's a lot of variations on the question, but the crux of all of them pretty much end up being "why are Binocular Night Vision Goggles (BNVGs) better than/more expensive than other options?"

Note: this is not meant to try to convince anyone that they need to buy BNVGs and that monoculars or bioculars will get you "killt in da streetz," but rather an acknowledgement that both the difference in cost and the fact that so many professional end users and trainers use and advocate the use of BNVGs warrants at least some explanation of why they're better.

The common answer typically tends to be that BNVGs provide better depth perception, which then also translates to improved situational awareness, and allows end-users to move more quickly and more safely (important when operating vehicles and/or aircraft, as well as more "dynamic" dismounted activities). BNVGs also reduce user fatigue, allowing them to be worn longer, both in terms of overall duration, and the amount of time between when you need to give your eyes and a brain a "break."

Going into a little bit more detail, the primary mechanism by which BNVGs accomplish pretty much all of these is related to stereoscopic visual cuesour brains and bodies have evolved to use stereoscopic vision, common amongst active predators throughout nature.

One of the main stereoscopic cues is binocular disparity, illustrated here in a very simplified form:


Simply put, your two eyes provide slightly different angles of objects that you observe in three-dimensional space. Based on the amount of disparity between the two angles on an object, your brain can then unconsciously judge the distance from you to a given object or obstacle with a fairly high degree of accuracy, especially if you are familiar with the object or type of object (e.g., a couch or a coffee table) and its nominal dimensionsor if there are other familiar objects around it (e.g., tree trunks). The greater the disparity, the closer the object/obstacle, allowing you to distinguish between a small object nearby, or a large object in the distance, as illustrated in the bottom half of the image. Moreover these cues are not dependent on objects/obstacles being in focus.

Optical illusions like 3D images or stereograms ("Magic Eye"), and/or forced perspective scenes use binocular disparity to "trick" your eyes and brain into seeing (or in the case of some forced perspectives, not seeing) depth accuratelyin fact, you can actually "see" stereograms through BNVGs, thanks to the proper translation of binocular disparity.

Binocular disparity is one of the primary components of depth perception and stereoscopic vision, allowing you to proper gauge distance and relative size, making it extremely important while moving, especially at high speeds and over unfamiliar terrain/environments.

With a monocular, depending on the amount of ambient light, you can get a degraded version of these stereoscopic cues using information from your unaided eyewhen there is enough ambient light, your unaided eye can at least get some information about objects and obstacles, allowing you to have some sense of depth perception.

This is why manual gain is considered so important in monocular night vision devices, while being less so in BNVGsif the difference between your aided and unaided eye is too great, your brain can "turn off" your other eye, preventing you from "seeing" and processing supplementary information being provided by the unaided eye. Therefore the ability to dim the aided eye to better "equalize" the inputs from your two eyes can be extremely important. With a BNVG, since both aided eyes will have equal or close to equal inputs to provide stereoscopic visual cues, manual gain control tends to be considered less important with BNVGs.

Moreoverthis is why monocular night vision devices by far require the most training and practice to learn to use effectively, and why many novice users find biocular devices like the AN/PVS-7 family to initially be "more comfortable" and easier to use.

On the other hand, biocular devices, as a function of their design and operation CANNOT provide binocular disparity, as a single image from a single image intensifier tube is being projected into both eyes.

In doing so, biocular devices "trick" your brain into thinking you still have stereoscopic vision, making you "feel" more comfortable, simultaneously making you more confident, when you are in fact less able to accurately judge distances, making them a greater liability.

The element of "comfort" provided by the biocular image has often times caused them to be "preferred" and recommended for vehicle drivers, however, IMHO, this is a mistakeas the "preference" of many novice night vision drivers for the AN/PVS-7D has everything to do with psychological factors, but actually provides poorer potential depth perception than the AN/PVS-14shameless plug, but this was one of the main driving reasons behind the development of the TNV/PVS-14-PBM-A, to provide conventional military drivers without access to BNVGs with a binocular capability.

Furthermore, stereoscopic visual cues also help to explain some of the importance behind proper collimation and interpupillary distance (IPD) adjustments:

In terms of collimationwhen photons enter the image intensifier tube, they do not necessarily travel in a straight line to the eye, the design of image intensifier tubes almost guarantees that there is a slight amount of shift in the image. Collimation involves ensuring that the image shift between eyes is within acceptable tolerances.

This is also in part why boresighted and collimated devices like Clip-On Night Vision Devices (CNVDs) are so much more expensive and complex than normal NVGs (the catadioptric lens assembly is another big partbut that is a topic for another time). It's worth noting that the acceptable image shift tolerance for an MX-11769 image intensifier is about three times that of an MX-10160 "aviation" style image intensifier, and hence why we prefer not to perform tube "conversions," even with L3Harris image intensifiers with removable EGACs, they're "out of spec" for most binocular devices, and much harder, if not impossible to collimate properly in a binocular system.

Can you use an uncollimated or poorly collimated BNVG? Sure, and it's better than a monocular or a biocular, however it's still not ideal, and not the same as a properly collimated set of dedicated BNVGs.

At the same time, for aviation applications, both the U.S. military and FAA require extremely strict inspection standards to ensure that BNVGs are within tolerances, as a minor misjudgment in an aircraft can have catastrophic results.

This repeatable, consistent image shift is also why repeatable, consistent IPD can also be an important factoryour brain is used to a certain distance, i.e., a certain amount of shift between your left and right eyes, and will use that "known quantity" to judge the value of binocular disparity in judging depth and distance.

When learning to use BNVGs, to a certain extent your brain has to "re-learn" the relationship between your left and right eye to give you the most accurate and reliable information, especially when combined with the image shift induced by the image intensifier tube, which is ultimately almost impossible to reduce to zerohence why there is an acceptable and unacceptable tolerance.

A non-repeatable, non-precise IPD can have an effect on binocular disparity, especially when coupled with image shift in the tubethe affect may be minor, but it's there.

Again, this is the reason that despite the increasing popularity of articulating goggles for ground applications, almost all aviation goggles utilize a fixed bridge system with precise and repeatable IPD adjustmentsat very least with a fixed bridge, the image shift effects are limited to the horizontal plane, rather than an offset rotating axis relative to one another with an articulating goggle design.

That being said, this is not meant to be interpreted that articulating goggle designs are terrible and you shouldn't use themthere are some benefits to articulating goggle designs, otherwise they would not be so popular, however, in keeping with our mission of education and providing information to all potential end-users, it is worth discussing the potential pros and cons of certain configurations and design philosophies and understanding the benefits and limitations of each.

The reality is that in many situations and to many end-users, the differences between these minor factors may not make any practical difference at alland the vast number of goggles out there that have been built without proper collimation can certainly attest to thathowever, this does not change the fact that there are right and wrong ways of doing things, and better and worse approaches, nor does it foreclose on the possibility of minor issues "stacking" to create a bigger problem.

Finallyin terms of user fatigue, again, the basic concept is fairly simple:

Your eyes and brain have evolved to operate a certain wayand while modern NVGs can't exactly replicate our natural vision, properly built and configured BNVGs tend to get the closest, meaning that they are more "natural" to use, and therefore more comfortable to use for prolonged periods of time.

The more deviations from "perfect," the more your brain needs to work "overtime" to process the inputs and resolve them into useable information, which ultimately leads to user fatigue.

With bridged monoculars or an uncollimated and/or improperly adjusted BNVG, your brain can resolve stereoscopic visual cues, but will have to work harder to do so, leading to accelerated fatigue compared to wearing dedicated BNVGs.

With a single monocular, you can get a degraded version of the stereoscopic visual cues, but you will fatigue much more quickly as your brain strains to resolve the widely disparate information it's receiving from your two eyes.

With a biocular, you will probably experience less fatigue and be much more comfortablearguably even more comfortable than with a BNVG, as you're not experiencing the disparate shift from two different tubes, however you will not have any stereoscopic visual cues making you less capable of accurately judging distance and depth.

TL;DRDedicated, collimated BNVG > bridged monoculars > single monocular > biocular.

P.S. often people will recommend the purchase of a "low cost" PVS-7 as opposed to a PVS-14 as a way to "get in to" night vision. This is not bad advice, and I've given this advice to more than one person in the past, because having night vision is infinitely better than not having night vision.

However, it's worth noting that the only reason that PVS-7s are so "cheap," is not because they're inherently cheaper to producein fact they are much more complex and difficult to assemble than a simple monocular system, with prisms and 50% more optics (eyepiece assemblies) than a monocularthe image intensifier price is about the same, but simply put, because very few people want them.

The "new" price of a biocular device to manufacture or assemble is actually higher than a monocular, they're sold cheap because otherwise nobody would buy them.

Okay, that's what I've got for now.



~Augee