Dual Tube Night Vision Buyer’s Guide
After the positive feedback I received from the last article, I wanted to dive more into the options available for people wanting to either upgrade their current single tube (monocular) setup or dive straight into a dual tube setup (binocular). This article will touch on the most common binocular setups available on the market and their pros / cons. Prices vary greatly depending on tubes, but range from $5,000-$14,000. If you have not had a chance to read my previous article and want to learn more about tube specs and equipment, please read that here before continuing. If you like these articles, check out the rest of the site and follow us on Instagram @themenwithgreeneyes.
Benefits of Dual Tube Setups Vs. Single Tube
Other than looking cool, what are the benefits of running a binocular vs a monocular? First, we must think about how we see things when we are not using night vision. The brain is programmed to see out of both eyes and combine them for a usable image. When using a monocular, you are seeing two distinctly different images which your brain will compensate for and combine in your mind’s eye. However over extended periods of time, this can lead to headaches and eye fatigue.
With any night vision, your natural depth perception will be decreased because the image projected from a NVG is further out from your natural vision line. A monocular setup projects two different depth images into your eyes which can cause eye strain. The human brain does a good job at compensating for this, but depth perception with binoculars will be better for activities such as running or driving.
By having a device with two different tubes you get the benefit of a failsafe. If one tube fails, you will not lose all your night vision abilities.
A common misconception is that a binocular setup will give the user increased field of view (FOV). Unless you are using a panoramic setup which we will touch on later in this article, both a monocular and binocular provide the same FOV in most instances this is ~40°.
Types of Binocular Housings
There are currently quite a few options on the market for binocular night vision. Before we dive into device specific information, I want to explain a few types of binocular housings / setups currently available:
Fixed– refers to a device that does not allow the user to change the vertical or horizontal angle of the tubes.
Articulating – refers to a device that allows the user to adjust the cant of the tubes. e.g. flip the binoculars to the side. This feature tends to be found on the higher end housings with some exceptions.
Panoramic – Refers to a relatively new type of binocular setup that allows the user to adjust the horizontal angle of the tubes to provide the user a wider FOV than available with fixed or articulating setups. 
Housing/Setup options
This section will be broken down into three parts: fixed housings, articulating housing, and panoramic options. I will not cover every possible option in each of these categories but will do my best to go through all the commonly available devices.
Warranty
Binocular configurations are expensive, so you may be wondering about warranties. These vary based on the device and supplier. Because it varies, I will not include these in the descriptions, but once you pick the housing you want, make sure to shop around.
Fixed Bridge
ANVIS-6 / ANVIS-9
I briefly talked about these in the previous article as being a very good option for a budget bino setup. This fixed bridge device was developed for U.S. Aviators to carry out night missions. It features a fixed bridge, ball detent mount (different from all others discussed) and tends to have a lower price point than other binocular options. It is important to note that due to it being designed for pilots who are stationary in cockpits, it was not designed to be as rugged as other devices and will be more prone to housing malfunctions if used in a more dynamic environment.
RNVG (Ruggedized Night Vision Goggle)
The RNVG has very similar controls to a PVS-14 which makes it a great choice for users who are already familiar with the PVS-14 controls. RNVGs can run off either a CR123 battery or an external battery pack. They are a very common entry level binocular device. One thing to note is due to the materials and lack of articulation to make it “ruggedized” they tend to be a bit heavier (555 grams) than the other devices mentioned.
LLI Aeternus
I will acknowledge that I am a bit biased towards this device as it is the one I am currently running. The Aeternus is very similar to the RNVG with a few updates. They removed the IR illuminator to reduce weight and increase battery life, as well as replaced the PVS-14 style on / off switch with a push button. They utilized hardened polymer instead of metal to achieve a similar ruggedized goggle at a lighter weight (535 grams). One very cool program that LLI has is the ability to trade up to their articulating housing for just the cost difference of housings (~$550). They will swap the tubes and rebuild the new device free of charge.
ABNV MOD-3 Bravo
These are cool. I haven’t had the chance to personally use them, but they seem like an interesting housing. My understanding is that these are essentially a RNVG that has detachable pods which (with a monocular adaptor) the user can split in half and lend to a friend to effectively turn a binocular into two monoculars.
Articulating Housing
PVS-15
The PVS-15 housings have been discontinued and sourcing parts is difficult. Was originally designed for USSOCOM. They are clunky (652 grams) and outdated but can be a good option to get a binocular with articulation at a lower price point. Has a built-in illuminator and controls like that of a PVS-14. 
BNVD 1431 MKII
The 1431 MKIIs are a popular option for a modern, less expensive articulating binocular. The MKIIs feature an onboard illuminator and the option to use either a double-a or an external battery pack while remaining relatively lightweight (590 grams). The downside of the MKIIs is they have been reported to be more fragile than other binocular devices especially at the articulation point that have failed when dropped. These are an improvement on the MKI which were much more prone to breaking. It is important to note that this is a Chinese housing produced by Argus. 
LLI LLUL-21
The LLUL-21 is LLIs articulating binocular. This is relatively new to the market, and is a lightweight (460 grams) binocular with Individual pod on/off, IPD stops, and an external battery pack only (to reduce weight).
UANVB Katana
The Katana is very similar in design to the LLUL-21, but has been on the market longer. It features everything the LLUL-21 does except it can run an onboard battery that gets rid of the need for wires. They are also considered very lightweight (413 grams). 
PVS-31
The PVS-31 is currently used by special operations and LEOs around the world. There are many iterations of the PVS-31, but I will discuss the most common available to civilians, the PVS-31A. They use proprietary tubes, no adjustable diopter but can be swapped, and proprietary objectives with built in, but removable sac lens. It runs on either a double-a battery or can use an external battery pack with 4 double-a batteries. The PVS-31A lacks some features that the previously mentioned units have such as individual pod shutoff. It is a lightweight design (453 grams W/battery, 430 grams W/O) . Price to value is typically low for this unit.
DTNVS
The DTNVS has recently gained a lot of popularity. They have most of the features of a PVS-31 except manual gain, IPD stops, and you need an adapter to utilize a battery pack. They typically run around $2,000 cheaper than a PVS-31. Weight (441 grams). 
Other Options
There are quite a few new exciting binocular devices on the horizon that haven’t been mass released to the public (Boson, UANVB Samurai, ARNVG), but due to lack of availability, user testing, and specs I felt it was not realistic to go over them in this article. It will be interesting to see how they stack up when they become more common.
Panoramic (Pano) Bridge
Pano bridged units are available for dedicated dual setups or traditional mono setups. The allure of a pano setup is the ability to increase field of view (FOV).
Bridged Tantos / PVS-14
Bridging two monoculars together using either the Noisefighter Panobridge or a knockoff is a cheaper way to achieve this increased FOV. The downside to this is it is typically heavier and requires the user to manipulate two controls.
RPNVG
In the fixed bridge options, we examined the RNVG. The RPNVG is a modification of the RNVG that allows the user to gain a pano view in a singular dual tube housing.
Conclusion
After reading this article you have probably realized there are a multitude of options available for a binocular setup. It comes down to personal preference, budget and use case.