NVG Binocular Buyer's Guide - 2023

NVG Binocular Buyer's Guide - 2023

CHS now offers over 10 different binocular options and we thought it would be handy to summarize the key differences between all of these options as well as provide some thinking/discussion points to guide your decision.

We've captured all of the key features and differences and these can be viewed via our online spreadsheet HERE.

It can also be downloaded in PDF format HERE.

Fixed Bridge vs Articulating

This is most likely the most divisive and key decision you will make. Fixed bridge systems are typically stronger and more robust compared to their articulating counterparts due to the lack of a hinging mechanism. A particularly notable advantage of fixed-bridge binocular systems is that they are easier to work with generally speaking - to move the binocular out of view is typically done with a single motion via the NVG mount. Restoring night vision is also easily done and will always put the goggle in the exact same place every time. This simplicity has huge benefits in terms of repeatability and having less moving parts to actuate. Anybody who has tried to execute multiple tasks with and without night vision will appreciate the fewer steps required to use and stow fixed-bridge goggle systems - it's actually one of the advantage that ball-detent systems like the AVS6 and AVS9 systems have there operators would flip the goggle up and the ball-detent mechanism would immediately power the goggle down - simplicity is speed.

Conversely, articulating goggles have grown in popularity in recent years initially driven by the popularity of first the PVS-15, then PVS-31A and more recently the DTNVG/DTNVS. Since then a myriad of articulating system have sprung up. Articulating system have benefits such as the ability to roll individual pods out of the way (useful for admin tasks or if needing to have one eye use a thermal sight, as an example), and also stow the pods closer to the helmet to reduce perceived weight (due to reduced length of moment arm between the goggle's centre of gravity and the base of your neck. For those of you who remember Grade 10 Physics class - Torque = Force & Distance. Force in this case is gravity and if you reduce the distance between the base of your neck and the goggle, you otherwise would reduce the perceived "torque" felt by your neck and trap muscles). A lower profile goggle and helmet systems makes getting in and out of vehicles and low-hanging structures easier, so if those are use-cases specific to your application, articulating goggles may be worth exploring further.

Manual Gain vs Auto Gain

Most binocular systems on the market today do not feature manual gain primarily due to increased complexity (both from a manufacturing and a user perspective) and the fact that integrating a MX-11769 format variable-gain intensifier with pigtail has historically proven challenging or cost-prohibitive for housing manufacturers. However, with the introduction of 3-pin or 3-pad MX-10160 format intensifiers, the removal of the need to accommodate for a physical tail has made manual-gain goggles become more popular recently. Notable examples include the forthcoming Manticore-R and Samurai-R

Manual gain can be beneficial in situations where the contrast between high and low light areas of an image need to be reduced (eg: urban areas). In these situations, the gain can be reduced so that objects behind a window (as an example) can be seen against a brightly-lit exterior. The ability to manually change the gain should be weighed against the practicality of adjusting throughout your use of the device - simply put, you may not want to dial your gain level perfectly for a specific scene, then enter a structure, and have to manually adjust your gain again. That being said, manual gain can be beneficial for lower-cadence, recce-type roles where the user can afford time to adjust gain to the desired levels. 

A recently popular attachment that provides a pseudo-manual gain option to auto-gain devices are the adjustable iris aperture devices (such as our CHAD) that can be attached to any device's ocular lens. The principle is quite simple - by closing the aperture, you reduce the amount of light entering the intensifier and essentially create a very easy-to-use manual gain "knob". However, the downside is that you have to actuate each optical channel individually so the experience is not as seemless as a system-wide gain control.

Pod Auto-Off

A feature that's unique to most articulating binoculars is the ability for each optical pod to shut off power to the intensifier when the pod is rolled out of view. We believe this is a critical function for three reasons:

  1. Reduces light backsplash against the user's helmet/face when the intensifier is not in use (essentially reduces visual signature for near-peer adversaries);
  2. Reduces the number of steps operators must perform when the goggle is temporarily not being used;
  3. Reduces the chances of damaging the intensifier from bright light sources when the device is not being used. (eg: when moving from a dimly-lit area to a brightly-lit area). 

Note that not all binocular systems currently on the market have this feature (PVS-31A, BNVD-1431), but all of the systems we currently offer do.

Material Choice - Durability

This one is simple - do you value weight over durability? Typically metal-based housings such as the RNVG, RNVG-A, RPNVG, Manticore-R, Samurai-R, and Proton will be slightly heavier than their polymer-based counterparts (eg: Katana, LLUL-21, Aeternus, DTNVS), but offer a substantially higher level of durability. That being said - metal housings will typically impart more impact force onto the intensifier vs polymer housings which would absorb impacts and potentially break. But it is usually far cheaper to replace a broken housing, than replace intensifiers damaged by impacts. 

System Weight

Another key consideration is system weight. Most binocular night vision systems that are assembled with milspec optics will come in between 500-550g with some outliers above 580g. Most users will find systems weighing more than 580g to feel cumbersome despite having a properly balanced helmet setup (via a helmet counterweight) as a heavier system will have a higher perceived "swing weight". This is a consideration due to the narrow field of view (FOV) of night vision and the need to constantly move your head. Some of these heavier binocular housing weights can be offset via lightweight optics but at both a higher financial cost and optical performance penalty. (See our article regarding lightweight lens systems HERE). This approach can be problematic as the cost-savings associated with heavier housings such as the BNVD-1431 or PVS-31C are essentially negated by the cost of the more expensive lightweight lens options, creating a paradoxical situation where you end up with an average system weight, but at a higher cost and lower optical performance.

As the prevailing performance of US Milspec lenses is still superior to lightweight options currently, shaving housing weight has become a popular (and preferred) avenue for users to reduce headborne fatigue. Housings such as the DTNVS, Katana, and LLUL-21 all feature significant weight reduction and come in around 460-510g. While the Katana and LLUL-21 achieve weight savings through design, and elimination of some features (IR illuminator, internal indicator lights, etc), the DTNVS offers a robust feature-set at a similar low weight. While durability has always been a concern for lightweight housing options, forthcoming and current metal-based housings like the Manticore-R, Samurai-R aim for a total system weight of 550g and should be considered as they become available.

On- vs Off-Board Power

While the concept of remote battery packs are not a new concept (AN/AVS-6/9's operated exclusively on offboard rear helmet-mounted battery packs), most consumer, ground-based binocular systems will have onboard power of some kind. Recognizing that most binocular night vision systems will require a helmet counterweight to balance the helmet, recently-released housings such as the LLUL-21, and Samurai-R have disrupted the market by moving power exclusively to the rear, and in the case of the Samurai-R even the the controls are rear-mounted. This relocation of the power to offboard has a tangible weight reduction with both of these systems weighing in at least 60-80g lighter than their on-board power counterparts. It should be noted that while some binocular systems that have onboard power with an optional offboard power option, this particular type of setup does not yield a significant functional weight savings as the weight of the battery receptacle is still present. Most offboard power options will power binocular NVGs for 24 to even 80 hours at a time without the need to change batteries so for those who will be out for extended periods of time, or those looking for a functional counterweight, off-board power may be worth exploring further. For most individuals onboard power is still the most popular option from a cost and complexity perspective.

On-Board IR Illuminator

Recognizing that most goggle-based IR illuminators are anemic at best in power output, some recent lightweight binocular options such as the Katana, Aeternus, and LLUL-21 have abandoned this feature altogether. Most NVG users will typically carry a much more powerful on-person or on-platform supplementary illumination making on-goggle illuminators redundant. That being said, the Boson Proton has two VCSEL-based illuminators can can output up to 500mW of IR illumination via its spot and illuminators (for reference, a full-power PEQ-15 illuminator outputs 30-50mW) that rival dedicated IR lights. 

On-Board Indicator Lights

Another area of weight savings are onboard indicator lights for low-battery warning and IR illuminator indicators. As mentioned earlier, most NVGs will run for 16+ hours on on-board power and even more on off-board power, so with a bit of battery management, one can simply keep track of how much time is spent with a battery and swap as that timeframe approaches. Users can also insert a fresh battery prior to mission-critical moments to ensure that there's no power issues that may potentially occur. Alternatively, most goggles have easy-to-access battery compartments that can allow for quick battery changes without dismounting the goggle. Secondly - as the user can typically see whether or not the IR illuminator is on - there is no longer a reason to include an IR illuminator indicator light. 

This Buyers' Guide will continue to grow and be updated as we add more options.

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