Night Vision 101
Night Vision 101
How to Get Into Night Vision
Night vision is an incredibly awesome tool that is becoming increasingly popular in the shooting, hunting, and law enforcement communities. Although night vision is incredibly fun and useful, it can be intimidating to get into. There are tons of options, terms, and misinformation that makes it difficult for the consumer, whether a professional end user or a enthusiast, to decide what they need and how much it should cost.
Night vision gives users the ability to see in the dark. This is accomplished with image intensifier tubes. These tubes are manufactured in two general categories of finished goods, clip-on night vision and helmet mounted night vision. Under these two broad categories there are tons of options with vast ranges in price. However, these two broad categories have two basic subcategories, the housing and tube or tubes. Essentially the housing is what you see on the outside. The housing is the “model” of your night vision. Then your tube or tubes are installed into the housing to give your unit life. We will break it down in a few categories that buyers should keep in mind when deciding what night vision.
The image intensifier tube(s) is the heart and soul of your night vision device. The tube is what is inside your housing that actually give you the ability to see in the dark. Image intensifier tubes have a few differences, however, there are three basic categories that are often given to buyers to choose from. Those are autogated / non-gated, filmless / thin-film, green / white phosphor.
Autogating is the process of the tubes power supply rapidly controlling the amount of power to the tube receives, thus increasing or decreasing the sensitivity to light. This happens at an extremely fast rate. In most cases, we only recommend autogated tubes. Autogating will extend the life of the tube and help protect it from light damage.
Filmless versus thin filmed tubes is always a topic of what is better. Filmless tubes will perform better in most instances than a comparable thin-filmed tube. Filmless tubes have better light transmission and handle high light and extreme low lights better than thin-filmed tubes. However, with that being said, thin-filmed tubes are slightly cheaper and still are great performers. It is important to understand that tubes are like diamonds, no two tubes are the exact same and all perform slightly differently.
Last is the biggest debate on the internet… GREEN OR WHITE PHOSPHOR? It is very important to understand that although there are some performance benefits to white phosphor, the color of a tube is simply the phosphor used. There are very bad white phosphor tubes and very good green phosphor tubes. The number one misconception we see from customers is assuming all white phosphor is better than green phosphor tubes. There are still very low spec white tubes being sold. This is why tube specs are important. With that being said, when looking at a green tube and white tube with comparable specs the white phosphor is much better. The white phosphor produces an overall better image. The image appears cleaner and more detailed. Shadows are also easier to read and do not blend together as much as with green phosphor. These benefits produce an overall superior image.
Housings are broken down into three main categories: monocular night vision, binocular night vision, and clip-on night vision.
A monocular is a single tube that is intended to be helmet mounted and cover a single eye. The most well-known and widely accepted monocular is the PVS-14. PVS-14’s are extremely cost effective, versatile, and rugged. Depending on tube, components, and specs they typically range from $3k-$5k.
Binocular night vision is a helmet mounted solution that covers both eyes. Although binos are significantly more expensive than a monocular, the performance gains are definitely worth it for most applications. Having both eyes aided is much easier to adjust to the night vision and provides better perceived depth perception and field of view. Although the field of view and depth perception is no different than a monocular, the brain interprets the visual information easier when both eyes are aided. There are tons of binocular housings on the market but in general they all are either fixed bridge or an articulating unit. We have an article breaking down the differences below.
Finally, clip-on night vision is night vision devices that are designed to be clipped on the rail of your gun in front of your day optic. Clip-ons provide the shooter the ability to use the same gun for both day and night and not switch optics. There are several different models of clip-on night vision on the market. When looking at quality clip-ons what mainly separates them is tube, magnification range, and recoil rating. We recommend looking at the needs of the platform and prioritize what magnification range and recoil rating is needed. This then helps narrow down what tube will work best for the intended distance and environment.
Helmet Mounted or Clip-On?
Unless there is a specific need for distance or LE application, we typically recommend that buyers start with a helmet mounted solution. The reason for this is the nature in which clip-on night vision devices are designed to work. Clip-on devices do just that, they clip-on the rail in front of the users day scope to provide night vision. The user looks through their day scope and through the clip-on in front of their scope to see. Although this provides variable magnification capability, the huge downside of a clip-on unit is the user must point a gun at whatever it is they are trying to see. This could result is pointing guns at things that we do not want to shoot. Because of this we recommend that buyers typically start with helmet mounted night vision, as it lets you scan and see hands free without having to have your gun pointed at what you want to see. Once you decide helmet mounted or clip-on you can further break it down to more specifics.
Articulation VS. Fixed Bridge
One of our main goals at Licentia Arms is to educate our customers and help them make an informed purchasing decision. While helping customers select their night vision one of the most common questions is, “should I go articulation or fixed bridge?”
To answer this question, we must first understand the difference between the two. Fixed bridge binocular night vision is a housing where the optical pods are attached to a fixed bridge and do not rotate out. On fixed bridge systems the inter pupillary adjustment (the distance of the pods from each other to properly cover the eyes) is adjusted with thumb screw to move the pods in either direction on the fixed bridge. The most popular example of this is the RNVG (Ruggedized Night Vision Goggle).
Articulating night vision goggles still have two optical pods that cover both eyes; however they are adjusted very differently. Articulating goggles do just that, Articulate! Articulation is where the optical pods pivot on the bridge both out and in. This is for two reasons… first to give the user adjustability for proper inter pupillary distance and for snag free stowing of the night vision. A great example of articulating goggles is the DTNVG or PVS-31. Although these are very different systems they both articulate on their bridge.
Now that we understand the difference between the two, we can discuss the pros and cons of both types of binocular night vision… for ease of showing the differences we will list them below. One important note, for the purposes of this article we are focusing on ground optimized, up armored units. It is important to note that while the popular Anvis goggles are a fixed bridge system, they lack the inherent ruggedness discussed below.
- Ruggedness by design: By eliminating the articulating joint, fixed bridge designs eliminate the inherent weak points of an articulating system. This means an all over more durable unit.
- Speed: Since fixed bridge units do not have the ability to pivot the optical pods away from the users eyes, they do not have to be individually adjusted each time to get the pods perfectly in front of the users eyes. This means that they can just be flipped down on the mount and they are right where they need to be.
- Slim design: Even though fixed bridge goggles do not fold back toward the helmet they are generally have an overall slimmer bridge for a nice compact package.
- Height when stowed: Because of the fact that the optical pods do not articulate out the unit must be flipped up on a helmet mount to stow the goggles. This makes the footprint of the helmet taller and can hit the ceiling of vehicles.
- Lack of stowing options: Fixed bridge goggles only move horizontally on the bridge via thumb screws. Because of this the user has to manipulate the helmet mount if they want to scan with a thermal or go unaided.
- Flexibility: Articulating units give the user a lot of flexibility when it comes to how the unit is ran. Users can run the system with both eyes aided, no eyes aided, or only one eye aided. This is helpful when using a handheld thermal or reading ambient lighting conditions.
- Features: Most articulating units have either auto off when flipped up (PVS-15 & PVS-31) or each optical pod independently shuts off when stowed (DTNVG). This prevents damage when not in use.
- Ruggedness: Although most modern goggles are very sturdy an articulating unit is typically inherently weaker than a fixed bridge design like the RNVG. This is because the joint where the articulation happens is exposed and not as rugged as a contained fixed bridge system.
- Price: Articulating units are a more complex housing, so they are typically more expensive than most fixed bridge systems.
- Adjustment: With most articulating units not having IPD stops (inter pupillary distance), the user has to readjust the inter pupillary distance each time they rotate the optical pods. This could take some tweaking to the unexperienced user and take additional time than simply flipping down a fixed bridge system.
There is no right or wrong answer to which system is best for you. We recommend the style of goggle that fits your needs and the style you prefer. As a general rule, if you need to be in an out of vehicles or are scanning with a handheld thermal then we recommend an articulating goggle. If you are a civilian that uses your goggles on the flat range we say go with what fits your needs and priorities best. Both are great options, and both have a place in the market. Do your research and buy informed!