Month: April 2016

Monoculars

Reviews of the Best Night Vision Monoculars

Good night vision is something that we humans lack. As such, we must supplement our lack of night vision with tools. This technology may seem to be only of use to those in certain professions such as law enforcement or the military. However, there are many other situations in which night vision can be helpful.

When camping out in the woods, night time movement is sometimes required. While flashlights can be used, they only serve to illuminate the path in front of you. Having night vision would make it easier to identify what’s around you and where you can safely walk. The same is true for those who like to spend time looking at nocturnal animals.

Those who like to hunt or fish at night will appreciate the advantages of having night vision when trying to spot the prey and when trying to navigate in the dark. Search and rescue teams working hard to find someone in the dark will find it much easier to navigate both by foot and by boat. Finally, those involved in security details (both professional and community) will find night vision the perfect accessory to enable them to clearly see potential dangers.

DEFINITION

Although there are many tools available that offer night vision, this document will focus specifically on the use of night vision monoculars. To define a night vision monocular we can clearly say that it is a tool that offers a single eye piece and a single objective. That description may be confusing so just think of cutting a pair of binoculars in half and you’ll get the idea.

That said, do not be confused. Binoculars serve to magnify the image we see. Night vision monoculars do not magnify the image. Instead, their goal is to provide an image of area and its objects at night. Most monoculars are lightweight and small. The most basic models are held in the hand, but the more advanced models can be mounted on a variety of objects. A definite advantage to using night vision monoculars as opposed to goggles is that one eye will always be adjusted to the regular lighting conditions found in the area. Another advantage is that the exposed eye maintains its peripheral vision. The downside of a monocular device is that is does not provide any depth perception.

METHODS

When creating an image of an object at night, we humans rely on two main methods. These methods are thermal imaging and light amplification (I² technology). Each method functions in a different way and creates a different end result.

We’ll start by looking at thermal imaging. Devices that use thermal imaging are basically seeing and measuring the amount of heat that is emitted by people, animals or objects in a given area. These devices are not optical (i.e. no eye piece), but instead use a sensor called a microbalometer to read the difference in heat between an object and its environment. This data is then displayed on a screen in an image called a thermogram for the user to see. No light is required. This technology is sometimes referred to as FLIR (Forward Looking Infrared).

Light amplification (I² technology) is different. It does not see or read heat. Instead, it takes the amount of light available and amplifies it. By enhancing the amount of light, this device can provide a clearer image of objects at night. Simply put, this device takes the existing amount of light and magnifies it. This is done via an image intensifier tube. In the most basic models, light packets (photons) are captured on a photocathode plate, magnified and then sent down a tube to create the final image. In more advanced models, the light packets are enhanced even further by the use of a second plate called the microchannel plate.

No matter which model you choose, all light-amplification devices need light to function. This light can be already existing in the environment and simply manipulated by the device or an additional infrared light source can be added to assist the device. Most of the time, the image created will feature the colors of green and black. These colors were chosen because they give the highest amount of detail. However, some devices will offer black and white images. Although these images do not have as much detail, they are definitely not as bright and therefore a bit easier on the eye to use.

One other factor that affects I² technology is something called blooming. This term refers to the whiteout or temporary blindness that can occur when a bright light enters the field of vision. New technology known as Auto-Gating can reduce blooming and its disruption of vision. This technology was originally only found on the most advanced models, but can now be found on some of the mid-level devices as well.

JUDGING QUALITY

When it comes to a thermal imaging device, consumers should consider one main factor. That factor is resolution. Basic devices will provide a decent image with only 240 x 180 pixels per square inch. Mid-level devices offer a resolution of 320 x 240 pixels. For hand-held devices, look for a resolution of 640 x 480 pixels. Note that when you increase the number of pixels, the price will also increase. Other high-quality features to look for include the ability to capture both still and video images.

Determining the quality of an I² technology device is not quite as cut and dry. First, one must consider the different generations of this product. Each generation (1 – 3) offers different technology and quality. That said, most of the time, the quality of an I² product is determined by its image intensifier tube. The resolution of an I² device is measured in lines per millimeter (lp / lpm). Most feel that 45 lpm will suffice for average situations. However, many people prefer a resolution between 64 to 72 lpm. One word of caution applies here. Don’t think that you can purchase a device with a cheap eyepiece and objective and just add a high-quality image intensifier tube to get a great product at a cheap price. To get the best quality, you will need to have high-quality parts in the entire device.

MAINTENANCE AND CARE

If you have a thermal system, the only rule is to not drop it. With an I² technology, the same advice applies. However, there are additional actions that should be taken to preserve the life of the device. Use a protective case when the device is not in use and be sure to remove the batteries before storing it. Lens covers should be kept in place until you are ready to use the device. Consider adding a protective layer to your optical pieces. A glass filter will help to protect the actual lens from damage and dirt.

OTHER OPTIONS

You can purchase a device that combines both thermal imaging and I² technology. However, these devices are very expensive and quite often highly sought after by the military. Thus finding one will be challenging at best. A new night vision technology is developing. This uses digital technology to provide an image. Functioning much like a digital camera, this device uses CCD chips and CMOS chips to gather light to create an image. In contrast to a standard I² technology device, these digital versions are cheaper and more compatible with cameras. They are also not damaged when exposed to bright light. That said, their level of performance is really on par with a basic I² model, but it is improving quickly.

GENERATIONS

FLIR (Forward Looking Infrared) devices, otherwise known as thermal imaging, are sometimes referred to as having generations. However, those terms are often used only in a military setting or in relation to the products produced by a company that uses the name FLIR. As such, there is no specific set of standards that determines the generations of actual FLIR technology for civilian use.

I² technology, on the other hand, has a very clear set of standards to delineate its different generations. The first generation, known as Gen 1, is the simplest type of night vision available. It offers technology from the 1960s and as such is the least costly option. Being Gen 1 means that the device only has a photocathode plate and a basic image intensifier tube.

GEN 1

Gen 1 devices need ambient lighting as least as strong as a full moon to function or they must be equipped with an IR illuminator to provide the necessary light. While adding this infrared light can increase the ability of a Gen 1 device to see in darker areas, it also means that the user is now visible to other night vision device users. Furthermore, these add-on IR illuminators are often quite limited in their power. Due to this, images are often not as bright and have a lower resolution.

Users can detect a human-size object located approximately 75 to 100 yards away using a Gen 1 device. Being able to clearly recognize what that object is requires a closer distance of 50 to 75 yards. Obviously, objects smaller than a human will require even closer distances in both the detection and recognition ranges.

Furthermore, Gen 1 devices are very susceptible to blooming. This image distortion caused by bright lights can make it impossible to see at times. The field of view on a Gen 1 device is also distorted with somewhat of a fish-eye feel on the outer third of the lens.

The device will provide about 1500 hours of use before any parts need to be replaced and Gen 1 devices are usually not mountable on any external device such as a hat or weapon. In addition, Gen 1 devices have a shorter battery life and require a few seconds to turn on and off. Nevertheless, they are often perfect for those who are considered hobbyists.

When purchasing a Gen 1 device, consumers should know that the following factors can affect performance: intensifier tube, size of objective, magnification level and the use of an IR illuminator. Consumers may see the term Gen 1+ as being of higher quality. However, that term simply denotes that the device is made using a currently produced intensifier tube, not necessarily a higher-quality one.

GEN 2

Second generation night vision devices (known as Gen 2) definitely cost more money than the Gen 1 options. However, for that money, you also get a better product. First, Gen 2 devices are much smaller than Gen 1 devices. That is due to an improvement in the plate technology. Second, Gen 2 devices have a second plate, called a microchannel plate, that further amplifies the movement of the light packets. With the addition of this second plate, the images from a Gen 2 device have better resolution and therefore are much cleaner and brighter.

The technology is still a bit old as it is from the 1970s, however Gen 2 devices require less ambient light and do not need the addition of an IR illuminator. The improved technology means that users can detection a human-size object from about 200 yards away and recognize that object from just about 100 yards away.

Other improvements include no fish-eye distortion and less blooming (distortion due to bright lights). Furthermore, a Gen 2 device has a longer battery life and can be mounted on a variety of objects. A Gen 2 image intensifier tube will usually provide about 5000 hours of use before needing to be replaced. Some sites will refer to a Gen 2+ device. Such devices were created when the Russians took our Gen 2 technology, copied it and then improved it.

As with the Gen 1 devices, the most important factor is still the type and grade of image intensifier tube that is used. Nevertheless, good quality lens are also a must for reliable performance. Some Gen 2 devices have also been improved with the addition of the Auto-Gating technology to virtually eliminate blooming.

GEN 3

In keeping with the old saying “You get what you pay for.”, purchasing a Gen 3 device will cost you money. However, you will also receive quite a bit of quality and technology for the cost. Using technology developed in the 1990s, these devices offer more than 10,000 hours of night vision before needing to be replaced. They use gallium arsenide in their image intensifier tubes. This product is expensive, but it also provides the highest degrees of brightness and accuracy in night vision images.

It functions very well in areas of low-light and does not need an additional IR illuminator. In fact, it operates well in all light conditions. Because of this, it is almost impossible to be detected by another night vision device user. With Auto-Gating technology included, a Gen 3 device has almost zero blooming and no image distortion.

It offers both detection and recognition ranges of approximately 300 yards depending on the model chosen and the conditions in which it is used. Gen 3 devices are extremely versatile and can be mounted on almost any product. In addition, there are plenty of accessories to add to the device to improve its function or compatibility even further. For all of these reasons, Gen 3 devices are preferred and used by the military. In fact, they are so good that they are not allowed to be exported outside the United States.

Sometime the rating of Gen 3+ is used. This is the very highest quality of Gen 3 available. Some people would like to call it Gen 4, but that category has not yet been given permission to officially exist. Trying to define a Gen 3+ is a bit difficult. In the past, it meant that the device had Auto-Gating. However, now most Gen 3 devices and some Gen 2 devices have that technology. One thing that still sets Gen 3+ devices apart from other Gen 3 devices is the lack of (or a greatly reduced) ion barrier. Ion barriers prevent the movement of electrons. Gen 3+ devices can operate with a much higher sensitivity to light compared to Gen 3 devices.

In Gen 3, as with the other generations, the type and grade of image intensifier tube used has the greatest impact. Those tubes that meet military standards are often referred to as “Mil-spec.” Some tubes fail to meet “Mil-spec” and as such are categorized as “Commercial.” In the “Commercial” grade, there are two divisions. Grade A means that the device has missed achieving “Mil-spec” in one standard. Grade B devices have missed meeting “Mil-spec” in several standards. No matter which type you choose, remember that the resolution offered is still the best predictor of image quality.

BEST OPTIONS

There are many companies that product night vision monoculars. Here is a list of some of the top manufacturers.

  • ATN
  • Armasight
  • Bering Optics
  • Bushnell
  • Firefield
  • Luna Optics
  • Night Optics
  • Night Owl Optics
  • Pulsar
  • SightMark
  • US Night Vision

BEST OVERALL MONOCULAR

Bushnell Equinox Z DigitalDigital Gen 1 products are becoming popular because they provide the quality of a Gen 2 device at the cost of a Gen 1 product. For this reason, our top pick is the Bushnell Equinox Z Digital. This product offers a 1-3x magnification and a 50 mm lens. Its viewing range is just about 984 feet and it comes with a infrared illuminator. It also comes with additional features such as image capture, video recording, daytime color and the ability to be mounted on a tripod. It features glass objectives, an adjustable IR brightness control and comes with a carrying case.

BEST NIGHT VISION MONOCULAR FOR THE MONEY

For the cost, the Bushnell Night Watch with Built in Infrared Monocular is a great option. This Gen 1 device has a scope that offers 2x magnification. It also comes with a rubber-armored grip and a built-in tripod mount. These last two features are somewhat unusual for a Gen 1 product. Rather than having to add an IR illuminator, this device comes with one already built-in. Its has a viewing range of 5-400 and is compact enough to slip into your bag. It comes with its own case and a lanyard for easy carrying.

BEST NIGHT VISION MONOCULAR UNDER $1000

Armasight Avenger Gen 2+ QSGetting a Gen 3 device for under $1,000 is almost unheard of. For that reason, we’ve chosen to recommend a Gen 2+ device instead. The Armasight Avenger Gen 2+ QS Quick Silver White Phosphor Night Vision Monocular provides advanced technology at a reasonably affordable price point. What makes this product a Gen 2+ is the ability to add high-performance Image Intensifier Tubes (IITs) using either Green Phosphor or Quick Silver. In addition to being able to enhance the product, this device can also be mounted on an object or carried as a hand-held device.As a standard Gen 2, it offers the resolution of 45 – 51 lpm and gives a magnification of 3x. Its lens is a wide 5 mm and it comes with automatic brightness control, automatic shut-off and a bright light cut-off system. It is water and fog resistant and can be adapted for use with cameras.

BEST NIGHT VISION MONOCULAR UNDER $500

Finding a Gen 2 under $500 is difficult, too. That’s why we’ve recommend a Gen 1+ instead. The Pulsar Challenger GS Super 1+ 3.5 x 50 offers lots of features that users will find helpful. First, it has a clear image that is free from any distortion across the entire field of view. Its Image Intensifier Tube is a CF-Super type that works with high-quality lens to accomplish this. It also has built-in magnification of 3.5x. The body of this device is completely sealed so that it can operate in virtually any weather condition. Like our previous pick, this device also has a built-in IR illuminator. However, it also offers a second mounting point to attach additional IR illuminators as needed. This Gen 2 device provides users with a few different compatibility options for use with helmets and googles. It comes with a power switch to prevent accidental powering. This device has a detection range of up to 750 feet and a lens of 50 mm. It comes with a carrying case and a built-in tripod socket for mounting.

BEST NIGHT VISION MONOCULAR UNDER $200

Firefield FF24063 Night Vision MonocularThe Firefield FF24063 4 x 50 mm Night Vision Monocular is definitely only a Gen 1 product. That said, for its price, it offers ample features. First, its lens is a full 50 mm and it offers a magnification of 4x. Its detection range is just under 360 feet and it has an integrated IR illuminator. Despite being just a Gen 1 device, this product comes with a tripod mount at its base. The Firefield 4 x 50 mm is also quite durable and can withstand a wide range of temperatures. Its images are clear thanks to its high resolution and it comes with a carrying case and a lens cloth.

GENERATIONS

Rather than select only one product for each generation, we have decided to show you a few of the options available. This will allow you to get a feel for what’s out there as well as see the differences and similarities in the various products.

BEST GEN 1 NIGHT VISION MONOCULAR

#1 Sightmark 4×50 Gen 1 Eclipse Night Vision

The Sightmark Eclipse also uses digital technology. However it still manages to provide quite a bit of night vision. It has the benefit of delivering current black and white images rather than the old standard of green and black images. Its objective is 5 mm and it offers a magnification of 4x. It comes with its own carrying case and a lens cover.

#2 Night Owl Xgen 2.1x Digital Night Vision

The Night Owl Xgen also uses digital technology to increase the power of this Gen 1 device. Its magnification is 2x and the IR illuminator helps to provide clear images. This device features 5 different settings that are controlled via a single button making it very easy to use in the field. Nevertheless, it does not offer all of the features found in our #1 product.

BEST GEN 2 NIGHT VISION MONOCULAR

#1 Night Optics D-300 Generation 2+ Standard Night Vision

This Night Optics product provides a slew of features. It has a multi-stage IR illuminator that is high power, low battery and infrared indicators, and optics that meet Mil spec standards. Its body is very durable and can withstand any type of weather. Its mounts allow users to attach it to anything from weapons to headgear and it comes with a hard carrying case.

#2 Armasight Avenger Gen 2+ ID Improved Definition

The Armasight Avenger gives users a magnification of 3x and has a resolution of 45 – 51 lpm. It offers automatic brightness controls and an automatic shut-off system. Its infrared illuminator is built-in and comes with a flood lens. The lens itself is 50 mm and provides a clear range of focus. This device is also water and fog resistant so that it can be used in a variety of weather scenarios. The Armasight Avenger can be used as a hand-held device or mounted on another object as needed. It is also compatible for use with a camera or video recorder. To make it a Gen 2+ product, it can be fitted with Gen 2+ image intensifier tubes using either Green Phosphor or Quick Silver.

#3 ATN Night Spirit-2 Gen 2+ Night Vision

The ATN Night Spirit is a strong Gen 2 product that has a magnification of 3x and a 50 mm lens that has been coated with Proshield for protection. Its field of view is 18 degrees and it comes with the extra features of automatic brightness control and bright light shut off. Its IR illuminator and battery both come with indicators for ease in use. This device is both camera and video recorder adaptable and can be operated via a single switch knob. It offers weather resistant construction and can operate from -40 to + 50 degrees Celsius. Its resolution is between 40 and 45 lpm providing clear images. Mounting options allow this product to be attached to head gear or a helmet.

BEST GEN 3 NIGHT VISION MONOCULAR

Armasight NYX-14 Alpha MGBy the time you get into the Gen 3 products, the price tag has soared through the roof. Be prepared to spend more than one thousand dollars to own a Gen 3 device. As stated, Gen 3 devices tend to be used mostly by law enforcement and the military. Nevertheless, they are available for civilian use in some cases. Consumers should note that some Gen 3 products come with restrictions in purchase.

#1 Armasight OPMOD PVS-14 Gen 3 Alpha Night Vision

The Armasight OPMOD offers an image intensifier tube with high performance manual gain. Its resolution is 64 -72 lpm and its lens provides a full 40 degrees of field of view. Its magnification is only 1x, but with such a powerful device more magnification is not really needed. This Gen 3 product comes with all of the automatic controls and indicators available as well as a built-in IR illuminator. It can operate in extreme temperatures from -51 to +49 Celsius. It is waterproof and meets the Mil Spec standard 810. Mounting options include helmet, head, weapons, tripod, camera and video recorder. It can also function as a hand-held device when needed.

#2 Armasight Nyx14-3-Alpha MG Gen 3 Multi-Purpose Night Vision

For those that wish for a Gen 3 with more magnification options, the Armasight Nyx14-3-Alpha MG offers a good product. It provides just as high a resolution (64-72 lpm) as our other recommended Gen 3 product, but it comes with the option to add 3x, 5x, and 8x magnification. Its lens is only 27 mm, but it offers a full 40 degrees in the field of view. Both the built-in IR illuminator and the battery come with indicators that show in the field of view. This product also has desired automatic features such brightness control, bright light and shut-off. It is waterproof and surpasses Mil Spec 810. This means that this product can be used in virtually any weather condition. Accessories provide options for mounting on various devices.

Binoculars

How to Clean Binoculars and their Lenses

Keeping your binoculars clean helps them last longer, and doing it properly ensures you have clear images.

The first thing you should do before cleaning your binoculars is look at the user manual. They often have recommendations for what tools to use or what chemicals to avoid on your lenses. Binocular lenses have different coatings, and manufacturers will know what chemicals harm the coating on your lenses.

After checking the user manual, there are four steps you can follow to clean your binoculars.

1: Brush dirt and dust off the lenses

One very important thing to remember is never rub dirt or dust off your lenses. Rubbing dirt off will cause microscopic scratches on your lenses. You won’t be able to see those scratches, but they scatter light. Over time that will add up to make your image cloudy. You may be tempted to use a soft microfiber cloth to clean the dust, but even that will rub the dust on the lens to create scratches.

Holding the binoculars upside down, use a lens cleaning pen with a soft brush or canned air from an office store to brush the dust off. If you use canned air, be sure to use short bursts of the air. The drastic temperature changes can cause damage to the lens. Don’t breathe or huff on your lens to remove dust. The water particles in your breath will spot your lens and possibly make it more dirty than before.

2: Use a cotton swab moistened with water or lens cleaning solution to wipe away any remaining grime.

Never use window or glasses cleaner on your binocular lenses. They contain chemicals that can damage the coating on your lenses. Don’t pour the lens cleaning solution directly on the lens. It can seep through the edges and cause damage inside the binoculars. If you have waterproof binoculars, you can run the lens directly under tap water. Be sure to use a light stream with less pressure. Remember to take care with damp binoculars. Don’t store them until they’re dry, and don’t put caps over damp lenses.

3: Use a soft, lent-free cotton cloth, microfiber cloth, or special lens tissue to wipe away smudges.

Never use a paper towel or face tissue. They’re made of woody particles that are too rough on your lens and will scratch it. Don’t use your shirt or other clothing you wear either. Those can be too rough or have dirt and dust on them. Make sure to store your cleaning cloth in a safe container where it won’t get dust or other substances on it.

Be gentle and don’t apply pressure when touching the lenses. You can put a little lens cleaner on the cloth if the smudge is still refusing to come off. Wipe in circular motions from the middle outward.

4: After you’ve cleaned your lenses, you can wipe down the body of your binoculars with a soft cloth to remove dirt or other grime. If you have removable eye cups, be sure to take them off to wipe them.

Don’t dismantle your binoculars when cleaning them. You may ruin the optic alignment. If there is something on the inside of your binoculars, take them to a professional.

Don’t touch your lenses with your fingers. Not only may your fingers be dirty, the natural oils on them could break down the coating on your lens.

Cleaning your binoculars is very important to keep them in good shape, but if you over-clean them, you may damage them. Only clean your lenses when there is something on them.

Digiscoping

Digiscoping Basics

Digiscoping is a photography technique that occurs when a camera and a spotting scope are used in tandem to capture long-distance pictures. This method involves placing the lens of a digital camera or smartphone to the eyepiece of a spotting scope in order to take pictures at a greater distance than the camera allows. It is especially popular among bird watchers and other nature enthusiasts because it allows for close up pictures to be taken without disturbing the animal. Digiscoping is also becoming popular with backyard astronomers to get photographs of the moon. Malaysian photographer Lawrence Poh pioneered the technique and is considered the father of digiscoping, while French birdwatcher Alain Fossè is credited with coining the term ‘digiscoping.’

The surge in popularity can be attributed to the fact that the equipment is generally inexpensive and the technique can be self-learned even by novice photographers. The coupling of the spotting scope and camera allows for distance photography to be possible without the necessity of long, heavy and often expensive telephoto lenses. It also allows users to use affordable cameras to achieve high-quality results. As a bonus, the gear needed is light-weight and easy to set up.

Equipment Needed

The basic equipment setup consists of a camera, a spotting scope, a tripod and of course a subject. The camera can either be a traditional point-and-click or can simply be the standard feature of a smartphone. When choosing a point-and-click camera, there are still a few features to consider for superior outcomes. Cameras with shorter lens extensions tend to perform better than models with longer lenses. Optical zooms should fall in x4 or x5. The camera should also have a good sensor and manually adjustable settings such as aperture and ISO. Keep in mind that the greater number of megapixels a camera has and the higher quality the optics, the better the pictures will be.

While most standard scopes can be used, those with high quality optical systems will produce the best results. Consider models with high definition optical and extra-low dispersions. The extra magnification used in digiscoping pulls in not only the object of the picture, it also pulls in small movements of the equipment caused by the photographer’s shaking or from the wind. This makes a quality tripod an important tool. The tripod should be designed to work with the spotting scope and should be sturdy. Weights can be used on the tripod to keep it balanced.

Once all the gear is in order all that is left is to find a subject to shoot. Gardens make a great starting point when learning the craft. Novices may find it helpful to start by shooting objects such as flowers or shrubbery first, then move on to animals once comfortable with the process.

The Technique

Digiscoping is achieved by connecting the camera lens to the spotting scope eyepiece. This can be done in a variety of ways. Smartphones can be held in place simply by placing a finger between the phone and the spotting scope eyepiece. This will help to keep the camera lens steady and at the correct distance from the eyepiece. This technique needs a steady hand. Users should also be careful of the alignment of the lenses and the distance between them in order to keep out shadows.

There are a few options with traditional point-and-click cameras. One possibility is to manually hold the camera lens up to the spotting scope eyepiece. Just like with a smartphone, this method takes a steady hand and a lot of practice to find the optimal distance between camera and scope. For those who have difficulty with this technique, there are adapters available that will connect the camera to the scope. These adapters come in both a universal model and in models specially made to work with the different cameras available. Those specifically designed to fit the camera being used will tend to work better and will result in higher quality pictures than those taken with a universal adapter. The most important thing to look at when choosing an adapter is whether or not the camera that will be mounted has a filter thread on the lens. Adapters for these types of cameras consist of a collar that attached to the spotting scope eyepiece and an adapter plate that screws onto the filter thread on the camera. If the camera does not have a filter thread or if using a camcorder, the adapter will still have the collar to attach to the spotting scope, but instead of an adapter plate, it will have a bracket designed to support the weight of the camera or camcorder. This plate can adjust to align the axis of both eyepieces at the appropriate location. After the camera and spotting scope are lined up, it’s time to snap away.

Tips and Tricks

The only way to perfect the art of digiscoping is to log hours of practice. Some will pick it up easily; others may need some time to master the techniques involved. Here are some tips and tricks to help make that practice useful.

  • When working with new equipment, pack the user’s manual with the rest of the gear. This way, if any questions arise about usage, the answer can be found while still out in the field.
  • Bring along extra batteries, power packs and memory cards. Phones and cameras tend to use battery life up quickly and the last thing a photographer wants is to run out of storage space when the perfect shot appears.
  • Remember that the shot does not need to be centered to be great. Consider placing the subject off to the side of the shot to allow for the inclusion of scenery.
  • When zooming in on a subject, leave the scope at the minimum zoom and zoom in using the camera. This will let in the most natural light.
  • Invest in good imaging software to edit pictures after they are taken. This allows for corrections with lighting and focus.
Misc

What is Field of View?

Field of view is the extent or the range of your visual area. In terms of optics, it is widest dimension an object is visible through the eyepiece of a scope or binocular. Binoculars are the most common form of optics purchased for sporting activities. It is important to choose the right features in a binocular for your activity. Field of view is an important factor when making that decision.

Field of view, or FOV, is expressed in two ways. It is either expressed as the width in feet at 1,000 yards or in degrees of field. When the field of view is expressed in feet, it is called the linear field of view. When it is shown in degrees, it is referred to as angular. It is simple to convert one measurement to the other. The linear field of view is measured in feet at 1,000 yards. One angular degree is equal to 52.5 feet. Once the angular field of view, or degrees, is known, multiply that figure by 52.5. In most cases, the field of view is often indicated in degrees on the outside of the binoculars. For example, if the angular field of view is six degrees, then multiply 6 by 52.5, for a total of 315 feet at 1,000 yards, or a linear field of view of 315 feet. Similarly, if the linear field of view is known, divide that number by 52.5 to obtain the angular field.

The term real field of view refers to angle of the visual field which can be seen without moving the binoculars. It is measured from a central point on the objective lens. A higher value will translate to a wider visual field. The term apparent field of view refers to the angle of the magnified view. A large apparent field of view will provide a wide field of view even at a higher magnification. Optics with a wide field of view will make it easier to follow moving objects.

Binoculars display two numbers. The first number, followed by an X, is the magnification. It is the degree by which an object will appear larger. Binoculars are manufactured in a range of magnification, but lower magnification binoculars, such as 5x to 8x, are the most popular and typically offer a wider field of view. Higher magnifications, 10x and above, are available for long distance viewing, but generally have a narrower field of view.

The second two-digit number is the aperture. This is the diameter of the objective lens measured in millimeters. The size of the objective lens determines the light gathering capability of the binocular. The greater the light gathering capability, the brighter an object will appear. However, the size of the objective lens will affect the physical size of the binocular. A larger lens diameter will mean a larger and heavier binocular.

The field of view, in addition to the magnification and aperture size, are important considerations when looking to purchase an optic. Binoculars with a wide field of view are popular for bird watching, wildlife watching, or sporting events, as it is easier to follow objects that move quickly. A general purpose binocular, such as 7×35 or 8×42, would be a good choice for these activities. Lightweight enough to carry hiking, these binoculars have a wide FOV yet are powerful enough to distinguish detail. However, if you intend to bird watch or wildlife watch near wet, marshy areas or in wet weather conditions, you may want to be sure that the binoculars you purchase are waterproof and nitrogen or argon purged for fog proofing.

In choosing binoculars for astronomy, the aperture will be an important specification. For this activity, a binocular such as 7×50 or 10×50 is preferred. The 10x magnification will aid in viewing the planets, but a larger aperture will be important in dim and low light conditions. A larger aperture and greater light gathering ability will provide better resolution and allow you to study the planets in better detail. Binoculars with magnifications of 16×70 or 20×80 will benefit from being mounted on a tripod for steady viewing.

For boating activities, the marine binocular traditionally purchased is the 7×50. The 7x magnification allows a wide field of view and makes steady viewing easier with the movement of the water. The 50mm lens offers color and detail when viewing the horizon. When choosing a binocular for hunting, a lower magnification, such as 7x or 8x, provides a wide field of view to scan fields and tree lines. A 42 or 50mm objective lens would be a good choice for low light conditions, as a hunter might expect game to be more active at dawn or nightfall.

Optics will open you to a variety of scenery and wildlife, but understanding the field of view and other features will aid in purchasing an optic that is right for you.

Night Vision

How Does Night Vision Work? The Technology Explained.

When people hear about night vision, modern image enhancement technology is what the majority of them think about. Image enhancement systems are actually commonly referred to as NVDs or night vision devices. These night vision devices rely heavily on a specialized image intensifier tube that collects both infrared and visible light before proceeding to amplify them. This is basically how it works, but it is a very brief description that does not go into the actual details of the process. The complete explanation is actually quite a bit more complicated.

Steps in the Night Vision Process

Although the introduction’s method of explaining night vision technology is technically correct, it is a very intricate process that requires a more detailed explanation. There are multiple steps in the process of creating an effective image enhancement system. This section will go over each of these steps separately with great attention to detail.

  1. For the first step in the night vision process, an objective lens is used for the capturing of ambient light and small amounts of near-infrared light.
  2. The light that has been gathered through the objective lens is transferred to the image intensifier tube. In the majority of night vision devices, the image intensifier tube usually has either two N-Cell or AA batteries. These act as power supplies for the tube to draw energy from for operation. The image intensifier tube outputs a relatively high voltage of somewhere around five thousand volts to the tube components.
  3. The image intensifier tube holds a photocathode for the purpose of converting the incoming photons into electrons.
  4. As the newly converted electrons are passing through the image intensifier tube, fairly similar electrons become released from atoms that exist in the tube. Through the use of a specialized microchannel plate that is located within the tube, this effectively multiplies the number of electrons by a factor of well over two thousand. This microchannel plate, or MCP, is a miniature disc built entirely out of glass. It has multiple millions of microscopic holes in it, which are also known as microchannels. These microchannels are constructed using an innovative fiber-optic technology. The plate is contained within a vacuum with small metal electrodes that reside on both sides of the disc. The microchannels in the plate are near forty-five times longer than they are wide, and they function by multiplying electrons.
  5. When the electrons coming out through the photocathode make contact with the first electrode of the microchannel plate, they are sped up into the microchannels. This is done by the five thousand volt pulses that are being sent between the two electrodes. Then the electrons begin passing through the microchannels in the plate. This causes the release of multiple thousands of separate electrons in either channel through a process that is called cascaded secondary emission. Basically, that is where the original electrons begin to collide with the channel’s side, exciting the atoms and causing more electrons to be released. The new electrons also begin to collide with other atoms, which creates a chain reaction. This results in thousands of the electrons exiting the channel where only a small amount had entered. When the microchannels in the plate are created, they are done so with a slight angle with about a five to eight-degree bias. This promotes electron collisions and reduces both the direct light and ion feedback from all of the phosphors located on the output side.
  6. For the next step, the electrons collide with a screen located at the end of the image intensifier tube. The screen is fully coated with phosphors, and the electrons lie still, maintaining their position in relation to the microchannel that they had passed through previously. This provides an almost perfect image due to the electrons maintaining the position of the original photons. The energy that the electrons contain causes the phosphors at the end of the tube to become excited and release a multitude of photons. These phosphors are what create the green coloring that currently characterizes night vision.
  7. The now green phosphor image can be viewed through a separate lens that is called the ocular lens. This other lens allows for the magnification and focusing of the image. The night vision device can now be connected to a monitor or other electronic display, or you can just look directly into the ocular lens.

That is basically how night vision goggles and scopes are capable of drawing in small amounts of light, and transforming and multiplying them until eventually using them to display a lighter, green image.

Various Applications

Night vision devices are truly innovative inventions, capable of letting the average person see many times better in the dark. They are widely used for various purposes, from sensitive military operations to late-night wildlife observation. Five common applications for night vision technology include:

  • Military operations
    Goggles, scopes, cameras, and other devices that utilize night vision technology are commonly employed for use in a variety of military operations.
  • Law enforcement
    Certain law enforcement agencies use a number of night vision devices to increase efficiency in many different circumstances.
  • Observation of wildlife
    Night vision goggles and cameras are ideal for observing local wildlife and their behaviors after the sun sets.
  • Advanced security
    Different types of night vision cameras are commonly used for the security of properties.
  • Surveillance
    Goggles with night vision capability can be used to perform surveillance or search and rescue operations in the dead of night.

Conclusion

Night vision is an innovative technology that is capable of being utilized in numerous situations. A complicated process allows for small amounts of light to be converted into full-scale images that increase the user’s visibility in dark environments. Employing night vision technology can potentially enhance efficiency during the night in various ways, allowing the user to examine their nearby surroundings with significantly improved vision and awareness.

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