Table of Contents
How Night Vision Works - General Description
Imagine standing outside after dusk and being able to hone in on an animal in pitch darkness. Archery, fishing, and hunting are now 24 hour sports. How is night vision different from our line of daytime binoculars? Night Vision devices are given thier designation due to the presence of an image intensifier tube.
Image intensification. Night vision is made possible by using an image intensification tube to amplify very small quantities of light. Image intensification is also known as gain multiplication.
Light enters a night vision product through an objective lens and strikes a photo cathode that has a high-energy charge from the power supply. The energy charge accelerates across a vacuum inside the intensifier and strikes a phosphor screen (like a TV screen) where the image is focused. The eyepiece magnifies the image.
Night vision devices have various image magnifications. The distance at which a human-sized figure can be clearly recognized under normal conditions (moon and starlight) depends on both the magnifying power of the objective lens and the strength of the image intensifier. There are distance limitations in observing objects in darkness through a night vision device. Most Generation 1 devices are able to provide the user with up to 350 yards of viewing capability, while Generation 2 and Generation 3 devices can provide the user with up to 500 yards of viewing distance.
A Night Vision phosphor screen is purposefully colored green because the human eye can differentiate more shades of green than other phosphor colors.
Image intensifier tubes.
An image intensifier is a vacuum-tube that illuminates users’ view through a process of converting photons into electrons.
A simple explanation of the image intensification process in a night vision device.
The objective lens captures ambient light. The gathered light passes through to the image tube to a photocathode, which converts the photons into electrons. As the converted electrons pass through the tube, similar electronics are also released creating a multiplier of electrons (usually 900) through the micro channel plate.
On the other side of the image tube, electronics hit a phosphor coated screen producing the image that the user views through the objective lenses. The green phosphor image is viewed through the ocular lenses, which are used to focus onto the viewed images. Due to the energy of the charged electrons, some night vision devices may cause a slight high-pitched whine, which is normal in Generation 1 night vision devices.
Nearly all Generation 1 night vision devices use image tubes produces by the publicly traded company “JSC Ekran” of Novosibirsk Russia.
Most Generation 2 and Generation 3 night vision devices made by Litton and ITT are produced in the United States.
Generations
Grades, or quality levels of night vision devices are normally categorized by “Generations”. Each Generation night vision device uses a different grade image intensifier tube and more sophisticated engineering technology
Generation 0. The first night vision devices produced during World War II were categorized as Generation 0 due to their use of active infrared. In active infrared night vision devices, IR illuminators emit a beam (akin to a flashlight) of infrared light which bounced back to the night vision device to create illuminated images. One major drawback of active infrared night vision devices used during the middle of the 20th century was the ability for hostile forces to see the bright red images being emitted from the devices.
Generation 1. Generation 1 night vision, which is widely used by end users and professionals, use passive infrared technology. Generation 1 night vision image tubes gather available ambient light (from stars, moon, streetlights) and amplify them as described above. Generation 1 night vision devices must use infrared illuminators if no ambient light is present. Night Vision Optics Dot Comrecommends high end Generation 1 night vision devices due to their best overall value, as determined by their premium performance and affordability .
Major suppliers of High-End Generation 1 night vision devices include Rigel Optics and Night Owl Optics. These suppliers are known for thier very light-weight night vision devices, and bright green images.
Major suppliers of mid-range Generation 1 night vision devices include Newcon Optik, and Yukon .
Low end night vision devices, which consumers should exercise caution with when buying include manufacturers such as Baigish, ROMZ, and Lytkarino, all based in Russia.
Generation 2. Generation 2 night vision is often referred to as military grade or mil-spec night vision. While substantially more expensive than Generation 1, Generation 2 provides the user with better image resolution, and brighter green images through the phosphor screen. Due to the presence of a high-performance micro channel plate (MCP), it is possible to view objects in very low light conditions, without the aid of an infrared illuminator. In addition to accelerating electronics, the micro channel plate increases the total number of electronics in the vacuum tube. Major suppliers of Generation 2 night vision include ATN, US Night Vision, and Night Optics USA.
Generation 3. Generation 3 night vision are an extension of the technology used in Generation 2 night vision (MCP), but provide the user with the highest possible image resolution and brightness. Generation 3 night vision devices use gallium arsenide, which has a very high saturated electronic velocity, which is extremely efficient at converting photons to electrons. Major suppliers of Generation 3 night vision include ITT and Litton.
Current Phase of the Moon
in Real-Time
Automatic Brightness Control
An electronic feature that automatically reduces voltages to the microchannel plate to keep the image intensifier's brightness within optimal limits and protect the tube. The effect of this can be seen when rapidly changing from low-light to high-light conditions; the image gets brighter and then, after a momentary delay, suddenly dims to a constant level.
Black Spots
Usually cosmetic blemishes in the image which are inherent in the production process. In other cases, as dirt builds on the lens, black spots are also visible. Black spots resulting from the production process neither influence the image quality nor interfere with night observation. Spots which form due to dirt should be removed carefully with a soft cloth.
Bright-Source Protection
An electronic function that reduces the voltage to the photocathode when the night vision device is exposed to bright light sources such as room lights or car lights. BSP protects the image tube from damage and enhances its life; however, it also has the effect of lowering resolution when functioning.
Diopter
The unit of measure used to define eye correction or the refractive power of a lens. In most cases, an optical eyepiece will accommodate for differences in individual eyesight among users.
Electro-optical transducer
Primary system which directs and accelerates the photoelectronic flux taking into account the potential difference between the photocathode and the screen, and forms the electronic image.
Emission Point
A pinpoint of bright light in the image area that does not vanish when all light is blocked from the objective lens.
Eye Relief
The distance your eyes must be from the farthest element of an eyepiece in order to achieve the optimal image area.
Gain
Sometimes referred to as brightness gain. Gain is the number of times a night vision device amplifies light input. For a detailed description of gain and how it can affect performance, please refer to our “First Time Buyer Section”.
Infrared
Light radiated with wavelengths longer than those of red light.
Line Pairs per Millimeter (lp/mm)
Units used to measure image intensifier resolution.
Lumen
The unit denoting the photons perceivable by the human eye per one second.
Photosensitivity
The ability of the photocathode material to produce an electrical response when subjected to photons.
Recticle
The “neon colored” round aiming device found in many night vision rifle scopes which serves as cross-hairs.
Resolution
The ability of an image intensifier or night vision system to distinguish between objects close together. Image intensifier resolution is measured in line pairs per millimeter (lp/mm). For a detailed description of resolution and how it can affect performance, please refer to our “First Time Buyer Section”.
Frequently Asked Questions
1. How does night vision technology work?
Night Vision scopes and binoculars are electro-optical devices that intensify (or amplify) existing light instead of relying on a light source of their own. The devices are sensitive to a broad spectrum of light, from visible through infrared. An accessory illuminator can increase the light available at the infrared end of the spectrum by casting a beam of light that is not visible to the human eye.
You do not look "through" a Night Vision product, you look at the amplified electronic image on a phosphor screen.
Light enters the Night Vision product through an objective lens and strikes a photo cathode that has a high-energy charge from the power supply. The energy charge accelerates across a vacuum inside the intensifier and strikes a phosphor screen (like a TV screen) where the image is focused. The eyepiece magnifies the image.
2. Why are the projected images always green using night vision technology?
A Night Vision phosphor screen is purposefully colored green because the human eye can differentiate more shades of green than other phosphor colors.
3. What is the main difference between Russian made and US made Night Vision Equipment?
The large majority of Gen. 1 and Gen. 1+ night vision products sold in the US are of Russian origin, packaged and branded locally, usually by large optical manufacturers. The United States produces primarily Gen 2 and Gen 3 night vision technology, which is employed by and large by the military and other governmental organizations, and far out of the reach of most consumers’ budget. Russia is the largest producer of Gen 1 and Gen 1+ image intensifiers in the world. Russian made night vision equipment, which also owes its origins to the Defense Industry, has always enjoyed a reputation of being among the best quality in the world.
4. What is the effective viewing range of Night Vision Device?
It varies anywhere from 30 to 300 meters [900 feet]. The maximum viewing distance depends on the conditions of use. Overcast conditions, fog, rain etc. may reduce the effective distance of a night vision viewer. An Infrared illuminator will increase your viewing range, especially in enclosed spaces like a warehouse, garage or other enclosed parameters.
5. Can I use a Night Vision device in extremely low light, or absolutely no light conditions?
Yes. While it is true that your Night Vision device needs some available light to work, it is still possible to see a bright image in low light or no light conditions with the use of an Infrared Illuminator, which can be either built-in or attached to the device. On most of the www.nightvisionoptics.com product line, the Infrared Illuminator is either standard, or available as an option.
6. Which Night Vision Optics Dot Com product would you recommend for a first-time leisure user?
Our Rigel 1100 Pro Night Vision Monocular is affordable and offer many features.
7. What type of light source can be harmful to a Night Vision Device?
Your night vision device is designed to be used to assist your viewing in the dark. It may be harmful and will likely damage the device if you use it during the daytime or whenever there is sufficient light to see the object. Also keep in mind that strong direct light, such as projectors, car headlamps, strong flashlights and so on, may be harmful to your night vision unit if you direct you device at the source of these intense lights.
8. Can a Night Vision device and/or Infrared Illuminator be harmful to an individual?
All our night vision products, inclusive of our Rigel Optics product line comply with FDA and international regulations in terms of safety for an electronic device, similar to other electronic devices such as televisions, and radios. Individuals with sensitive eyes such as those who experience eye fatigue while watching television, may experience the same sort of fatigue if they use their night vision viewer for a prolonged time. Infrared illuminators are generally low power devices, which do not cause harm to humans when making eye contact with them.
9. Are Night Vision Optics Dot Com products waterproof?
In general no. Exposure to water and other liquids and even high humidity may damage night vision devices that are not specifically protected against these elements. However, we do offer one specialty product, the Rigel 1150 Marine Night Vision Monocular which is waterproof and can sustain substantial exposures to water. All our models are weather resistant, which means they can withstand short exposure to light rain or high humidity conditions.
10. Do you ship internationally?
No.
11. What type of batteries do Night Vision Optics Dot Com devices use, and how long will they last?
Night Vision Optics Dot Com and Rigel Optics devices use commonly available batteries, such as 1,5V AA type, 9Volt square type, or 3V Lithium type. Generally the device will last up to 20-40 hours of continuous use if the Infrared Illuminator is in OFF position. If used with the IR Illuminator, expect 30-40% less operating time.
12. Does a high magnification device lend itself to better night vision viewing?
Not always. While a high magnification device can in a lot of cases will increase the viewing distance, image gain and resolution are key factors to quality viewing. If a night vision binocular has a high magnification, of 7 times for example, but a low resolution and image gain, then the object viewed from a far off distance will be cloudy and dark. It is best to choose a night vision device with a good combination of high image gain, high resolution [23 lin./mm and up] and good magnification [2.0 or better].
13. What is the warranty-coverage on Night Vision Optics Dot Com Products?
Every Night Vision Optics Dot Com and Rigel Optics device comes with a 12-month US warranty on parts and labor. For additional questions, consult your owner's manual. We will also service your device after the warranty period.
14. Is it really safe to purchase online using my credit card?
Yes. Our secure server software (SSL) is the industry standard and the best software available today for secure e-commerce transactions. It encrypts all of your personal information, including credit card number, name, and address, so that it cannot be read as the information travels over the Internet.
If you still have questions, or would like further information, please feel free to contact our customer care department directly or by telephone in the United States toll-free at 866-810-3398. We will be happy to assist you.
Product User Manuals and Troubleshooting
If you have purchased a product from Night Vision Optics Dot Com and have misplaced or lost your user manual, contact us.
and we will be happy to send you a new copy. Always make sure that you closely follow the guidelines for use, as all our products are sophisticated electro-optical devices. Further, if you are experiencing glitches with your product, contact us and we will send you a brief troubleshooting guide.
Trouble Shooting
Possible glitches and common troubleshooting methods
| Glitch |
Likely Reason |
Solution |
| Image is not appearing |
Batteries are dead |
Insert new batteries |
| Image is not appearing |
Contact has been cut off between the batteries and the connection points |
Restore the poor contacts |
| Image is not appearing |
Lens cap is still on |
Remove lens cap [provided the natural environment is dark] |
| Projected image is dim |
Battery current is low |
Insert new batteries |
| Projected image is dim |
Natural illumination level is low |
Switch on the IR illuminator |
| Projected image is cloudy |
Objective lens is dirty |
Clean objective lens with very fine cloth soaked in alcohol |
| Projected image is cloudy |
Focus is distorted |
Focus in on object, or if too close to the object, move back |
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