NIGHT VISION TECHNOLOGY

MISSION OFTHE NIGHT VISION DEVICE
MISSION OF THE NIGHT VISION DEVICE
For a printable "About Night Vision" Data Sheet, please click here.

•  To allow the user to see more clearly, further and with more detail in low light and dark environments.

•  To enhance ambient light in low light situations.

•  To utilize built–in Infrared Light in completely dark environments, allowing you to see even in total darkness!

NIGHT VISION TECHNOLOGY
For a printable "About Night Vision" Data Sheet, please click here.

•  Each unit contains an Objective Lens, an Electronic Intensifier Tube with the high voltage power supply and the Ocular (Eyepiece).

•  Available (Ambient) light reflects from the viewed object, passes through the Objective Lens and creates an image of that object on the photo cathode screen, located on the front of the Electronic Intensifier Tube.

•  Inside the tube, the light is electronically amplified and projected in a green glow on a phosphorescent screen, located on the back of the tube. Then the illuminated image is picked up by the Ocular and brought to the eye.

•  The built-in Infrared illuminator emits I nfrared light, which reflects from the viewed object and is then amplified by the tube the same way as ambient light. Infrared illuminator is used in complete darkness, or whenever there is not enough ambient light to see clearly.

• Optical part of every Night Vision device consists of the Objective Lens and the Ocular (Eyepiece).

•  The main demand for an Objective Lens is the high light transmittance in the visible and near Infrared light. It is expressed with the geometric light power from the line (F-number). Examples of the F-numbers are 1.0, 1.4, 2.0, 2.8 etc… The higher the F-number is, the less light is transmitted through the objective lens. Good light transmittance is very important for any night vision device, but especially for Generation-I models.

•  The Ocular is equally important for any night vision device, as it picks up the illuminated image from the Intensifier tube and brings it to the user's eye. All of the Luna units feature high quality all-glass oculars with anywhere between 4 and 21 lens elements to provide the highest possible image quality to the user.

•  IMPORTANT: The magnification of the night vision devices is generally much lower than of the daylight binoculars or spotting scopes. It is important to consider the fact that when employing higher magnification, the objective lens elements are thicker and therefore transmitting less light than thinner lens. The magnification of Luna devices ranges from 1x to 7x, preserving the best possible balance between image magnification and the light transmission.

•  The two most important characteristics for the Night Vision are the characteristics of the Intensifier Tube and the Optics of the unit.

•  Internationally accepted terminology classifies the Intensifier Tubes as Generation-I, II, III, with intermediate levels of Generation-I+ and II+.

•  Generation-I night vision is the most popular among the general consumer due to its relative low cost and affordability. Every Generation-I device employs a vacuum tube with the photo cathode sensitivity of 120-280 microamperes per lumen. The light amplification of these tubes is 120-900 times the ambient light. Resolution in the center of the image is 20-38 line-pairs per millimeter. One of the specific characteristics of generation-I units is that the image is most clear in the center of the field of view, while becoming somewhat distorted and less clear at the edges. NOTE: Even within Generation-I, tubes may be quite different in their performance. During the manufacturing process all tubes are evaluated and graded according to their quality and performance and are sold at significantly different prices depending on their light amplification and image clarity. This of course is reflected in the final price of the Night Vision device. Luna Optics is only buying the top grades of the intensifier tubes, thus our models tend to be pricier than most of our competition. Additionally, as a part of our quality control, every Luna unit is inspected twice: once at the factory level and once again at our US warehouse prior to the shipment.

•  Generation-I+ tube is a further improvement of the Generation-I tube with a fiber optic plate installed at the front or the back of the tube. This allows for a dramatic improvement of the image resolution and it prevents distortion especially at the edges. Such tube has a light amplification of 900-1,000 times and the sensitivity increases to nearly 300 microamperes per lumen. Resolution in the center is 50 line-pairs per millimeter. NOTE: Many of our competitors use designation I+ to describe their regular Generation-I devices to mislead their buyers and make them believe they are buying a Generation-I+ product. A true Generation-I+ device costs as much as the low-grade Generation-II product and the current Generation-I+ tube production is very limited and therefore increases the cost of such units even more.

•  Generation-II tube differs from generation-I and I+ by employing a special electron amplifier – the Micro Channel Plate (MCP). The performance characteristics of such tube is much greater light amplification of 20,000 times the ambient light; increased sensitivity of 300-320 microamperes per lumen and increased lifetime of the tube (4,000-5,000 hours, compared to 2,000-2,500 hours of Generation-I and I+). Two types of the intensifier tubes with MCP are available: the 25mm and 18mm. From the user prospective, the larger the diameter, the more efficient the tube is, however it would also require a larger night vision unit when assembled.

•  Generation-II+ tube is an improvement of Generation-II tube with the light amplification of 22,000-25,000 times and sensitivity of 300-600 microamperes per lumen (please note that all Gen-2+ tubes are Russian-made, as the US technology switched from Gen-2 to Gen-3, bypassing the Gen-2+. Today due to the Russian legislature, the maximum sensitivity allowed for Export outside of Russia is 350 microamperes per lumen). Resolution in the center is 39-50 line-pairs per millimeter. Lifetime is 5,000 hours. Generation-II+ units are equipped with automatic gain control, which regulates the brightness of the image depending on the outside light condition. The units also have a flash protection and virtually distortion free image even at the edges. Until recently, such units were used by Military, but now they become more widely available. NOTE: Export outside of the US of any Generation-II and II+ model is controlled by the US Department of Commerce and must be approved by submitting an End-User Certificate.

•  Generation-III tube differs from Generation II+ by use of the photo cathode based on Gallium Arsenate with even greater sensitivity, especially in the IR spectrum (900-1600 microamperes per lumen), center resolution of 50-64 line-pairs per millimeter and an expected tube life of 10,000 hours. Such tubes are utilized in the military night vision and the commercial availability is limited and mostly left to the tubes, which did not pass the military specifications during the initial testing, or to the used (refurbished) tubes. NOTE: Export outside of the US of any Generation-III model is controlled by the US Department of State and the Export License is needed.