|
||||
|
FAQ - Night Vision
Equipment After the sun goes down and light-loving insects and animals go to bed, a whole new variety of living creatures are just having their morning cup of coffee. Have you ever wished that you could see what went on in the woods or your own backyard after dark? Or do you work or boat at night, and need some help to see possible hazards before they come upon you? Well, wait no more! Night vision used to be so expensive or limited in what civilians were allowed to possess that very few individuals could afford to have light-amplifying equipment, but that is no longer the case. Let's talk about how night vision equipment works, and in what ways it can be used to enhance your enjoyment or safety during the evening hours. All Night Vision equipment, whether binoculars or scopes, are electro-optical devices that amplify the existing light it encounters. You will find the terms "Generation I", "Generation II", and "Generation III" used quite frequently in regards to specifications in any night vision equipment you are interested in. Let me explain each briefly, as this is probably the most important information you can have at your fingertips to decide between models: TOP Types of N.V. Equipment Generation I: The U.S. evolution of technology in night vision equipment has gone through three stages, or generations. Generation I was developed in the 1960's and the devices were large and bulky. They needed full moonlight to amplify an image about 1,000 times and even then, were not real reliable performers. Both Generation I and Generation II only amplify the light that is visible to the human eye. The intensifier tube (the most expensive part of the equipment) generally had an operating life of about 2,000 hours, and would then need to be replaced. Of course, in the 60's, this was innovative, cool technology, but we've come along way since then. Generation II: In the early 70's, the development of the Microchannel Plate led to night vision devices that had much better light gain but in a smaller, more compact package. Instead of amplifying ambient light 1000x, Generation II technology intensifies the light source up to 20,000 times and it's operating life jumped to anywhere between 2,500 and 4,000 hours. Finally, instead of needing a full moon (or equivalent light source) to work with any reliability (as Generation I technology needed), Generation II can operate on quarter moon lighting. Quite a jump forward, but today the state of the art technology is... Generation III: This is the newest technology, developed in the 80's. First of all, the light gain on these newer units is much higher, anywhere from 30,000 to 50,000 times! While Gen I and Gen II devices could only amplify light that is visible to the human eye, Gen III equipment is sensitive to near-infrared light, or the 600-900 nanometer region, a wavelength that the night sky has an abundance of. Even very low levels of starlight is enough for Gen III intensifiers to work off of. They can see three times further and offer three times more visual acuity than Gen II units. Because of Gen III's high infrared response, natural backgrounds are much easier to see. For instance, water has a very low reflectance in infrared, but objects like wood and vegetation respond well. This means that you will be able to detect hazards in the water if you are boating at night to a much greater degree with a Generation III device. TOP FAQ's How does Night Vision equipment work? Light, in the form of starlight, moonlight, street lights, etc., enters the front objective lens of the device and strikes a charged photo cathode, which in turn emits photoelectric energy. This energy is accelerated by an electric or magnetic field to a much higher intensity. It then strikes a phosphor screen (like a television screen) where the image is focused. One then looks through the eyepiece of the device to magnify the image. The reason the screen is green is because the human eye can see more shades of green than any of the other phosphor colors. How far can I see with night vision equipment? Most devices come standard with very little magnification built into them, usually anywhere from 1x to 4x. The lower the magnification, the wider the field of view will generally be. Many systems have optional lenses available that will attach to the main unit, allowing for higher magnification. The distance that various units can "see" to are dependent upon the the magnification range, but also upon the clarity of any given night. Anywhere from 150 yards to 400 yards is most common, but some units have magnification ranges high enough to see over 1,000 yards away, again, depending on seeing conditions. Can I use night vision for photography and video? You can find units that will attach to a SLR or video camera, but not all units will accommodate attachments, so make sure that the device you choose is capable of mounting adapters, lenses, etc. to them if you desire to record at night. Also check to make sure that adapters are readily available. Of course, the use of a tripod will be important to assure the most clear picture possible. TOP |
||||
|
