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MENGENAL DIGITAL NIGHT VISION

Digital Night Vision-The New Way To See In The Dark

Digital night vision is the latest and greatest in night vision evolution. Recent improvements in CCD and CMOS sensor technology have resulted in much better near infrared light capture. The displays, near infrared illuminators and image interpreting software that feed the displays have also been improved and optimized for night vision.

There are now digital night vision monoculars on the market with light gathering and image quality comparable to Gen 2 at Gen 1 night vision prices.


The medium to long range performance of these digital monoculars is impressive..

Some big advantages of digital night vision devices:

Day and night use: Image intensifiers are useless in bright light and especially daylight.   The image intensifiers in most of the night vision available to the general public are destroyed or at least badly damaged by bright light. Digital night vision devices work as well as any camcorder in the daylight and produce clear bright images in near dark conditions. Digital night vision devices handle the transitions between night and day without image interruptions or equipment damage.

Instead of the round green image of the image intensifier tube you are presented with a clear black and white image on a rectangular screen. With some models you even have a choice of display colors and even color vision. The images are as clear on the edge of the image as they are at the center.

Both of the digital night vision devices mentioned above allow direct video output for digital recording or viewing on an auxiliary monitor. Image intensifiers require camera adapters.

Digital night vision technology is the night vision of the future. Just like the old cathode ray tube televisions, the image tubes used in night vision devices may all be replaced by CCD and CMOS sensors in time.

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1. What is a Night Vision Devices (NVD)?

2.Why use a Night Visions Devices Instead of a Flashlight?

Two reasons: 1) Night Visions Devices make possible a quality of seeing that is far superior to flashlights.  They provide your eyes with a light amplification tool that gives you much more night vision sensitivity than many nocturnal animals. 2) See, without being seen.  Think of the advantages of seeing without intruding when you are trying to find your way around an unlit campground.  Property owners can observe nocturnal criminal activity.  Hunters and nature lovers can observe animals without startling them.  If you suspect a prowler is nearby, you can spot the “perpetrator†without alarming him and safely call the police.

3. What is the Minimal Amount of Light Required to Operate an NVD?

The threshold of vision with an NVD can vary with different generations,with the quality of the devices, distance and the environment.  A Generation-1 Night vision with 500x amplification will give a very useful image in the dimmest light of a scarcely visible new moon.  From 100 feet, you can distinguish between kinds of animals, whether a human figure is familiar, male or female.  While the screen images are not as sharp as a photograph, Night Visions Devices are astonishing in what they accomplish.  System amplification of most second-generation Night Visions Devices is around 22,000 times!

Even on a moonless night or in a dark interior, everything within range of the IR illuminator.

Science and Tech — January 26, 2012 7:59 am

Did You Know: How does night vision work?

Question: How does night vision work?

Answer: An image intensifier tube amplifies light on the lower end of the infrared light spectrum to illuminate images.

Invisible waves
Objects detectable by the unaided eye typically reflect light on the visible light spectrum. In the dark, these objects only reflect light on the infrared spectrum, the range of wavelengths just below visible light, making them imperceptible to observers.

Light is emitted in the form of photons, packets of energy released when excited electrons return to their normal ground state. Image enhancement employs this principle to intensify infrared light by converting photons to electrons and back again.

Intense illumination
In night vision gear, an optical lens gathers infrared light and sends it into an image intensifier tube, where light energy is converted into electrons. These pass through a microchannel plate, causing a chain reaction that releases thousands of others.

At the end of the tube, the electrons hit a screen coated with compounds called phosphors. These electrons maintain their position relative to the channel through which they passed to provide a perfect replica of the image. The energy of the electrons causes the phosphors to reach an excited state and release photons, creating the characteristic green image of night vision.

GEN 1  AND GEN2

Generation 1 -
The next generation of NVDs moved away from active infrared, using passive infrared instead.
 
Once dubbed Starlight by the U.S. Army, these NVDs use ambient light provided by the moon and stars to augment the normal amounts of reflected infrared in the environment.
This means that they did not require a source of projected infrared light. This also means that they do not work very well on cloudy or moonless nights.
Generation-1 NVDs use the same image-intensifier tube technology as Generation 0, with both cathode and anode, so image distortion and short tube life are still a problem.
 
Generation 2 -
Major improvements in image-intensifier tubes resulted in Generation-2 NVDs. They offer improved resolution and performance over Generation-1 devices, and are considerably more reliable.
 
The biggest gain in Generation 2 is the ability to see in extremely low light conditions, such as a moonless night.
 
This increased sensitivity is due to the addition of the microchannel plate to the image-intensifier tube.
 
Since the MCP actually increases the number of electrons instead of just accelerating the original ones, the images are significantly less distorted and brighter than earlier-generation NVDs.