Night vision - what to look for

This guide is meant to help you think about what you want from your night vision experience. Night vision has many uses beyond the military applications. Birders and nature lovers have learnedto gaze in wonder at the lively displays of night creatures.They are also an aid in hunting - certain animals only gee out at night. Night fisherman have used these devices see to fishin shallowwater. Neighborhood watch captains have successfullyidentified criminals.What do you want to use your device for?I hope to help guide you to the correct type of device for your needs.
When looking for a night vision device - whether it is a scope, a binocular or monocular, the most important thing to think about is your intended use. Consider your environment carefully - "one size" does not fit all! A scope meant for a hunter - who works in the darkest woods - will practically blind a person using their scope for neighborhood watch in an average urban nightscape. Too much light entering the lens can also destroy the unit, you can't use these things in the daytime or in substantial brightness.

Another consideration of your environment is distance - think about how far away you might typically be from the things you intend to observe. keep in mind that the amount of light captured relates directly to your magnification. A powerful lens will give you higher magnification for viewing far off objects, but it also decreases the amount of light captured.
The factors typically involved in choosing a night vision device are:
Gain: this is related to the light you can recieve. If you have a higher magnification you need to have a higher gain, because long lenses do not transfer light well. A typical lens with good gain is 23 lin./mm and up, but do keep in mind that high gain is not a good thing in wel lit places. High gain is less needed when viewing objects up close. In other words, you dont need high gain when viewing the deer in your suburban backyard.
Range: this is related to your level of magnification - 1x to 3x is typical. 2x or better is what I regemend, but again, look at how that affects your gain.
Image quality: this is related to the resolution of your device - it's just like a little television set - higher resolution is always good.
Speaking of image quality - just what does night vison look like? Image enhancement has to do with gathering available light and boosting it to a level that the human eye can easily see. It looks a bit like a cheap black and white television, tinted green. Thermal or "heat vision" is wonderfully and weirdly colored, but it's a type of night vision not typically available for the consumer, so we're looking at the average image enhancement device experience. Through an image-enhancement type of night scope you should expect to see clearly and crisply in the center of your vision, with increasing blur to the sides. The cheaper and earlier types of device will have increased distortion and possibly black spots. The images you see will be a glowing green - because the devices basically "sees" in shades of grey, and the human eye can most easily discern between shades of green. Every living creatures will have spooky glowing eyes. This isn't so good for documenting yourprom - nobody will thank you for showing them in this eerie light. On the bright side, you can aim it at your friends to make them look like zombies!
Night vision devices gee in several "generations". First generation units can be used in full or mostly full moonlight. Second generation scopes use a different technology, featuring "microchannel plates" that have been charged with electrons. It's inner workings are quite geplicated, but you dont need to know how it works to enjoy the increased clarity. Second generation scopes can be used during full to thin moon phases, and can typically see much farther than first generation. Third generation scopes can be used in starlight and even cloudy nights. This is the stuff the American military uses, and they dont like it when 3rd or even 2nd generation is shipped out of the USA, so be aware they may pay attention evento what you order on okay!
Most of the affordable night vision scopes are first generation. For first generation scopes, it is useful to have an infrared or "IR" light mounted to your scope. This is useful because it gives off a little more light for your scope to work with, and the infrared light cannot be seen with the naked eye. The later or higher generation scopes dont typically use IR illumination, although many users have found it can be a bonus. By the way, I have seen the "night vision" devices that consist of a cheap plastic monocular attached to a normal flashlight - this would entertain a five year old, but most likely scare away whatever or whoever you have in your sights!
As to the style of these devices - it's up to you what you like to play or work with. they can be cameras, monoculars ( spyglasses ), binoculars, or even goggles. I prefer monoculars, because I find them lighter and I dont mind squinting one eye. Binoculars give a better view because they have depth perception. Cameras are good for recording what you see. With an infrared light on a night vision camera, you can easily spot and document a license plate on a suspect car at night. Goggles are fun because they are hands-free and they are great for wandering in the forest at night. Goggles typically dont magnify well, though you can sometimes add lenses to them.
No matter what your intended use, I hope this guide has shed a little light on your quest for night vision!