Night Vision Use and Care

Using Night Vision

Whether for fishing, camping, or nature watching, night vision has made significant advances and has become affordable to the general consumer. Their uses stretch far beyond the confines of this article. The major intended application for consumers will determine what type of device is best and what quality is needed.

Low cost Generation 1 devices are fine for nighttime applications like finding the keys you dropped while setting up camp in the dark, dealing with tackle while night fishing, or light nature behavior observation. These will work to find birds and animals at night but their range is low and seeing details for identification might be only possible in the closest encounters. As mentioned earlier, Generation 1 devices vary significantly in quality and very low cost products can disappoint beginning users. Choosing well made units is extremely important for consumers who do not just want a new toy that will eventually end up in the closet.
For more advanced nighttime observations, Generations 2 and 3 night vision instruments are worth their added cost and open much greater possibilities. The extended range, greater light amplification, sharper image, and lesser edge distortions open up the view and possibilities both for finding nature and seeing details for identification.

Many consumers are learning about this technology as the devices become more affordable. Night vision devices are becoming very popular because they open the nighttime world to see what has always been hidden in a cloak of darkness. They are very different from daytime optics and take some time to learn how to use effectively. It is a bit like using a pair of binoculars for the first time. There is a period of time needed to learn how to find things in the view and focus on them quickly. Night vision devices take practice to master all the advantages they offer.

In the case of nature observation, which is our main consideration with these devices, there are many animals and birds that only become active at night and a good night vision device can be an invaluable tool. Not only are there many critters and birds that are primarily nocturnal (active at night), many of the diurnal (primarily active in the daytime) animals and birds will allow much closer approaches from observers in the dark.

Ducks and water birds will let you approach much closer at night and are just generally cautious of you while using night vision but try turning on a light and they will be in flight in short order. Eye shine can be a real help in finding birds and other animals at night. It is true that the IR illuminator will make the eyes of owls and other night creatures really shine and stick out. Forests to oceans and camping to boating, night vision opens new exciting frontiers for seeing in the night that has never been possible or affordable before.

Controls and adjustments

Getting a new device these days usually involves a period of learning to use the controls and becoming proficient with them. If you are accustomed to using daytime optics, there are also some things you have to unlearn. In general, night vision devices have three controls: the on/off switch (or switches), the eyepiece focus, and the front lens focus.

Some night vision devices have separate switches for the main power and the IR illuminator, while others have one switch that cycles from off to main power on, then both main power and IR illuminator on, and finally back to off. These switches also control two indicator lights: a green LED for main power and a red LED for the IR illuminator. It is important to be aware of these LEDs, as the IR illuminator beam is not visible to the unaided eye, and leaving it on could drain the batteries unnecessarily. Some models also have IR illuminator controls for adjusting from wide field illumination to narrow beam.

Focusing night vision devices is a two-step process. First, focus the eyepiece. The easiest way is to set the eyepiece in lit environment without removing the Protective Lens Cap. It does not matter if the objective lens is in perfect focus to be able to tell when you have the best focus for the eyepiece - just find where the image is the sharpest. Once set, this focus should not change for a given individual as the distance from the eyepiece to the phosphorescent screen is fixed. Some units, however, have very loose focus rings. For these, a small piece of electrical tape will keep the focus ring in place.

Once the eyepiece is set only the objective lens will need to be adjusted to focus on different areas or objects being observed.

A fourth control available on some night vision devices is an aperture ring. Similar to the f-stop of a camera lens, this ring controls the amount of light entering the device. This is a very useful adjustment for dimming or brightening the display to get a comfortably lighted view.

Extending the capabilities of night vision and add-ons

Accessories and add-ons include:

1. AC power adapters.
2. Demist shields that snap on the eyepiece of a unit to prevent condensation from forming on the optics.
3. Magnetic compasses display a compass reading directly on top of the night vision scene. It is automatically focused for simple operation, and is activated by a momentary-pressure switch that illuminates the compass bearings but does not degrade low-light viewing.
4. Sacrificial Windows, like UV filters in daylight photography, get put in front of the objective lens and prevent it from getting scratched. They are much less expensive than replacing an entire night vision device.
5. Auxiliary lenses for increasing the magnification of the device.
6. Beacons are infrared illuminators that are positioned in the landscape rather than on the night vision device. They can be used to define a trail or to flood an area with IR so the positions of the viewers are not revealed.
7. Camera Adapters allow cameras and camcorders to be attached to night vision devices for recording what you view.
8. Goggle Kits come in various configurations, but in general, include a head mount system of some kind, one or more auxiliary lenses, perhaps an extended range IR illuminator, camera or camcorder adapter, and a case.
9. Head Mounts have two basic flavors - strap systems that wrap around your head to keep the goggles in place in front of your eyes, and clamp systems for mounting the goggles to a military style helmet.
10. IR Illuminators, as mentioned above, are often built in to night vision devices, but these generally have limited range. Accessory illuminators are either used for devices that do not have them, or are more powerful for extended range. There are even IR spotlights with 1,000,000 candlepower.
11. Finally, there are the usual suspects such as cases, batteries, tripods, window mounts, lens caps and the other things typical of other hand-held optics.

Night Vision Care and Handling

Night vision devices are electronic instruments and will not stand careless or exceptionally rough use. Contrary to this many models are waterproof and have durable designs to withstand typical outdoor use. Those that are not specifically rated for damp conditions (waterproof or weather-resistant) may be damaged by exposure to water or even high humidity.

Night vision devices are not susceptible to, nor negatively affected by airport x-ray machines, and it is absolutely safe to pass a night-vision device through baggage security checks. First Generation (or Generation 1) devices may be taken in and out of the country freely. Second and third generation night vision devices are regulated by the State Department and their movements are restricted around the world. Consult proper authorities if planning to travel out of the country with a Generation 2 or higher device (night vision design generations are defined in the previous article).

Another level of caution for night vision devices is to avoid looking at bright lights or using them in the daylight as this can damage the units. As a general rule, if the unit is not equipped with a “gated” tube or it is bright enough to see without the device you should not be using it. Otherwise, looking directly at strong lights such as at powerful flashlights, car headlights, projectors and so on, can permanently damage the device. The majority of today’s night vision devices are equipped with special “cut off” circuitry to interrupt the power supply when the unit is exposed to bright light. Second and third generation devices also incorporate automatic image brightness control to help protect against accidental bright light exposure and subsequent damage.

Conclusions

• Night vision devices have many nighttime applications for consumers. The devices have opened the doors to seeing in the darkness and exploring nocturnal activities, at a reasonable cost, that were not possible before.
• Looking through night vision devices is different than the cameras and binoculars we are used to and take practice to use and operate.
• There are several optional devices that can be added to extend the capabilities, function and protect a night vision device.
• Night vision devices are electronic instruments that will not withstand excessive rough use. They might be considered closer to a nice camera for durability rather than a pair of binoculars.
  

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