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
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
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:
- AC power adapters.
Demist shields that snap
on the eyepiece of a unit to prevent condensation from forming on the
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
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.
Auxiliary lenses for increasing
the magnification of the device.
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.
Camera Adapters allow cameras
and camcorders to be attached to night vision devices for recording
what you view.
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.
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.
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.
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.
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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