Enclosure (2) to COMDTINST 1543.3
and some number of varying sizes are inherent in the manufacturing
processes. Spots due to dirt or debris between lenses should be
removed by careful cleaning if the system is designed to
open for interchanging optics.
Chicken wire is an irregular pattern of very thin, dark lines in
the field of view, either throughout the image area or in parts of
the image area. These lines are caused by fibers that do not
transmit light at the boundaries of fiber bundles in the optic of
the image intensifier. A minimal amount may sometimes be
found in some image intensifiers. It does not indicate a problem
in the device.
When you use night vision, your eye adjusts to the light output of the eyepiece. This means
that, when you remove the system, your aided eye, will not be adapted to darkness and so your
vision will be limited in the eye that was night vision-aided. It will normally take at least two
minutes to regain total unaided, dark-adapted vision.
Detection Distance
Relative Detection of a 6' Man
Full Moon
Quarter Moon
Starlight
PVS-14
890 yards
850 yards
601 yards
Unaided Eye
250 yards
50 yards
< 50 yards
You do not have the depth perception through a night vision device that you are used to with
your normal eyesight. The primary reason for this is the fact that you are actually looking at a
flat (two dimensional) picture tube called a phosphor screen. You can easily see this by
focusing your night vision device on a close-in object. Try reaching out to touch the object and
you will experience the depth perception difficulty. Fortunately, with time-spent training using
night vision equipment, your brain will help you compensate for this lack of depth perception.
This limitation may not completely go away, but with training, it will become less of an issue.
Also, using monocular systems can improve depth perception over binocular devices, since the
unaided eye can provide additional visual cues.
Image intensification night vision equipment is not designed to see through fog and smoke or
heavy rain or snowfall, which reflect ambient light. As a general rule, you can see through
rain, snow, fog, or dense smoke at night with your night vision just about as well as you can
see through the same fog and smoke during daylight with your normal eyesight. Using
supplemental IR illumination will not help- in fact, it will make it harder to see, just like using
your high-beams would when driving in foggy or smoky conditions.
With PVS-14 MNVD, visual acuity is typically not an issue; it provides 20/20 visual acuity
under most conditions. With older technology, however, it is an important consideration.
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