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NIGHT VISION
CHARACTERISTICS
Monochromatic Image
Night Vision Devices produce a monochromatic
image. You will not be able to see any differ-
entiation between colors. In particular, red and
green lights will both appear green. Take care to
verify color differences with unaided vision. Ex-
ercise extreme caution when operating aircraft,
ground vehicles, or marine vessels while using
night vision equipment.
Color Sensitivity
Night Vision Devices are more responsive to
red and white lights than green and blue lights.
Because of this, distant red and white lights may
appear closer than green or blue lights. Exer-
cise extreme caution when using these lights for
navigation. Periodically verify the distances to
these lights with your unaided eyes.
Extreme Darkness
Night Vision Devices are effective under most
dark conditions including overcast starlight.
They are not practical in an extremely dark en-
vironment such as in a tunnel where there is no
natural ambient light. Without sufficient ambient
light, the operator may notice pinpoint-size spar-
kles (scintillation or noise) in the image area.
These sparkles are small amounts of energy
generated inside the image intensifier that strike
the phosphor screen and are an indication that
the device is working.
Contrast Reversal
Night Vision Devices detect light that cannot
be seen by the human eye. This light is often
referred to as being in the near-infrared light
spectrum. The existence of this light and the
manner in which it reflects is not normally visible
to the naked eye. For this reason, objects that
normally appear lighter than their surroundings
may appear dark against a light background. In
addition, the output image of the Night Vision
Device is dependent on the reflective quality
of the objects the operator sees in the viewing
area. Objects that appear light during the day
but have a dull surface may appear duller when
viewed through a Night Vision Device. All of
these factors must be taken into account when
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utilizing a Night Vision Device for observation or
navigation purposes.
Depth Perception
Night Vision does not present normal depth
perception. Use extreme caution when using a
Night Vision Device where reliance upon depth
perception is important.
Fog and Rain
Night Vision Devices are very responsive to
reflected ambient light; therefore, fog or heavy
rain can reflect too much light toward the Night
Vision Device and may seriously degrade its
performance.
Honeycomb
This is a faint hexagonal pattern throughout
the image area. This effect is more noticeable
under high light conditions. Do not be concerned
- the honeycomb effect is an inherent character-
istic of all high-amplification night vision systems
that incorporate a microchannel plate in the
intensifier.
Black Spots
These are cosmetic blemishes in the image
intensifier. They do not affect the performance
or reliability of a night vision device and a num-
ber of sizes are inherent in the manufacturing
process.
Image Intensifier Life
Night Vision Devices are designed to be robust.
The image intensifier tube, however, does not
have an unlimited lifetime. The life of the image
intensifier is dependent upon the amount of
use. Under normal operating conditions, it will
provide reliable performance for an extended
period of time.
MAINTENANCE
Optics
Always clean the optics with a suitable optical
cleaning cloth. Do not use detergents or exces-
sive moisture to clean any part of the Night Vi-
sion Device.
Battery/Battery Compartment
Any Night Vision Device that is to be stored for a
long or undetermined amount of time must have
the batteries removed.
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Moisture
The Night Vision Device is water resistant. No
warranties or guarantees apply to a Night Vision
Device that has been submerged in water. Take
great care when using any night vision in a wet
environment as the image intensifier tube is
sensitive to moisture.
Salt Water
If the Night Vision Device is exposed to a salt
water environment, wipe it off with a clean cloth
slightly dampened with fresh water and dry it
thoroughly. Take special care of the optics as
noted above.
Sunlight
Night Vision is sensitive to light and must be
stored away from direct contact with bright light
sources of any kind.
!WARNING!
Improper care or unauthorized
maintenance can damage device
and may result in warranty nullifi-
cation.
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TROUBLESHOOTING
Symptom Probable Cause Corrective Action
No visible Image a. Objective lens cap not been removed.
b. Battery cover is loose.
c. Incorrect battery polarity
d. Weak battery
a. Remove cap
b. Tighten cover
c. Re-insert battery
d. Replace battery
Image flickers, flashes, or
clicking is heard a. Normal for new battery to cause this for
first five minutes. a. If condition continues contact manufacturer for service
instructions
Dark spots on screen a. Cosmetic blemishes. Normal for this
technology. a. Acceptable as long as it does not interfere with opera-
tion of the device
Image not clear a. Focus is not adjusted.
b. Too close to object a. Adjust focus
b. Increase viewing distance.
Fixed pattern noise.
(honeycomb) a. Cosmetic blemishes caused by too mach
illumination. a. Acceptable as long as target resolution can be re-
solved.
Pattern of dark thin lines
(chicken wire) a. Normal under worst conditions. These
lines will form hexagonal or square wave-
shaved lines.
a. Acceptable as long as it does not interfere with opera-
tion of the device
Image dimmer than
usual. a. Weak batteries
b. Low natural illumination level. a. Replace the batteries.
b. Turn on IR illuminator.
