A. Bright Spots
A bright spot is a small, non-uniform bright area that may flicker or appear constant (Figure 4-3).
Not all bright spots make the NM-108 BC returnable. Cup your hand over the lens to block out all
light. If the bright spot remains, please contact Customer Support.
Bright spots usually go away when all light is blocked out. Verify that any bright spots are not simply
the result of bright light in the area you are observing. Bright spots are acceptable if they do not inter -
fere with the user’s ability to view the scene or perform missions.
Figure 4-3. EMISSION POINTS AND BRIGHT SPOTS
B. Emission points
Emission points are steady or fluctuating pinpoints of bright light in the image area that do not go
away when all external light is blocked from the objective lens (Figure 4-3). The position of an emis-
sion point within the image area does not move. Not all emission points are cause to return the NM-
108 BC. Verify that emission points are not simply light sources present in the scene you are observ-
ing. Emission points are acceptable if they do not interfere with the user’s ability to perform missions.
C. Black Spots
Black spots are cosmetic blemishes in the image intensifier or debris between the lenses. Black spots
are acceptable as long as they do not interfere with the user’s ability to observe the scene. No action is
required if this condition is present, unless the spots interfere with the operator’s ability to perform
missions.
D. Fixed-pattern Noise
Fixed-pattern noise is usually a cosmetic blemish characterized by a faint hexagonal (honeycomb)
pattern that appears throughout the viewing area. This typically occurs in excessively lit environments
or when viewing very bright lights (See Figure 4-4). This pattern can be seen in every image intensi-
fier if the level of light is high enough. This condition is acceptable as long as the pattern does not in -
terfere with the user’s ability to view an image or their ability to perform missions.
Figure 4-4.
FIXED PATTERN NOISE
