Newcon Optik DN483 - Manual (Page 12)

9
below will help approximately estimate the shutter speed at the diaphragm of 2.0 for
your film:
Film sensitivity (ISO) 50 100 200 400 800 1600 3200
Shutter speed, sec. 1 1/2 1/4 1/8 1/15 1/30 1/60
Use ISO 400 film or higher. Usage of a tripod is strongly recommended to obtain
higher quality photos.
8. STORAGE AND MAINTENANCE
If Unit has been kept for a long time at temperatures lower than -40 °C (-40°F), then
prior to its using it must be warmed up at an ambient temperature of -10 °C (14°F) to
+40 °C (104°F) with relative humidity below 80%.
9. TROUBLESHOOTING
9.1 The scope does turn on
Check that the batteries are installed properly. Check the charge of the batteries.
Replace if they are weak. Do not mix old batteries with new ones.
9.2 The target does not appear in focus.
Bring the target to the center of the image. By turning the knob (8, Fig.1) achieves the
clearest target acquisition on the screen. If used with daytime scope re-focus it. Repeat
the focusing of DN 482/483 and scope if necessary.
If the image still does not seem to be in focus, clean the lenses. They could be foggy or
dusty.
9.3 Image has disappeared.
If the objective lens of switched on DN 482/483 is exposed to bright light it
automatically shuts off to protect the image intensifier tube from overload. When it
happens, turn the unit off, wait for a few seconds and turn it on again.
If the image has been lost at the moment of a shot, check contacts in the battery
compartment.
9.4 Condensation accumulates on the parts
In order to avoid misting of the eyepiece lens in the cold use special protective cover.
9.5 Black dots on the screen
These are the blemishes in the image intensifier, which do not affect the performance or
reliability of a night vision device. Blemishes may vary in size and number; those are
inherent in the manufacturing process. Most of them are seen in the daytime only and
become almost invisible during the night time.