National Geographic Binoculars Owner's Manual - page 4
All National Geographic binoculars are coated with rubber to protect against minor bumps and
scrapes and to provide a non-slip gripping surface. To withstand harsher conditions, the
waterproof binoculars have been designed with a thicker rubber covering.
Waterproof and fog-resistant binoculars:
To meet the needs of boaters, campers, and those who use binoculars in more extreme weather
conditions, the waterproof models offer an additional design feature. A special manufacturing
process uses inert, dry nitrogen gas to replace the air inside the binoculars—eliminating any
water vapor and stopping the binoculars from fogging over on the inside. The optical tubes have
then been hermetically sealed to prevent damage from rain, snow, or water. Note: Although
these binoculars are waterproof and designed to survive accidental submersion in water,
they do not float. The binoculars should be retrieved immediately.
Tripod adapter:
Many full-size National Geographic binoculars feature a tripod adapter
socket. This threaded metal socket accepts a standard tripod adapter so you
can attach it to any standard photo/video tripod for added stability. The
adapter socket is located behind the round plug between the two lens barrels.
Zoom:
The NG1236ZT is a zoom binocular providing an area magnification* range
of 36X to 108X. The magnification power can be set to the 36X setting, the
108X setting, or anywhere in between. Having a zoom binocular is like
having many different binoculars in one easy to use package.
To operate the zoom feature and change the magnification power on the
NG1236ZT, simply move the zoom control lever up or down until the indicator lines up with the
desired magnification power. The zoom control lever is located by the right eyepiece. Note that as
the magnification power is increased the brightness of the viewed image will decrease somewhat.
Higher zoom powers should only be used in situations where the subject is brightly illuminated.
The NG1236ZT is a more compact zoom binocular with a zoom range of 6X to 13X.
• See the following section on “Optical Magnification”.