Navox 79 27 21, Инструкция по эксплуатации

Страница: 10 / 18

6
Feature Explanation
Magnification
Prismatic binoculars are defined to a combination of numbers, here 10x50
mm. The 10 indicates the magnification and the 50 is for the diameter of
the front lens in millimetres. This diameter determines how much light can
enter into the optical system.
Twilight Output
The twilight output is an important factor to quantify the ability how much
details you can see in dim light. The higher the value, the more you can
see details in twilight. The factor is found by multiplying the objective lens
diameter by the magnification and then finding the square root of that
product. In this case the value is 22.4. With this feature the binoculars is
perfect for viewing objects in dim light conditions.
Exit Pupil
The exit pupil is the size of a virtual aperture, from which rays pass
through binoculars. To find the exit pupil size, divide the diameter of the
objective lens by the magnification, in this case approx 5 mm. You can
see the exit pupil if you hold the binoculars approx. 20 cm away from the
eyes and look into a bright afterimage. You will see a bright circle in the
centre of the lens. The larger the exit pupil is, the brighter the image will
be while observing the object.
Angle of Vision
The FOV (field of view)
is indicated in a dis-
tance of 1000 m. The
unit has a FOV of 100
m at 1000 m distance
and an angle of vision
of approx. 5.7º.
Angle of Vision
FOV