F. Using the Bearing Compass
1.
To read the bearing compass:
When you look through the left eyepiece, you will see a bearing compass window
with figures and graduations below the field of view. The bearing compass shows
directions as angles: north is 0º, east is 90º, south is 180º and west is 270º. Each grad-
uation mark in the compass represents 1º.
To determine an object’s direction, first align the object with the rangefinder scale in
the center of the field. Then read the compass, reading the graduation mark that lines
up with the reference line in the center of the bearing compass.
Note:
the compass is oriented to “magnetic north,” which differs from “true north.”
True north is the same throughout the world, while magnetic north varies depending
on location.
2.
To locate your position:
These binoculars, together with a map and protractor,
can be used to locate your position. For example, the
binoculars plus the map in Fig. 4 could be used to
determine the location of a boat sailing within the
map’s area.
a.
First, from the boat, use the binoculars to locate the
buoy shown on the map. In this example, the bearing
compass would show that the buoy is located 190º
from the boat.
b.
Use this information to determine the direction from
the buoy to the boat. (To do this, subtract 180º if the
object’s reading is 180º or greater; add 180º if the read-
ing is less than 180º.) So, 190º (direction from boat to
buoy) - 180º = 10º (direction from buoy to boat).
c.
On the map, draw a line from the buoy extending in
a 10º direction (10º from magnetic north). You now
know your boat is somewhere along this line (Fig. 5).
d.
To determine your boat’s exact position, use the
binoculars to locate a second object, the lighthouse. The
bearing compass will show that the direction from your
boat to the lighthouse is 300º.
e.
Then calculate the direction from the lighthouse to
your boat: 300º - 180º = 120º.
f.
Finally, draw a line extending 120º from the light-
house (Fig. 6). Your boat is located at the point where
the two lines intersect.
3.
Compass light:
To read your compass in the dark, press the compass light
switch (6), which will illuminate it in red light. If the light
becomes faint, change the light battery (LR43 X 2, alka-
line batteries). Unscrew the cover of the battery compart-
ment (7) and change the battery.
A. Eyepiece Distance Adjustment
For best viewing, the binoculars should be adjusted for the individual user so that eye-
pieces line up with the user’s eyes:
1.
Hold the binoculars in a normal viewing position.
2.
Grasp each barrel firmly. While looking through the binoculars, adjust the barrels until
you see a single, circular field of view. Reset the binoculars to this position each time
you use them. The eye distance setting is indicated on the scale located on the
binocular hinge.
B. Diopter Setting and Center Focus
1.
Set the right eyepiece (2) to zero and look at a distant object.
2.
Keeping both eyes open, cover the right objective (front) lens with your hand, then
adjust the center focus wheel until an image in the left eyepiece appears sharp.
3.
Cover the left objective (front) lens with your hand, then rotate the right eyepiece until
the image appears sharp again.
4.
Diopter setting is now correct for your eyes, and you need only adjust the center focus
to view objects at different distances. Note the diopter setting for future use.
C. Roll-down Eyecups
To use binoculars while wearing eyeglasses or sunglasses, roll down the eyecups (1).
This will allow you to bring your eyes closer to the binoculars, improving your field of
view.
D. Floating Strap
Prior to water activities, make sure the floating strap is securely attached to the binocu-
lars. This strap is designed to keep binoculars afloat if they are dropped into the water.
E. Reading the Rangefinder Scale
The rangefinder scale is a useful navigation tool if you know the size or distance of an
object. If you know an object’s size, you can use the rangefinder to calculate its distance.
Conversely, if you know the object’s distance, the rangefinder can tell you its size.
1.
To measure distance, simply apply the following formula:
Distance =
100 x Object Height
Rangefinder Scale Reading
Example: if the object is 20 meters high and the rangefinder
scale reading is 1.6 (Fig. 3), then:
20 M (height) x 100
= 1,250 M (distance)
1.6 (rangefinder scale reading)
2.
To measure size, the formula becomes:
Object Size = Distance x Rangefinder Scale Reading
100
Example: if the object is 1,250 meters away and the rangefinder scale reading is 1.6, then:
1,250 M (distance) x 1.6 = 20 M (object size)
100
Fig. 3
Fig. 4
Fig. 5
Fig. 6
