Vixen BT80M - Manual (Page 2)

Vary the magnification by using other Vixen NLV Eyepieces. However, these are not marked
with aligning dots for collimating the optical axes. The following adjustment may be required.
Look through the left eyepiece and find an object in ex-
cess of 1000 yds away. Bring the object to the right edge
of the horizontal center in the field of view. Then look
through the right eyepiece. If the object is seen at a level
with the image of the left eyepiece, the optical collimation
is good. If not, rotate the right eyepiece slowly clockwise
or counter clockwise until it is seen at a level with the im-
age in the left eyepiece.
If it is not possible to level it with the image of the left
eyepiece by rotating the right eyepiece. Try to do the
same adjustment as the above by rotating the left eyepiece.
Note: At a low power, an object can be seen clearly and brightly. It is advisable to being
with a low power eyepiece having a long focal length and to change it gradually to a high
power eyepiece having a short focal length. When using the nlv25mm eyepiece on the Vixen
BT80M-A, power will by 36x which is fairly high in comparison with magnification of ordi-
nary binoculars.