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10 CHECKS AND ADJUSTMENTS
10-4 Perpendicularity of Line of sight to horizontal axis
Checks
qPosition a target Point A at a distance 30m - 50m away from the instrument,
and sight it with the telescope.
wLoosen the telescope lock screw and turn the telescope until a point is sighted
at a distance roughly equal to that of Point A.This is Point B.
eWith the telescope still reversed loosen the horizontal lock screw and rotate
the instrument around the vertical axis, and sight Point A again.
rLoosen the telescope lock screw and turn the telescope until a point is sighted
at a distance equal to that of Point B.This is Point C.
tNo adjustment is necessary if Point B and C are aligned.
Adjustments
qIf Points B and C are not aligned, mark Point D at 1/4 the length of the BC,
from Point C in the direction of Point B.
wUsing the adjustment pin, rotate the reticle adjustment screws horizontally
opposite each other (see preceding page), and move the reticle to sight Point
D.
eRepeat the check and make sure the adjustment is correct.
30 - 50m 30 - 50m
q
e
w
w
r
A
B
D
C
PENTAX R-300 (p65-88) 10/30/02 11:11 AM Page 69