Celestron C8-S User Manual
Page 14
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3.
Loosen the DEC clutch lock lever and rotate the telescope until the tube is parallel to the
ground.
4.
Release the tube — GRADUALLY — to see which way it rotates around the declination
axis. DO NOT LET GO OF THE TELESCOPE TUBE COMPLETELY!
5.
Slightly loosen the knobs that holds the telescope to the mounting platform and slide the
telescope either forward or backward until it remains stationary when the DEC clutch is loose.
Do NOT let go of the telescope tube while the knob on the mounting platform is loose. It may
be necessary to rotate the telescope so that the counterweight bar is pointing down before
loosening the mounting platform screw.
6.
Tighten the knobs on the telescope mounting platform to hold the telescope in place.
Like R.A. balance, these are general balance instructions and will reduce undue stress on the mount. When
taking astrophotographs, this balance process should be done for the specific area at which the telescope is
pointing.
A
A
d
d
j
j
u
u
s
s
t
t
i
i
n
n
g
g
t
t
h
h
e
e
M
M
o
o
u
u
n
n
t
t
In order for a motor drive to track accurately, the telescope’s axis of rotation must be parallel to the Earth’s
axis of rotation, a process known as polar alignment. Polar alignment is achieved NOT by moving the
telescope in R.A. or DEC, but by adjusting the mount vertically, which is called altitude, and horizontally,
which is called azimuth. This section simply covers the correct movement of the telescope during the polar
alignment process. The actual process of polar alignment, that is making the telescope’s axis of rotation
parallel to the Earth’s, is described later in this manual in the section on “Polar Alignment.”
Adjusting the Mount in Altitude
•
To increase the latitude of the polar axis, tighten the rear latitude adjustment screw and loosen the front
screw (if necessary).
•
To decrease the latitude of the polar axis, tighten the front (under the counterweight bar) latitude
adjustment screw and loosen the rear screw (if necessary).
The latitude adjustment on the CG-5 mount has a range from approximately 30° going up to 60°.
It is best to always make final adjustments in altitude by moving the mount against gravity (i.e. using the
rear latitude adjustment screw to raise the mount). To do this you should loosen both latitude adjustment
screws and manually push the front of the mount down as far as it will go. Then tighten the rear adjustment
screw to raise the mount to the desired latitude.
For Advanced GT users, it may be helpful to remove the front latitude adjustment screw completely. This
will allow the mount to reach lower latitudes without the screw coming into contact with R.A. motor
assembly. To remove the latitude screw, first use the rear screw to raise the mount head all the way up.
Then remove the front latitude screw completely. Now you should
be able to manually move the mount head all the way to it lowest
latitude. Now, using only the rear screw, raise the mount to your
desired latitude.
Adjusting the Mount in Azimuth
For rough adjustments in azimuth, simply pick up the telescope and
tripod and move it. For fine adjustments in azimuth:
1. Turn the azimuth adjustment knobs located on either side of the
Figure 2-14
Azimuth
Adjustment
Knobs
Rear Latitude
Adjustment
Screws
Front Latitude
Adjustment Screw