Celestron C80ED-R, C100ED-R manual Adjusting the Mount, Balancing the Telescope in DEC

Balancing the Telescope in DEC

The telescope should also be balanced on the declination axis to prevent any sudden motions when the DEC clamp (Fig 2-5) is released. To balance the telescope in DEC:

1.Release the R.A. clamp and rotate the telescope so that it is on one side of the mount (i.e., as described in the previous section on balancing the telescope in R.A.).

2.Lock the R.A. clamp to hold the telescope in place.

3.Release the DEC clamp and rotate the telescope until the tube is parallel to the ground (see figure 2-13).

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.Loosen the screws that hold the telescope tube inside the mounting rings and slide the telescope either forwards or backwards until it remains stationary when the DEC clamp is released.

6.Tighten the tube ring screws firmly to hold the telescope in place.

Figure 2-12 Figure 2-13

Like the 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.

Adjusting the Mount

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.”

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