Orion 9968 instruction manual Polar Alignment Using an Optional Polar Axis Finder Scope

	Eyepiece	Alignment	Focus	Objective
Azimuth	focus ring	setscrews (3)	lock‑ring	lens
adjustment
knobs

Figure 8. For polar alignment, position the tripod so that the "N" label at the base of the mount faces north. The azimuth fine adjustment knobs above it are used to make small adjustments to the mount’s azimuth position. Be certain to loosen the tripod attachment knob on the central support shaft before adjusting these knobs.

Observers in the Southern Hemisphere aren’t so fortunate to have a bright star so near the south celestial pole (SCP). The star Sigma Octantis lies about 1° from the SCP, but it is barely visible with the naked eye (magnitude 5.5).

For general visual observation, an approximate polar align‑ ment is sufficient.

1.Level the equatorial mount by adjusting the length of the three tripod legs.

2.There are two latitude adjustment L-bolts (see Figure 6); loosen one while tightening the other. By doing this you will adjust the latitude of the mount. Continue adjusting the mount until the pointer on the latitude scale is set at the latitude of your observing site. If you don’t know your lati‑ tude, consult a geographical atlas to find it. For example, if your latitude is 35° North, set the pointer to 35. The lati‑ tude setting should not have to be adjusted again unless you move to a different viewing location some distance away.

3.Loosen the Dec. lock lever and rotate the telescope’s opti‑ cal tube until it is parallel with the right ascension axis, as it is in Figure 6.

4.Move the tripod so the telescope tube and right ascen‑ sion axis point roughly at Polaris. If you cannot see Polaris directly from your observing site, consult a compass and rotate the tripod so the telescope points north. There is a label bearing a large “N” at the base of the equatorial mount (Figure 8); it should be facing north.

The equatorial mount is now polar aligned for casual observ‑ ing. More precise polar alignment is recommended for astro‑ photography. For this we suggest using the optional polar axis finder scope

From this point on in your observing session, you should not make any further adjustments to the latitude of the mount, nor should you move the tripod. Doing so will undo the polar alignment. The telescope should be moved only about its R.A. and Dec. axes.

Figure 9. The optional polar axis finder scope.

Polar Alignment Using an Optional Polar Axis Finder Scope

The SkyView Pro 150mm EQ mount can be equipped with an optional polar axis finder scope (Figure 9) which goes inside the right ascension axis of the mount. When properly aligned and used, it makes accurate polar alignment quick and easy to do.

To install the polar axis finder scope, remove the cover at the rear of the mount’s right ascension axis (Figure 9) and thread the polar axis finder scope into the equatorial mount until tight.

The reticle of the polar axis finder scope for the SkyView Pro has a tiny star map printed on it that makes precise polar alignment quick and easy. If you do not have a clear view of Polaris from your observing site, you will not be able to use the polar-axis finder to precisely polar align the telescope. To align the mount using the polar axis finder scope, follow these instructions:

Alignment of the Polar Axis Finder Scope

1.Look through the polar finder at a distant object (during the day) and center it in the crosshairs. You may need to adjust the latitude adjustment L-bolts and the tripod posi‑ tion to do this.

2.Rotate the mount 180º about the R.A. axis. Again, it may be convenient to remove the counterweights and optical tube first.

3.Look through the polar finder again. Is the object being viewed still centered on the crosshairs? If it is, then no further adjustment is necessary. If not, then look through the polar finder while rotating the mount about the R.A. axis. You will notice that the object you have previously centered moves in a circular path. Use the three align‑ ment setscrews on the polar axis finder to redirect the crosshairs of the polar finder to the apparent center of this circular path. Repeat this procedure until the position that the crosshairs point to does not rotate off-center when the mount is rotated in R.A. Once this is accomplished, snug the setscrews so the alignment is secure.

The polar axis finder scope is now ready to be used. When not in use, replace the plastic protective cover to prevent the

8