12
Optical finderscope assembly and alignment
Unthread two screws in the back of the telescope tube. Place the finderscope base above the holes on the
tube. Lock the finderscope base into position by tightening the screws (fig. 4).
Optical finderscopes are very useful accessories. When they are correctly aligned with the telescope,
objects can be quickly located and brought to the center of the view. Turn the scope end in and out to
adjust focus.
To align the finderscope, choose a distant object that is at least 550 yards (500 meters) away and point
the telescope at the object. Adjust the telescope so that the object is in the center of the view in
your eyepiece. Check the finderscope to see if the object is also centered on the crosshairs. Use three
adjustment screws to center the finderscope crosshairs on the object (fig. 7).
Focusing
Slowly rotate the focus knobs one way or the other until the image in the eyepiece is sharp. The image
usually has to be finely refocused over time due to small variations caused by temperature changes,
flexures, etc. Refocusing is almost always necessary when you change an eyepiece, add or remove a
Barlow lens (refractor 6a, reflector 6b).
Operating the mount
The AZ mount is an alt-azimuth mount that allows you to rotate the telescope about the vertical and
horizontal axes and change its altitude and azimuth. To adjust the azimuth, loosen the big locking knob
under the mount base and rotate the tube left or right about the axis then retighten it. Tighten the
altitude slow-motion control for more precise height adjustment. Then, rotate the knurled wheel on the
altitude slow-motion control rod.
For more precise motions use the altitude slow-motion control. Due to Earth’s movement, the objects
will be constantly shifting out of your view, so you will have to adjust the altitude and azimuth of your
telescope to continue your observations.
Reference materials usually list declination coordinates in degrees, hours and minutes above or below the
horizon line. Azimuth coordinates may sometimes be listed with the compass points (N, SW, ENE, etc.),
but it is more commonly listed in degrees around the 360-deg plane, where north is 0°, east is 90°, etc.
(fig. 8).
