(2) Wing nuts for locking the mirror cell into the main optical tube.
1. Turning the entire telescope and mount horizontally until the Polar Axis points to
due-North, and
2. Tilting the Polar Axis at an angle equal to your latitude.
Approximately equivalent to Steps 1 and 2 above is simply turning the entire telescope and mounting so that
the telescope Polar Axis points at the North Star. This method is completely satisfactory for all visual
observations.
Operation of the Telescope: Once the telescope Polar Axis is aligned with the Pole, this alignment should
remain unchanged throughout the observing session. To move from object to object, the observer turns the
telescope in declination and/or right ascension until the desired object is in the field of view. If you ordered an
optional viewfinder (see "Optional Equipment," below) with your DS-10, this small "sighting scope" will be
helpful in the location of astronomical objects. If your telescope is not equipped with a viewfinder, then simply
sight along the main tube (using a low-power eyepiece); with a little practice, this technique is more than
satisfactory.
The declination lock (7) should be tightened sufficiently to keep the telescope from moving, but it is not
necessary that the telescope be rigidly locked in declination. This lock provides a comfortable "drag" in
declination, so that the telescope will not turn too easily around this axis. On DS-10's not equipped with motor
drive, the R.A. lock, located on top of the polar casting (18), may similarly be used to cause a smooth "drag" in
right ascension.
Tracking Astronomical Objects: If your DS-10 is not equipped with the optional electric motor drive, then
the tracking of astronomical objects is performed simply by moving the telescope manually about the
telescope's polar axis, only. With the telescope mount aligned to the Pole, as described above, it is not
necessary to move the telescope in declination, in order to follow celestial objects. Once an object is centered
in the telescope's field of view, tracking an object (in order to compensate for its apparent motion caused by the
Earth's rotation) is performed by motion only about the telescope's polar axis.
If your telescope is equipped with the optional electric motor drive, you may, once the telescope has been
aligned with the Pole, plug in the electric motor drive for fully automatic tracking. The motor will start running
as soon as the telescope is plugged into a standard AC outlet. Because the stars move slowly, you will not be
able to detect the telescope's motion caused by the motor drive. With the drive plugged in, an object in the
telescope's field of view will appear to "stand still." When the drive is unplugged, the object will move out of
the field rapidly.
The drive system has a built-in automatic clutch, so that even when the drive is plugged in, you may still move
the telescope manually at will in any direction. When you release manual contact with the telescope, the drive
will automatically resume tracking.
Eyepieces and Focusing: The focal point of the DS-10 telescope has been intentionally set beyond the normal
travel of the standard focusing mechanism. By setting the focal point in such a position, it is not necessary to
move the primary mirror for so-called "prime-focus" astrophotography, as will be discussed below. However, in
order to use standard eyepieces for normal visual observations through the DS-10, it is necessary to use an
eyepiece extender tube to achieve correct focus. This eyepiece extender tube is included as standard equipment
with the telescope and positions an eyepiece further out from the focuser so that correct focus can be reached.
Note: With some eyepieces of about 25mm focal length or longer, it may be necessary to pull the eyepiece out
slightly from the extender tube in order to reach correct focus.
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