5
Figure 1-5
The emblem on the end of
the focus knob shows the
correct rotational direction
for focusing your telescope
.
6.
Slightly tighten the three nylon tipped thumbscrews on the front ring of the bracket to hold the finder
in place.
7.
Once on, push the finder back until the O-ring is snug inside the back ring of the finder bracket.
8.
Hand tighten the three nylon tipped thumbscrews until snug.
Aligning the Finderscope
Accurate alignment of the finder makes it easy to find objects with the telescope, especially celestial objects. To
make aligning the finder as easy as possible, this procedure should be done in the daytime when it is easy to find and
identify objects. The finderscope has three adjustment screws that put pressure on the finderscope while adjusting
the finder horizontally and vertically. To align the finder:
1
Choose a target that is in excess of one mile away. This eliminates any possible parallax effect between the
telescope and finder.
2
Release the altitude and azimuth clamps and point the telescope at your target.
3
Center your target in the main optics of the telescope. You may have to move the telescope slightly to center it.
4
Adjust the screw on the finder bracket that is on the right (when looking through the finder) until the crosshairs are
centered horizontally on the target seen through the telescope.
5
Adjust the screw on the top of the finder bracket until the crosshairs are centered vertically on the target seen
through the telescope.
Image orientation through the finder is inverted (i.e., upside down and backwards left-to-right). This is normal for
any finder that is used straight-through. Because of this, it may take a few minutes to familiarize yourself with the
directional change each screw makes on the finder.
Focusing
The Schmidt-Cassegrain focusing mechanism controls the primary mirror which is
mounted on a ring that slides back and forth on the primary baffle tube. The focusing knob,
which moves the primary mirror, is on the rear cell of the telescope just below the star
diagonal and eyepiece. Turn the focusing knob until the image is sharp. If the knob will
not turn, it has reached the end of its travel on the focusing mechanism. Turn the knob in
the opposite direction until the image is sharp. Once an image is in focus, turn the knob
clockwise to focus on a closer object and counterclockwise for a more distant object. A
single turn of the focusing knob moves the primary mirror only slightly. Therefore, it will
take many turns (about 30) to go from close focus to infinity.
For astronomical viewing, out of focus star images are very diffuse, making them difficult
to see. If you turn the focus knob too quickly, you can go right through focus without
seeing the image. To avoid this problem, your first astronomical target should be a bright
object (like the Moon or a planet) so that the image is visible even when out of focus.
Critical focusing is best accomplished when the focusing knob is turned in such a manner
that the mirror moves against the pull of gravity. In doing so, any mirror shift is
minimized. For astronomical observing, both visually and photographically, this is done by
turning the focus knob counterclockwise.
C14 Users:
Before turning the focus knob, remember to lossen to two mirror locking knobs located on the rear cell of the
telescope. These knobs connect a screw to the primary mirror mounting plate and prevent the mirror from moving when locked
down. These screws should be locked down when transporting the telescope.
