Getting Started; Focusing - Celestron C5 Instruction Manual

G E T T I N G

Focusing

Figure 2-1
The decal on the end of the
focus knob shows the correct
rotational direction for
focusing the C5.
Once your spotting scope is fully assembled, you are ready for your first look. This
section deals with the basics of your spotting scopes operation.
The Celestron C5 spotting scope focusing mechanism controls the position of the
primary mirror which is mounted on a sleeve that slides back and forth on the
primary baffle tube (see figure 2-2). The focusing knob, which moves the primary
mirror, is on the rear cell of the C5 to the right of the diagonal and eyepiece. Turn
the focusing knob until the image is sharp. If the knob will not turn, the primary
mirror 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 (see figure 2-1). A single turn of the focusing knob moves the primary
mirror only slightly. Therefore, it will take many turns (about 40) to go from close
focus (approximately 20 feet) to infinity. For astronomical viewing, out-of-focus
star images are very diffuse making them difficult, if not impossible, to see. If you
turn the focus knob too quickly, you can go right through focus without seeing the
image. For best results, your first astronomical target should be a bright object (like
the Moon) so that the image is visible even when out of focus.
This diagram shows the focusing mechanism of the C5 spotting scope.
S T A R T E D
Figure 2 -2

Getting Started

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