12
Installing the Eyepieces
The eyepiece, or ocular as it is also called, is an
optical element that magnifies the image focused
by the telescope. Without the eyepiece it would be
impossible to use the telescope visually. The
eyepiece fits directly into the eyepiece holder. To
attach the eyepiece:
1. Loosen the set screw on the eyepiece holder so
that it does not obstruct the inner diameter of
the eyepiece holder.
2. Slide the chrome portion of the eyepiece into the
eyepiece holder.
3. Tighten the set screw to hold the eyepiece in
place.
To remove the eyepiece, loosen the set screw on the eyepiece holder and slide the eyepiece out. You
can replace it with another ocular.
Eyepieces are commonly referred to by focal length which is printed on the eyepiece barrel. The longer
the focal length (i.e., the larger the number) the lower the eyepiece power and the shorter the focal length
(i.e., the smaller the number) the higher the magnification.
Generally, you will use low-to-moderate power when viewing.
The StarHopper 8”, 10” and 12” can use eyepieces with both an 1-
1/4" barrel diameter and 2" barrel diameter. To use a 2" barrel
eyepiece, the 1 1/4" eyepiece adapter must first be removed. To
do this, simply loosen the two chrome thumbscrews located around
the focuser barrel and remove the 1 1/4" adapter. Once removed,
a 2" eyepiece can be inserted directly into the focuser barrel and
secured with the two thumb screws.
Using The Cooling Fans (Starhopper 10” and 12”
Only)
The StarHopper 10” and 12” telescopes come with a built-in cooling fan located on the rear cell of the
optical tube. This fan greatly reduces the damaging tube currents inside the tube as well as shortening the
time it takes for the optics to reach thermal equilibration. For more information on the affects of tube
currents and “seeing” refer to the
Celestial Observing
section later in this manual.
The cooling fan comes with its own battery pack using 8 user
supplied AA batteries. To power the fan simply plug the power
pack into the power outlet located on the fan.
Note
: The cooling fans are used to help the telescope reach
thermal equilibration and should not be used while observing
through the telescope. It is best to let the fan run prior to uses
while the tube is cooling down.
Figure 8 – Inserting the Eyepiece
1 ¼” adapter
2” Focuser
Figure 9 – Two inch Focuser
Cooling fan
Figure 10 – Cooling Fan
