Celestar Manual
Assembling your Celestar
17
The Eyepieces
The eyepiece, or ocular, is the optical element that
magnifies the image focused by the telescope.
The eyepiece fits either into the visual back
directly or into the star diagonal. To install an
eyepiece:
1.
Loosen the thumbscrew on the star diagonal
so that it does not obstruct the inner diameter
of the eyepiece end of the diagonal.
2.
Slide the chrome portion of the eyepiece into
the star diagonal.
3.
Tighten the thumbscrew on the diagonal to
hold the eyepiece in place.
To remove the eyepiece, loosen the thumbscrew
on the star diagonal and slide the eyepiece out.
In addition to barrel diameter, eyepieces are also referred to in terms of their focal length. The focal length
of each eyepiece 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. For more information on
how to determine power, see the section on “Calculating Magnification.”
Barrel diameter is the diameter of the barrel that slides into the star diagonal. Standard barrel diameters are
.96”, 1.25”, and 2”. The Celestar 8 and Celestar Deluxe 8 come standard for use with 1.25” barrel
eyepieces.
Figure 2-9
