6
Erecting Prism
:
You may convert your instrument to a razor-sharp terrestrial
telescope by replacing the star diagonal with an erecting prism. Unlike the star
diagonal, the erecting prism will provide a correctly oriented view through the
eyepiece. So while we do not recommend an erecting prism for viewing at night,
we highly recommend them for daytime viewing.
Pictured to the left is the D1035 45 degree, 2” erecting prism.
The Star Diagonal
:
The Stellarvue D1040Q diagonal uses a thick and
accurate 1/10 wave low expension quartz mirror with a 99% dielectric
coating. Astronomers prefer mirror star diagonals over prisms because
they are sharper and provide the highest con-
trast. Mirror star diagonals present an image
that is right side up but reversed left to right.
Vic Maris designed the D1040Q diagonal
body over a two year period. It is made with
an adjustment mechanism that allows our
Stellarvue assemblers to attain perfect align-
ment. It also cushions the mirror to eliminate
pinching. All of this is critical if one wants to
attain the highest level of performance.
SETTING UP FOR VISUAL USE
Now that you have securely attached the telescope to the mount, you will need to balance it in both axes. The
mount manual explains how to do this. If you are using an equatorial and/or go-to computerized mount, you
will need to align the telescope according to the mount manual to get it ready for use. Once the telescope is
balanced and the mount aligned, you are ready to observe!
Two additional optical components are necessary to be able to view through
your telescope at night: a star diagonal and an eyepiece.
* The star diagonal reflects the light 90 degrees. Without it the viewer would
be forced to look upward when viewing and this would be extremely
uncomfortable.
* The eyepiece is needed to focus and magnify the image.
The star diagonal is inserted into the focuser, and the eyepiece is then inserted into the star diagonal.
Stellarvue #D1040Q two inch
dielectric quartz star diagonal
1 1/4”
Adapter
Star
Diagonal
Eyepiece
2” Adapter
Thumb Screw
If using a 2” star diagonal, loosen
the three 2 inch adapter thumb
screws and remove the 1 1/4”
adapter.
Install the star diagonal and
make sure it is held in place
tight by securing the three 2”
adapter thumb screws.
Insert the eyepiece into the star diagonal
as shown. Make sure the thumb screw
on the diagonal holds the eyepiece in
place securely.
