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 rec-
ommend them only for daytime viewing.
The Star Diagonal
:
The Stellarvue D1040Q diagonal uses a thick
and accurate 1/10 wave low expension quartz mirror with a 99%
dielectric coating. These diagonals are assembled and tested here at
Stellarvue to ensure they maintain your telescope’s performance.
Astronomers prefer mirror star diagonals over prisms because they
are sharper an provide the highest contrast. Mirror star diagonals
present an image that is right side up but reversed left to right. For
newbies this takes a little practice, but it is worth the effort because it
will allow you to see more de-
tail at night.
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 observing and this would be extremely
uncomfortable.
* The eyepiece is needed to focus the image and magnify it.
Stellarvue #D1040Q two inch
dielectric quartz star diagonal
Stellarvue #D1035 two inch
correct-image erecting prism
1 1/4”
Adapter
Plug
Tightening Lever
Thumb
Screw
Remove the plug. If using a 2” star
diagonal, remove the 1 1/4” adapter.
Insert the star diagonal into the focuser.
Secure it using the tightening lever.
Insert the eyepiece into the star
diagonal. Tighten the thumb screw.
