5
INSTALLING THE DIAGONAL AND EYEPIECE (REFRACTOR)
INSTALLING AND USING THE BARLOW LENS
The diagonal is a prism that diverts light at a right angle to the light path of the
refractor. This allows you to observe in a position that is more comfortable than if you
had to look straight through. This diagonal is an erect image model that corrects the
image to be right side up and oriented correctly left-to-right which is much easier to
use for terrestrial observing. Also, the diagonal can be rotated to any position which is
most favorable for you. To install the diagonal and eyepiece:
1. Insert the small barrel of the diagonal into the 1.25”
eyepiece adapter of the focus tube on the refractor –
Figure 2-13. Make sure the two thumbscrews on the
eyepiece adapter do not protrude into the focuser tube
before installation and the plug-up cap is removed from
the eyepiece adapter. Once in place, tighten the
thumbscrews to hold the diagonal in place.
2. Put the chrome barrel end of one of the eyepieces into
the diagonal and tighten the thumb screw. Again, when
doing this make sure the thumbscrew is not protruding
into the diagonal before inserting the eyepiece.
3. The eyepieces can be changed to other focal lengths by
reversing the procedure in step 2 above.
Your telescope also comes with a 3x Barlow Lens which triples the magnifying
power of each eyepiece. To use the Barlow lens, remove the diagonal and insert
the Barlow directly into the focuser tube. You then insert an eyepiece into the
Barlow lens for viewing. You can also, insert the diagonal into the Barlow lens
and then use an eyepiece in the diagonal, but you may not be able to reach
focus with all eyepieces.
NOTE: Start by using a low power eyepiece as it will be easier to focus.
Figure 2-13
Figure 2-16
3x Barlow Lens
