Installing The Visual Accessories; The Visual Back; The Star Diagonal - Celestron Ultima 11 Instruction Manual

INSTALLING THE VISUAL ACCESSORIES

Installing the oculars and other visual accessories is the same for both the Ultima 9
difference is that the rear cell, for the Ultima 11, is 3.290 inches in diameter and requires a reducer plate.
The reducer plate adapts the rear cell to the Celestron two inch standard. The Ultima 11 comes with the
reducer plate installed.

The Visual Back

The visual back allows you to attach most visual accessories to the telescope. If you use an 1-1/4" star
diagonal or if you want to insert the eyepiece into the telescope without a diagonal, then the visual back
attaches to the standard 2 inch rear cell on the back of the telescope (see figure 2-8). To attach the visual
back:
1. Remove the protective cap from the back of your telescope. It is pressed onto the rear cell.
2. Place the slip ring on the visual back over the threads on the rear cell.
3. Tighten by rotating the slip ring clockwise until tight.
Once this is done, you are ready to attach other accessories such as eyepieces, and diagonal prisms. If you
want to remove the visual back, rotate the slip ring counterclockwise until it is free of the rear cell.
2. Slide the chrome portion of the star diagonal into the visual back.
3. Tighten the thumbscrew on the visual back to hold the star diagonal in place.
If you wish to change the orientation of the star diagonal, loosen the thumbscrew on the visual back until the
diagonal rotates freely. Rotate the diagonal to the desired position and tighten the thumbscrew.
18
Figure 2-8
Telescope Basics
1
/ and the 11. The only
4

The Star Diagonal

The star diagonal is a prism
that diverts the light at a
right angle from the light
path of the telescope. For
astronomical observing, this
allows you to observe in
positions that are more
comfortable than if you were
to look straight through. To
attach the star diagonal:
1. Turn the
thumbscrew on the
visual back until its
tip no longer
extends into (i.e.,
obstructs) the inner
diameter of the
visual back.