Celestron Omni XLT AZ 102 Instruction Manual - Page 14

Installing the Star Diagonal The star diagonal is a prism that diverts the light at a right angle to the light path of refractors and Schmidt- Cassegrain telescopes. This allows you to observe in positions that are physically more comfortable than if you looked straight through. Eyepiece To attach the star diagonal onto the optical tube of a Schmidt- Cassegrain: 1. Turn the set screw on the visual back until its tip no longer extends into (i.e., obstructs) the inner diameter of the visual back. 2. Slide the chrome portion of the star diagonal into the visual back. 3. Tighten the set screw on the visual back to hold the star diagonal in place. Star Diagonal Visual Back If you wish to change the orientation of the star diagonal, loosen the set screw on the visual back until the star diagonal rotates freely. Rotate the diagonal to the desired position and tighten the set screw. Figure 2-11 Refractors - To use the star diagonal on refractor telescopes, it is inserted into the 1 ¼" eyepiece adapter. Installing the Eyepieces The eyepiece, or ocular as it is also called, is an optical element that magnifies the image focused by the telescope. Without the eyepiece it would be impossible to use the telescope visually. The eyepiece fits directly into the focuser of refractors and the Newtonian or into the visual back on the Schmidt-Cassegrain To attach an ocular: Focuser Tension 1. Loosen the set screw on the eyepiece adapter so that it does not obstruct the inner diameter of the barrel. Screw 1 ¼" Eyepiece Adapter 2. Slide the chrome portion of the eyepiece into the focuser. 3. Tighten the set screw to hold the eyepiece in place. To remove the eyepiece, loosen the set screw on the focuser and slide the eyepiece out. You can replace it with another ocular. Focuser Knob T-Adapter Thread 2" Focuser Barrel Many times it will be more comfortable to use a star diagonal on the refractors and Schmidt-Cassegrain for most areas of the sky. To install an eyepiece into the star diagonal: Figure 2-12 A. Loosen the set screw on the star diagonal until the tip no longer extends into the inner diameter of the eyepiece end of the diagonal. B. Slide the chrome portion of the eyepiece into the star diagonal. C. Tighten the set screw on the star diagonal to hold the eyepiece in place. D. To remove the eyepiece, loosen the set screw on the star diagonal and Slide the eyepiece out. You can replace it with other optional eyepieces. 14