Orion 8727 Instruction Manual

Orion High-Reflectivity Mirror
Star Diagonals
#8727 2" version w/dielectric coatings
#8879 1.25" version w/enhanced aluminum coatings
#8880 1.25" version w/dielectric coatings
Congratulations on your purchase of a high-quality Orion star
diagonal. Your diagonal utilizes a precision flat mirror with high-
reflectivity coatings and top quality machined housings. Using a
star diagonal with your telescope provides a comfortable view-
ing angle for astronomical observation. In addition, a diagonal
is required to reach focus in many short-focal length refractors.
The diagonal will work with refractors, Schmidt-Cassegrains, and
Maksutov-Cassegrains, but not Newtonian reflector telescopes.
How to Use the Star Diagonal
Remove the cover caps and place the barrel of the star diagonal
directly into the telescope's focuser. Secure it in place with the
thumbscrew(s) on the focuser. Insert your eyepiece into the of
the diagonal and secure the eyepiece with the diagonal's thumb-
screw. Notice there is a brass compression ring inside the open-
ing of the diagonal, interior to the thumbscrew. This ring prevents
the thumbscrew from marring the barrel of your eyepiece.
If you would like to adjust the position of the diagonal to accom-
modate observers of different heights, simply loosen the
thumbscrew(s) on your telescope's focuser, rotate the diagonal,
and re-secure your telescope's thumbscrew(s). Before rotating the
diagonal, however, make sure the thumbscrew on the diagonal is
tightened, or the eyepiece may fall out and onto the ground!
Barrel
1.25" Eyepiece adapter
The Orion 2" High Reflectivity Mirror Star Diagonal
A N E M P L O Y E E - O W N E D C O M P A N Y
Copyright © 2021 Orion Telescopes & Binoculars. All Rights Reserved. No part of this product instruction or any of its contents
may be reproduced, copied, modified or adapted, without the prior written consent of Orion Telescopes & Binoculars.
INSTRUCTION MANUAL
Brass compression rings
Thumbscrews
Barrel
The Orion 1.25" High Reflectivity Mirror Star Diagonal
The 2" star diagonal will accept either 2" or 1.25" eyepieces using
the supplied 1.25" eyepiece adapter. If using 2" eyepieces, remove
the 1.25" adapter from the diagonal.
Focusing
Focus with your telescope's focusing knob. The 1.25" diagonal
requires approximately 9cm inward focus travel relative to the
eyepiece's focus position without the diagonal. The 2" model will
require slightly more inward focus travel, as it requires approxi-
mately 11cm relative to the eyepiece's focus position without the
diagonal.
Image Orientation
The star diagonal reverses the image from left-to-right. This rever-
sal is hardly noticeable when viewing the night sky. If you are
printing star maps on your computer, you may want to have your
program flip the star map to match your eyepiece's reversed view
through the diagonal.
Use of Filters
The 1.25" diagonal is threaded to accept Orion 1.25" filters on its
barrel. If you use filters directly on the star diagonal, it will prevent
having to remove and reinstall filters when switching eyepieces.
The 2" diagonal will also accept filters (Orion 2" size only), either
on the barrel of the diagonal itself or on the bottom of the 1.25"
eyepiece adapter.
Care and Maintenance
Although the star diagonal is quite durable, it should avoid pro-
longed, unnecessary exposure to the elements. Keep the diago-
nal capped on both ends when not in use, preferably in a foam-
lined eyepiece case. It is also recommended to leave the diagonal
in a dry place with caps off overnight to let it completely dry out
after use. Store the instrument in a cool, dry place; storage in a
humid environment can result in degradation of the optical coat-
ings on the mirror. This is not covered by the warranty.
Corporate Offices: 89 Hangar Way, Watsonville CA 95076 - USA
Toll Free USA & Canada: (800) 447-1001
International: +1(831) 763-7000
Customer Support: support@telescope.com
Brass compression ring
Thumbscrew
IN 278 Rev B 01/09