Orion STARMAX 9541 - Manual (Page 13)

13
Specifications
#9549 GoScope 80 TableTop
Optical design
Refractor
Objective lens Achromatic, air-spaced, fully
coated
Aperture 80mm
Focal length 350mm
Focal ratio f/4.3
Diagonal 90° prism, accepts 1.25"
eyepieces
Eyepieces 20mm eyepiece (18x) and
10mm eyepiece (35x), fully
coated, 1.25"
Finder scope EZ Finder II reflex sight
Optical tube mounting block Fits Orion Dovetail mounts
and ¼"-20 photo tripods
Total weight 5.7 lbs. (tube 2.9 lbs, mount
2.8 lbs)
#9909 StarMax 90 TableTop
Optical design
Maksutov-Cassegrain
Primary mirror coating Aluminum with SiO
2
overcoat
Meniscus lens coating Anti-reflection multi-coatings
on both sides of lens
Aperture 90mm
Focal length 1250mm
Focal ratio f/13.9
Central obstruction diameter 29mm
Eyepiece adapter
Accepts 1.25" accessories,
camera T-threads
Diagonal 90° mirror star diagonal, 1.25"
Eyepieces 25mm (50x) and 10mm
(125x), fully coated
Finder scope EZ Finder II reflex sight
Optical tube mounting block Fits Orion Dovetail mounts
and ¼"-20 photo tripods
Weight 6.5 lbs (tube 3.7 lbs, mount
2.8 lbs)
#9541 SkyScanner 100 TableTop
Optical design
Reflector
Primary mirror Parabolic
Primary mirror coating Aluminum with SiO2 overcoat
Secondary mirror diameter
Aperture
100mm
Focal length 400mm
Focal ratio f/4
Focuser 1.25" Rack & Pinion
Eyepieces 20mm (20x) and 10mm (40x)
fully coated
Finder scope EZ Finder II reflex sight
Optical tube mounting block Fits Orion Dovetail mounts
and ¼"-20 photo tripods
Weight 6.2 lbs (tube 3.4 lbs, mount
2.8 lbs)
Appendix A: Collimating
(Aligning the Mirrors)
Collimating is the process of adjusting the mirrors so they are
perfectly aligned with one another. Your telescope’s optics
were aligned at the factory, and should not need much adjust-
ment unless the telescope is handled roughly. It is only rec-
ommended you make changes if the telescope is grossly out
of alignment. Slight variations should still provide acceptable
viewing under most conditions.
To check collimation (mirror alignment), remove the eyepiece
and look down the focuser. You should see the secondary
mirror centered in the drawtube, as well as the reflection of
the primary mirror centered in the secondary mirror, and the
reflection of the secondary mirror (and your eye) centered in
the reflection of the primary mirror, as in.
Star-Testing the Telescope
When it is dark, point the telescope at a bright star and accu-
rately center it in the eyepiece’s field of view. Slowly de-focus
the image with the focusing knob. If the telescope is correctly
collimated, the expanding disk should be a perfect circle. If
the image is unsymmetrical, the scope is out of collimation.
The dark shadow cast by the secondary mirror should appear
in the very center of the out-of-focus circle, like the hole in a
donut. If the “hole” appears off-center, the telescope is out of
collimation.
NOTE: If you try the star test and the bright star you have
selected is not accurately centered in the eyepiece, the
optics will always appear out of collimation, even though
they may be perfectly aligned. It is critical to keep the star
centered, so over time you will need to make slight cor-
rections to the telescope’s position in order to account
for the sky’s apparent motion.