2
Congratulations on your purchase of an Orion f/3.9 Newtonian Astrograph! These powerful imaging
telescopes feature “fast,” high-quality parabolic optics, a 2" dual-speed Crayford focuser, and excellent
mechanical construction with some special features. Optimized for astrophotography with DSLR and
astronomical CCD imaging cameras, our f/3.9 Newtonian Astrographs are capable of delivering breathtak-
ing imaging performance – for beginning to advanced astrophotographers.
This instruction manual covers both the 8" and 10" mod-
els of f/3.9 Newtonian astrograph. Although they differ
in aperture and focal length, physical size, and weight,
they are otherwise very similar in mechanical construc-
tion and features. So we will use the 8" model to illus-
trate the features of both astrographs. Any exceptions
related to the 10" model will be noted.
This instruction manual will help you to set up and
properly use your telescope. Please read it through
completely before attempting to use the scope and its
included accessories
.
Parts List
• Optical tube assembly
• Optical tube dust cap
• 1.25" eyepiece holder
• 9x50 finder scope with bracket
• Pair of hinged tube rings
• 2" thread-on extension adapter, 30mm
• 2" slip-on extrension adapter, 36mm
• Quick collimation cap
• Cooling accelerator fan and battery holder (batteries not
included)
• Starry Night Special Edition CD-ROM and StarTheater
DVD
We recommend keeping all of the original packaging. In the
unlikely event you should need to ship the telescope back to
Orion for warranty repair service, you should use the original
Optical
tube
Tube rings
Fine focus wheel
Focus
wheel
Focus wheel
Drawtube
tensioning
thumbscrew
9x50 Finder
Scope
Finder scope
bracket
2"
Accessory
collar
WARNING: Never look directly at the Sun through your
telescope or its finder scope – even for an instant – with
out a professionally made solar filter that completely cov
ers the front of the instrument, or permanent eye damage
could result. Young children should use this telescope
only with adult supervision.
Figure 1.
The Orion 8" f/3.9 Newtonian Astrograph
