Orion #8297 8" F/3.9 - Manual (Page 6)

6
Attaching a CCD Camera
The Orion f/3.9 Newtonian Astrographs are equipped to
accept CCD cameras with a 2" nosepiece, or a 2" coma cor-
rector in place of the nosepiece, which slides directly into
the telescope’s focuser like an eyepiece
(Figure 5). The 2"
nosepiece is secured with the two thumbscrew locks. If your
CCD imager does not include a compatible 2" nosepiece, or if
you wish to utilize the camera’s T-threads without a coma cor-
rector, a zero-profile prime focus camera adapter is required
(available from Orion). The zero-profile adapter has male
T-threads that couple to the female T-threads of your camera.
Note that, depending on your CCD camera’s specifications,
you may need to add T-thread spacer rings between the coma
corrector and the CCD camera, to achieve the necessary crit-
ical distance between the coma corrector’s rear lens element
and the camera’s imaging sensor.
Attaching a DSLR Camera
To attach a DSLR camera, you will need the appropriate
T-ring for the make and model of your camera. If you do not
plan to use a coma corrector, then you will need a zero-profile
prime focus camera adapter (available from Orion). Simply
attach the T-ring to the camera body and thread the zero-pro-
file camera adapter into the T-ring. Then insert the barrel of
the camera adapter into the focuser’s 2" accessory collar and
secure it with the two thumbscrew locks
(Figure 6).
To use a coma corrector, thread it into the T-ring attached
to your DSLR camera body, then insert the coma corrector
housing into the focuser through the 2" accessory collar and
tighten the two locking thumbscrews on the collar to secure
the camera in place.
Removing the Piggyback Camera Adapter from
the Tube Ring
If you want to install an optional mounting plate atop the tube
rings for piggyback attachment of a guide scope, you’ll need
to remove the piggyback camera adapter first. To do so, first
remove the tube ring from the telescope. Then unthread the
plastic ring from the threaded bolt. Peel back the felt lining on
the inside surface of the tube ring where the bolt is located;
peel it back just enough so that you can access the bolt head
with a screwdriver. Using a Phillips screwdriver, remove the
bolt from the ring. Now, replace the adhesive felt over the area
where the bolt head was. Now the rings are ready to accom-
modate a mounting plate for your piggyback guide scope
assembly.
The Orion f/3.9 Newtonian Astrographs were designed with a
couple of special enhancements to maximize the contrast of
your astrophotographs and visual images. One is the inclusion
of multiple baffle rings on the interior of the optical tube. The
8" model has 9 baffle rings and the 10" model has 13. These
baffle rings block the transmission of off-axis light through the
optical tube, which could reduce image contrast. The other
contrast-enhancing feature is the extended length of the opti-
Figure 6. Attachment of a DSLR camera requires a T-ring for
the particular camera model and a T-adapter, such as the Orion
Zero-Profile Prime Focus Camera Adapter, which fits into the 2"
accessory collar.
Figure 7. The 1.25" eyepiece holder and two 2" extension
adapters included with the 8" and 10" f/3.9 Newtonian Astrographs.
DSLR camera
Zero-profile
camera
adapter
(not
visible)
T-ring
2"
Accessory
collar
1.25" Eyepiece
holder
2" Slip-on
adapter, 36mm
extension
2" Thread-on
adapter, 30mm
extension
Figure 5. The Orion Parsec 8300 CCD camera, with 2" zero-
profile adapter (nosepiece), which is included with the camera.
2" Nosepiece