Orion ED102T CF Manual page 4

3" Dual-Speed Crayford Focuser For the
ED102T CF
The ED102 T CF features a large 3" format focuser to sup-
port imaging cameras with a greater imaging area. The visual
back of the focuser steps down to a standard 2", however,
the wider opening of the focuser and baffling system of the
ED102T CF yields greater field illumination to support 35mm
or larger format cameras. Additionally, the focuser supports
very heavy payloads such as a large format CCD camera,
filter wheel, and other accessories.
Focuser Rotation
The focuser assembly on the ED T CF refractors have the
ability to be rotated. Under normal use, you should not have
to rotate the focuser, since the eyepiece and diagonal can be
rotated instead. However, focuser rotation can be beneficial for
changing the camera orientation while imaging. Additionally,
this feature can allow you to keep the focus knobs parallel to
the ground no matter how your telescope is positioned.
To rotate the focuser, loosen the focuser rotation lock screw
(Figure 3) counter-clockwise. Gently rotate the focuser to the
desired orientation. Lock the focuser in place by turning the
focus rotation lock ring clockwise. If you find the focuser is
too difficult to rotate, you may have to also loosen the three
socket head screws around the focuser with a 1.5mm hex key
(not included). Leave the three socket head screws with slight
tension, but do no over tighten them.
Using 1.25" and 2" Accessories
Your ED T CF refractor can accommodate both 1.25" and 2"
accessories, including just about any eyepiece, diagonal, or
camera. The Crayford focuser has a 2" eyepiece holder with a
1.25" eyepiece adapter installed (Figure 3). Both the 2" eye-
piece holder and 1.25" eyepiece adapter feature a brass com-
pression ring to hold your accessories in place without mark-
ing them. The telescope must be used with either a diagonal
or extension tube in order for the eyepiece to reach focus. In
most cases, you will be using a 90° star diagonal for visual
use with an eyepiece.
To attach a 1.25" diagonal or extension tube to your telescope:
1. Remove the dust cap from the 1.25" eyepiece adapter.
2. Insert the barrel of your diagonal or extension tube into the
1.25" eyepiece adapter.
3. Secure the barrel in place by firmly tightening the thumb-
screw on the 1.25" eyepiece adapter.
To attach a 2" diagonal or extension tube to your telescope:
1. Loosen the thumbscrews on the focuser's 2" eyepiece
holder and remove the 1.25" eyepiece adapter.
2. Insert the barrel of your diagonal or extension tube into the
2" eyepiece holder.
3. Secure the barrel in place by firmly tightening the thumb-
screws.
4
Focuser
rotation lock
thumbscrew
2" Eyepiece
holder
1.25"
Eyepiece adapter
Figure 3.
Rotatable focuser.
Finder Scope Compatibility
The included finder scope dovetail base on the ED80T CF
is ready to accept any Orion finder scope (Figure 1.1). The
ED102T CF does not include a finder scope dovetail base;
however, it is available optionally from Orion and directly fits
the holes in the ED102T CF (Figure 3).
To insert a finder scope onto your ED T CF refractor, slide
the finder scope bracket into the finder scope dovetail base
and secure it in place by tightening the thumbscrew(s) on the
dovetail base.
Operating the ED T CF
Refractor
Now that you have become familiar with the different features
and functions of your ED T CF refractor, you are ready to
begin using your new telescope outside under a starry night.
The ED T CF refractors are essentially ready to begin observ-
ing with immediately. There is a small period of time where the
internal temperature of the telescope must match the outside
temperature to obtain the best image quality. This only takes a
few minutes. Typically, the ED T CF will have reached outside
temperature by the time the telescope is setup.
Connecting the ED80T CF Tripod or
Telescope Mount
The ED80T CF has a built-in mounting block ready to connect
to a sturdy camera tripod or telescope mount (Figure 1.1).
The mounting block is threaded to accept a common 1/4"-
20 stud found on almost any camera tripod. To connect the
ED80T CF to a camera tripod, simply screw the 1/4"-20 stud
Threaded holes for
finder scope dovetail base
(ED102T CF)