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)
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.
Focuser rotation lock thumbscrew
Threaded holes for
finder scope dovetail base (ED102T CF)
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
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