OFF-AXIS GUIDER INSTRUCTION MANUAL MODEL #93648 TITLE I 1
INTRODUCTION Your Celestron Off-Axis Guider (OAG) allows you to take accurate, long exposure astroimages when used with an autoguider. Since the autoguider and imaging camera share the same telescope, you will achieve tracking accuracy greater than you would with a separate guide scope. PARTS LIST Male M48 Camera Adapter Male M42 T-thread Camera Adapter Medium M48 Spacer Ring (11.55mm) SCT Adapter Long T-thread Spacer Ring (24.25mm) Off-Axis Guider Medium T-thread Spacer Ring (11.
SYSTEM REQUIREMENTS The Off-Axis Guider (OAG) requires a telescope, imaging camera, autoguider, and a mount tracking equatorially with autoguiding capability. You should already be familiar with these items before using the Off-Axis Guider. Refer to Figure 2 to familiarize yourself with the OAG. TELESCOPE To attach the front of the OAG to the telescope, the telescope must have M42 T-threads, M48 threads, or 2” Schmidt-Cassegrain style threads.
CONFIGURING THE OFF-AXIS GUIDER The included adapters allow you to use the Off-Axis Guider with popular combinations of autoguiders, imaging cameras, and telescopes. Some telescopes, like the EdgeHD series, require a specific backfocus distance to the detector on the imaging camera. For this reason, the Spacer Rings must be used to achieve the correct distance. Pick-off Prism Flat Faces Telescope Always position the OAG so that the flat side of the pick-off prism faces the telescope (Figure 3).
CONFIGURATION FOR EDGEHD 925, 1100 AND 1400 TELESCOPES WITH NIGHTSCAPE, DSLR, OR FULL FRAME DSLR OR CCD CAMERAS Refer to Figure 5.1 for APS-C sized camera sensors, such as Celestron Nightscape, Canon Rebels, or other CCD cameras. Refer to Figure 5.2 for full frame (35mm format) cameras such as the Canon 5D or large format CCD cameras.
CONFIGURATION FOR OTHER TELESCOPES, USING A CAMERA ADAPTER Refer to Figure 7 as a possible configuration that uses a camera adapter. Any telescope with a camera adapter that uses T-threads or 48mm threads can attach to the OAG using the supplied female M42 or M48 adapters. Note that you need to supply the camera adapter if your telescope does not already have threads build into the focuser.
FOCUSING Always start by focusing the imaging camera with your telescope. Then, proceed to focus the autoguider using the helical focus adjustment. The first time you use the OAG, you may need to locate a guide star visually with a 1.25” eyepiece. The Moon or a bright star cluster are good targets to start with so you can clearly see something on the camera side and guider side. If the imaging camera does not reach focus, determine if you need more inward or outward focus travel.
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