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reducer/corrector

Started by hankbuck, 12/17/2003 07:44AM
Posted 12/17/2003 07:44AM Opening Post
I recently purchased a Celestron reducer/corrector and installed it on the back of my 9.25. I couldn't get near to acheiving focus with my Williams Optics Crayford focuser. I kind of expected that. But when I removed it and merely used the reducer, a Televue SCT adaptor, and my Televue 2" diagonal I just barely reached focus with any of my eyepieces. The focuser knob was cranked nearly all the way in one direction with no ability to reach the other side of focus. As much as I like the big views, I feel something isn't right. Any thoughts?
Posted 12/17/2003 09:59AM #1
David,

When using the WO Crayford focuser, you must first place the focus tube at the half-way point. Then do a rough focus with the regular 9.25 focus knob. The WO focuser is subsequently used for fine focus only.

Each time you change eyepieces you will probably have to repeat this process. The Crayford focuser only has about 3/4" of travel and was never meant to handle the total range of focus possibilities. It was built just for fine focus and to avoid mirror shift problems particular to SCT's.

The reducer/corrector is not part of the problem.