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Guiding woes
I would be grateful if anyone has an idea or so why I am getting poor guiding in DEC only. Paramount MX with a DSI RC10C firmly clamped. Imager is a QSI 683wsg with an SBIG ST-i guider (built in shutter). My Polar alignment is excellent according to the TPoint model and I use CCDSoft as both imager and guider. I took 25 x 600 sec. images last night and all of them have oval stars, some worse than others, with the long axis in the DEC direction. CCDSoft guiding calibrated fine and the X axis was reasonably stable, varying about 0.6 pixel pp. (ST-i pixels of course) but the Y axis error wandered in excess of 4 pixels pp. The effect was as if the MX has backlash in the DEC axis so I ask is this possible? And if so, does anyone know how to test it so I can ask Bisque how to fix it? Thanks.
Charles
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