Bear with me, it's complicated. I was imaging with a C11, .63X reducer flattener, NBZ filter and an ASI183MC Pro camera. It was on a CQ-350 mount, with ASIAIR+ and EAF focuser. Guiding was with the Orion 80mm short tube (fl 400mm) with the ASI178MC camera. I was imaging M82 and shot 165 frames at 120secs, 111gain (unity), Bin1, -10C. I did polar align and ran the autofocus routine before starting. My guiding graph was excellent with Total RMS never reaching higher that .9 arc secs and sometimes as low as .3 arc secs. One thing different was that the PHD calibration wanted to use a star at the very edge of the screen. I selected a single star, so I wasn't using the multi-star calibration. I thought of going back to it but my guiding seemed excellent so I didn't mess with it. My images looked good but a couple of time I noticed that my images would move, slowly but steadily, in one direction for awhile (as if tracking had stopped). Then suddenly it would go back. The guiding graph would still look good and the images would look good. I thought this might cause me to lose some frames but it wasn't until I downloaded and Blinked the images that I realized that this had happened more than I thought (mostly it was horizontal but some events were vertical). When I tried to calibrate and stack the images (in Pixinsight) most of them failed to register.
Any ideas as to what could have caused the movement to occur in the first place? I am totally at loss for this, according to guiding graph it never should have happened.
Any ideas as to what could have caused the movement to occur in the first place? I am totally at loss for this, according to guiding graph it never should have happened.
