Went out last night to image with a red cat 51/asi 294 mc pro and l-enhance filter. It was around 10 degrees Fahrenheit with fairly high humidity/frost. I went through polar alignment/star alignment with no issues but began experiencing a problem when I got to frame and focus in SGP. Every time I would focus my alignment star (capella) it would go out of focus (get bigger) immediately with each 2 second refresh. After about 15 minutes I gave up. I was using a dew heater on the main lens. I was imaging with this same setup the night before with similar conditions although not quite as cold. Has anybody had a similar experience? I am guessing moisture/frost in the imaging train (on the camera sensor or the l-enhance filter) may have been the culprit but am not sure.
Frame and focus problems
Engaging
Not familiar with how stiff the RC51 is but perhaps something was pulling on the focusing ring? For example if a dew strap is tight on the ring a cable drag can rotate it while tracking causing focus to move like this… May be some other possible explanations…
Thanks for your reply Jonathan. I checked the dew strap last night at the time I was having focus issues and I don’t believe that was the problem.
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Do you think it is possible your scope was still cooling down while you were trying to focus? In other words, it had not reached thermal-stabilization? From my optical days, I still set my stuff up and then let it sit for an hour or so after polar alignment.
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Thanks for your reply Corrales Ray. I left the scope out for about an hour prior to starting polar alignment. Perhaps I did not wait long enough. They are forecasting clear skies on Friday and I will see if there is a reoccurrence.
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Whilst it does sound like something might be slipping, I'd suggest you post your issue up on the SGP forum, if you've not already done so. They have recently changed the focus routine in SGP and a few folks have had issues. The newest stable (non-Beta) version includes this routine.
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