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Last night was great for testing. I had a couple of hours before clouds rolled in from the west and there was also a thin moon crescent to play with.
I had used the TAK scope the previous day to finish collimating the cassegrain focus. It's very close but still needs a tiny more tweaking which I'll do with the artificial star. I spent some time on the moon visually from 32mm to 24, 9, 6 and 4mm eyepiece. I could still easily snap to focus with the 4mm eyepiece and see some very nice sharp details. A lot more than with the C11. I took a couple of shots with my SONY NEX-5 and ZWO ASI 120MM.
Then I switched to the newtonian side which was a bit of a disaster. Visually the focus point snaps and the image is very sharp as well. The fov is huge. On closer inspection at higher magnification I can see very obvious astigmatism so the detective work is starting. I suspect something to do with the secondary as the primary is ok in cassegrain mode. There is an aluminum cylinder that encases the secondary glass to stop it from dewing up I assume. It was very tight so I've losen that. I think maybe it was pressing against the glass. The astigmatism can be compounded by the fact I still haven't got the newtonian side collimated correctly. But there is definitely some kind of stress in the glass there.
Here' s a couple of shots of the primary collimation push/pull system, centering and locking mechanism. It's well designed and very simple.
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