Quote:
Originally Posted by codemonkey
Made some progress... after correcting the spacing of the coma corrector, the star shaped improved some... still definitely not close to good enough, but better. At that point I could see very obvious tilt -- stars in focus in the center, round donuts in one corner.
I rotated the camera in the OAG and the tilt moved relative to the camera sensor, so the tilt is before the OAG... I'm thinking the focuser now.
I've been waiting on a 2" drawtube extension so that I could get the autocollimator close to the focal plane and verify collimation. That arrived today and I think I have it collimated now. Unfortunately my secondary was spotted when I got it and I didn't remove it, so it's pretty hard to tell when looking through the central pupil because I have a fuzzy donut of the secondary spot overlaying the radioactive symbol that is the primary spot. In the offset pupil I have two circles though (comprised of the two sets of opposing radioactive symbols).
Interestingly, the Moonlite focuser can be rotated relative to its base... if I do that while looking through the offset pupil, the circles unstack, until I rotate it back to the position at which I collimated it. I'm guessing this confirms that the focuser is not square. I guess it means I'll have to recollimate the scope if I rotate the focuser... which I need to do to compose my images.
Fingers crossed the dark sky tonight shows me pinpoint stars, but I have the feeling I'll be seeing more donuts...
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Lee, I think you might need to check the tilt adjustment on the Moonlite. I found that mine was way out and when I rotated it the laser I was using would form a rather large circle on the primary. Sorting that will ensure you focuser is square to the optical axis. Then you can collimate from there.