Joe, if the stars are round, but soft, it's a focus problem. Critical focusing can be very difficult, and actually changes as temperatures drop. Especially at higher image scales. Also look at the ground you set-up on. A portable telescope can "settle" over time, sometimes imperceptably- until you critically examine the shot itself. So polar-alignment is thrown off, and a tracking error is introduced that can be maddeningly hard to pin-down, since it has nothing to do with the hardware, software, or operator. Even spreading-out the weight over a larger area with plywood pads, for example, might not help. --- Joe Bauman <bau@desnews.com> wrote:
Actually, in looking at the photo, I'm not sure what caused the problem. I had an awful time getting it aligned that night, so maybe it's just off polar alignment. Maybe there is a little tracking error. Or perhaps there is some squishiness because of optics. Possible causes of the optics making stars less round, I think, are that the telescope was not as well colliminated as I'd thought, the focal reducer wasn't working as well as it should, or both. More to think about. -- Thanks, Joe
__________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com