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It appears that a large proportion of GSO dobs are shipped from the factory suffering from astigmatism due to either or both secondary and primary mirrors being flexed by being too tight in their holders.
Mine, Dave47Tuc, Icemans and Migs GSO dobs all had this issue.
If you dont get nice circular rings on a startest, and nice tight round stars when in focus its well worth the effort of checking the the mounting of both mirrors and ensuring they are not pinched in their holders.
Im a bit dissapointed Bintel didnt pick these issues up for Mike and Dave.
Mike I'll get a howto on this out this weekend if Im not made to work again.
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