I don't post on CN because I believe it's an exercise in total frustration as exemplified by the following thread:
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5728122/page/0/view/collapsed/sb/5/o/all/fpart/1
Here we have a case wherein an amateur buys a new optical tube assembly and, as evidenced by his initial post, immediately dissembles it without trying it. As can be seen, he and his accomplice supposedly determine the factory supplied collimation center spotting is faulty, again without trying it first, remove it, replace it with their own, and then experience gross errors of collimation such as double-images.
Meanwhile, another amateur chimes in with a post about his same optical tube assembly that evidently worked as designed without any modifications. Also at that time, my post was met with a response that essentially stated the double images had somehow miraculously disappeared(since there's no explanation of how or why that might have happened)and the severe astigmatism that occurred is now the primary concern. The poster offers up explanations of warped secondary holders and the like for his perceived problems but still has not provided any conclusive evidence regarding the cause of his problem. Astigmatism may certainly be introduced by a faulty secondary and that's not that difficult to diagnose. Additionally, according to the poster, the mirror size of the primary was off, the bevel was wrong and anything he measured, assuming he did so before he messed with it, indicated a gross error with the factory center-spotting. Nevertheless, when he tried to fix it, he got double images that subsequently somehow disappeared(after he was called on it)and now can't figure out how to diagnose the cause of astigmatism despite added links from other posters on how to do it.
I suppose the best case-scenario here will be he'll eventually get some sort of an acceptable image. The worst case will be the vendor that sold the scope to him won't take it back because he messed with it, and in doing so, voided the factory warranty. I also suspect some other vendor might be more than happy to test the secondary and primary, determine a problem and refigure everything, at considerable cost. Of course, nobody would know how the scope might have performed when it was new, because it had never been under the stars when it arrived...
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5728122/page/0/view/collapsed/sb/5/o/all/fpart/1
Here we have a case wherein an amateur buys a new optical tube assembly and, as evidenced by his initial post, immediately dissembles it without trying it. As can be seen, he and his accomplice supposedly determine the factory supplied collimation center spotting is faulty, again without trying it first, remove it, replace it with their own, and then experience gross errors of collimation such as double-images.
Meanwhile, another amateur chimes in with a post about his same optical tube assembly that evidently worked as designed without any modifications. Also at that time, my post was met with a response that essentially stated the double images had somehow miraculously disappeared(since there's no explanation of how or why that might have happened)and the severe astigmatism that occurred is now the primary concern. The poster offers up explanations of warped secondary holders and the like for his perceived problems but still has not provided any conclusive evidence regarding the cause of his problem. Astigmatism may certainly be introduced by a faulty secondary and that's not that difficult to diagnose. Additionally, according to the poster, the mirror size of the primary was off, the bevel was wrong and anything he measured, assuming he did so before he messed with it, indicated a gross error with the factory center-spotting. Nevertheless, when he tried to fix it, he got double images that subsequently somehow disappeared(after he was called on it)and now can't figure out how to diagnose the cause of astigmatism despite added links from other posters on how to do it.
I suppose the best case-scenario here will be he'll eventually get some sort of an acceptable image. The worst case will be the vendor that sold the scope to him won't take it back because he messed with it, and in doing so, voided the factory warranty. I also suspect some other vendor might be more than happy to test the secondary and primary, determine a problem and refigure everything, at considerable cost. Of course, nobody would know how the scope might have performed when it was new, because it had never been under the stars when it arrived...
If you want to read some real top-shelf genuine BS check out an ultra high-end audio forum. (Or maybe the politics forum downstairs... 
)