Re: An easier Pasillx N & S Polar Alignment method
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Roland Christen
I would have started by aligning the finder to the OTA using an
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"illuminated cross hair eyepiece", until these two were parallel, and then go through your procedure to make the OTA/finder orthogonal with the mount, and then also polar aligned. It would have taken me all night to get the tube assembly perfectly orthogonal. I din't care to do that. My main mission was to get the mount POLAR ALIGNED. For that, having a scope with orthogonal crosshairs makes the job very easy. That scope was the finder. You may not understand this, but the mount is always orthogonal. It is the main scope that can be off for various reasons. In the case of an SCT for instance, just collimating the secondary mirror throws off the scope orthogonality. Therefore, it is not always possible to get the main scope to always be dead nuts on. I don't need it to be dead nuts on. I did not need it to do my polar alignment. I just needed a scope, any scope, to be orthogonal to the mount. The finder was the perfect choice because it is soooo easy to adjust the orthogonality. For finding things later on with the main scope, it does not need to be perfectly on. It's close enough that all object always appear somewhere in the CCD field. Comprende vous? Rolando -----Original Message-----
From: Joseph Zeglinski <J.Zeglinski@...> To: ap-gto@... Sent: Sat, 20 Sep 2008 1:02 pm Subject: [ap-gto] Re: An easier Pasillx N & S Polar Alignment method Hi Rolando, I too was a bit confused, but let that slip. Now I am really confused. I understand your method and the explanation is clear, but I don't get the "initial conditions". Was the main OTA (with finder on top), already perfectly orthogonal to the mount, or is the finder physically attached to the AP-3200 mount, and therefore requires its own alignment? Even with the latter, adjusting the mount Alt-Az knobs for the finder, ruins the OTA derived mount alignment. Saying: * ****** The advantage of using the 8x50 finder was that i could quickly adjust it via the thumbscrews to be perfectly orthogonal to the mount (unlike the Big Mak which was off about 15 arc minutes). ****** ... implies that this was an "initial installation", and the finder and OTA were not yet aligned to each other. I would have started by aligning the finder to the OTA using an "illuminated cross hair eyepiece", until these two were parallel, and then go through your procedure to make the OTA/finder orthogonal with the mount, and then also polar aligned. The way I read this, you are making the (OTA attached) finder orthogonal to the mount, and once completed, you then need to repeat for the main OTA - which now misaligns the finder. The only way this explanation would seem right to me - is if you had said that the OTA was already previously orthogonal to the mount, and the procedure was merely to do the same for the finder. But that is a harder way to do that than using a cross hair eyepiece in the first place. The only saving is the purchase of that special eyepiece, which I assume most of us already own. Thanks for a further clarification. Joe ----- Original Message ----- From: <chris1011@...> To: <ap-gto@...> Sent: Saturday, September 20, 2008 11:54 AM Subject: Re: [ap-gto] Re: An easier Pasillx N & S Polar Alignment method The mount's altitude axis is properly set and the finderscope's adjuster screws are also properlyder is perfectly orthogonal.
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