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Re: HELP! 20" Obsession Classic F5
¿ªÔÆÌåÓýChuck, I have the same scope as you, Obsession 20¡± F/5, except that my focal ratio is actually 4.92 and my scope and mirror were made in 1999.? I have had them since new.? ? Your focal length is another factor in the pole length required.? What is your mirror focal ratio?? It should be marked on the rear of the mirror, or maybe on the edge.? I¡¯ll check mine here and let you know the length of my poles.? You can compare.? By the way, I have Naglers from 5mm up through a 35mm Panoptic.? I also have an Explorer Scientific 14mm 100 degree EP.? All come to focus. ? Double check proper seating of the poles inside your blocks and proper seating of the poles inside the aluminum clamps at the top. I also concur with the others¡¯ remarks about the collimation screws position, but you have adjusted that already. Has something gone awry in the mirror cell supports?? Perhaps occurring during vehicle transit.? ? If you do go through with cutting your poles, I recommend a large tubing cutter, available a Lowes and Home Depot. However, before I would cut them, I would try to understand what has changed since 2007 to require them to be cut. ?Presumably prior owners had no major issues, but maybe they had different eyepieces.? Measure twice, cut once, of course, but first know ¡°the rest of the story¡±. ? Good luck. ? Charlie ? From: [email protected] <[email protected]> On Behalf Of charles jagow
Sent: Tuesday, July 20, 2021 9:20 AM To: [email protected] Subject: Re: [ObsessionUsers] HELP! 20" Obsession Classic F5 ? Thank you for your help.? The previous owner contacted me after I had put the scope to bed last night.? He had the same problem, but he said he moved the mirror up via the collimation bolts such that his eyepieces (ETHOS) would come to focus.? I moved the mirror up with the collimation bolts to the point I could only see three threads of travel left on each.? I then re-collimated first with the Howie Glatter and then dialed it in with a visual Cat's Eye tool set.? This allowed my Nagler 17mm to pass through focus, allowing me to focus that eyepiece.? The seeing and transparency was horrible last night, but the view of Jupiter was very well defined with the Nagler 17.? Stars are well formed, a little comet shaped much closer to the edge.? The mirror combination is exponentially better than the Ostahowski mirror in my UC 18. |