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Celestron 9.25 and Orion Sirius Mount

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#1 myshkin

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Posted 07 June 2013 - 03:53 AM

I am looking to buy used a celestron 9.25 XLT OTA and a Orion Sirius Mount. The 9.25 is set for CGE.
What would I need to make this pair work?

The mount is rated for 30lbs and the ota is 20lbs. With my Nikon D800 I figure I will be pushing it close but not over. I noticed sites sell the 9.25 with the AVX and CG-5 mounts which have a 30lb limit as well so I am hoping this setup will work for AP

#2 Raginar

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Posted 08 June 2013 - 09:54 AM

Most people will tell you no. Some will say it'll work just fine. The answer is it depends :)

I tried to max out my CGEM and it was not 'fun' to image with. If AP is your goal I would get a widefield refractor and a CG-5. Once you learn short focal length AP, you can consider jumping up to long focal lengths.

#3 Phil Sherman

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Posted 08 June 2013 - 08:34 PM

I was able to image with an 8" f/5 Newt on a Sirius with reasonable success at 25lbs. When I hit 30, I upgraded the mount to an Atlas.

You're going to need to carefully balance everything and will probably need vibration damping pads for the tripod legs. An electric focuser will eliminate touching the scope and causing vibrations when focusing.

Phil

#4 orlyandico

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Posted 09 June 2013 - 01:49 AM

thing is an 8" f5 newt has a focal length of 40 inches.. 1 meter.

a C9.25 has a focal length of 2.35 meters. more than double. so everything will have to be 2.35X more accurate, etc.

my experience.. don't even try it. a CGEM is marginal for a C9.25 at native FL.

#5 myshkin

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Posted 09 June 2013 - 09:27 PM

I was planning to get the hyperstar for the 9.25 to shorten the exposure time.

#6 calder

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Posted 09 June 2013 - 10:58 PM

Hi, if your buying used make sure the 9.25 your looking at is Fastar/hyperstar compatible. Most if not all (to the best of my knowledge) pre-Edge 9.25 scopes are not Fastar compatible. That's a lot of weight for a Sirius mount.
I have both a 9.25 and the Sirius mount and you will have to make sure it's really well balanced. I use this setup for visual only.
Good luck,
Bob

#7 orlyandico

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Posted 10 June 2013 - 12:15 AM

There are some fastar compatible non EDGE c9.25s

But most aren't. So be careful.

Also the cost of the Hyper star and conversion kit is way more than the cost of the C9.25 itself.

But yes a Sirius will work fine that way. You're only talking about 470mm focal length.

#8 myshkin

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Posted 10 June 2013 - 03:38 PM

The 9.25 I bought is has never been used and has the fastar on the front. Thanks everyone for the feedback. Maybe I should consider another mount

#9 neptun2

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Posted 30 June 2013 - 08:52 PM

Well i used 8" f5 newtonian on heq5 pro also and agree that for focal length around 1000 to 1150 mm you should not put more than 25 lbs on heq5 pro and you should balance very well to achieve reasonable results. For pure c9.25 with it's long focal length i would say that you should get better mount. With fastar it should work well.






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