Celestron 11 inch OTA Pros and Cons ???
Posted 31 March 2013 - 10:09 AM
Posted 31 March 2013 - 12:48 PM
-- Excellent aperture,a sweet spot in my opinion that opens up a lot of objects visualy that 8 inches and lower will struggle to get like the E & F stars in the trapezium, the M51 bridge, etc.
-- Holds collimation very well.
-- Kind to most eyepieces.
-- Excellent for binoviewing.
-- Big and weighty enough to resist wind and vibration.
-- Hefty, not a struggle to transport and mount, but not for those with bad backs or other disabilities.
-- Because of its higher resolution, is also somewhat sensitive to poor seeing.
-- Cooldown time . . . not a grab and go by any means.
I would say if you are considering a lot of AP, the 9.25 Edge would be superior. If mostly visual, the 11.
Posted 31 March 2013 - 01:29 PM
i had a nexstar 11 once (around 2005-2007) and a cpc9.25 now. what i notice is a better, sharper performance and more contrast. you have to consider that the 9.25 is not just an sc between the 8" and 11" aperture but has a longer focal length than those both. some users say the 9.25 comes close to a maksutov sc in performance.
just my two cents here...
Posted 31 March 2013 - 07:56 PM
Posted 31 March 2013 - 08:03 PM
Posted 01 April 2013 - 02:45 AM
wasn´t able to explain in english. i try again: the 9.25 tube has the same length as the 11" but less aperture (what is pretty obvious).
the size of the secondary mirror and the extension factor definitely differ from 8 and 11" SCs. seems, these features make it a very special cpc and the 9.25 is not just an "in between" scope though.
Posted 01 April 2013 - 09:18 AM
Looking at getting a Celestron 11in OTA with Starbright XLT mutlicoatings. In this area I do not know anyone with this scope to see how they rate the performance. I was thinking of the 9.25 edge to possibly do some DSLR photography maybe down the road not sure. I also know aperture rules. Would like to have any pros and cons on this 11 inch OTA on its all around performance. Thank you
What do you want to image? Unless it is small targets, stick with a C8. Less expensive, more field, less focal length. All the C11 buys you for imaging is more focal length and image scale.
The C11 is a fine scope for visual use with there being an obvious difference between it and the C9.25 visually.
Posted 01 April 2013 - 10:37 AM
Posted 08 April 2013 - 08:29 PM
Posted 08 April 2013 - 10:52 PM
Posted 09 April 2013 - 05:21 PM
I do not consider myself an expert but this has been my experience.
Posted 10 April 2013 - 11:37 AM
However, the overall package was extremely heavy and clumsy to move around. So, I have now deforked the OTA and have it on a the Celestron version of a Losmandy dovetail. In this mode, it is surprisingly light and easy to move around, and easily goes on my Mach 1 GTO.
My least favorite modes have all be visual and native photography, since the coma is rather severe. I have gotten the Starizona SCT reducer/ flattener, but haven't had a chance to try it out- this has been a winter of very bad seeing, here abouts.
The hyperstar mode has some drawbacks, namely you have to replace the secondary after mount alignment. In my case, I have been getting an unusual internal flare sometimes on bright stars which produces a pure blue "pseudo nebula" artifact. I haven't been able to track down if anyone else has that. On that note, I see I have a post to make in the Cats and Casses forum.
The reason I'm not so hot on it for visual is I just never seem to be able to get one of the really good images from this scope. Maybe it's the desert always outrunning its cooldown, or what. I do better with my C8 consistently. At the moment, if it weren't for hyperstar I'd list it for sale immediately without a second thought.
Posted 10 April 2013 - 12:02 PM
I remember better looking views from the C11 mounted in the dome at the PAS observing site.
My AP 130 EDFGT, a full 150mm smaller in aperture, doesn't take it to school; it's more like a gangland assassination.
Posted 10 April 2013 - 12:21 PM
Posted 10 April 2013 - 11:11 PM
Posted 11 April 2013 - 12:39 AM
Posted 11 April 2013 - 12:43 AM
Posted 11 April 2013 - 09:57 AM
Posted 11 April 2013 - 10:01 AM
Posted 11 April 2013 - 11:32 AM
Posted 11 April 2013 - 03:26 PM
Posted 11 April 2013 - 07:13 PM
Posted 11 April 2013 - 07:51 PM
The older Meade 12' had a hyperstar version. The ACFs don't, so C11 or Edge HD 11 is basically the only game in town these days.
My understanding is the Edge HDs are a totally different critter- they're all ostensibly perfect. Of course, that doesn't make much difference for hyperstar, since it bypasses the internal flattener in the baffle tube.
I've sent in my picture of the hyperstar nebula to Dean at Starizona to see if he's seen it previously.