Jump to content


CGEM 11 for astrophotography? Anybody doing it?

  • Please log in to reply
8 replies to this topic

#1 Jeff Smith

Jeff Smith

    Viking 1

  • -----
  • Posts: 501
  • Joined: 06 Apr 2010
  • Loc: Chicago

Posted 23 November 2012 - 12:26 PM

Ok, right up front I'll admit that I have done extensive research on the net regarding the use of a C11 to do AP on a CGEM and have found that most people think the C9.25 is more appropriate. The problem is that most of the people that say this do not own/use the C11/Cgem combo for AP.
What I'm looking for is first hand experience from C11/Cgem owners. Good or bad...
I can get a C9.25 OTA for just over $1200 or a C11 OTA for just under $1700. I would love the extra 1.75" but not at the expense of nightly frustration.
I do plan on adding a TPI tripod spreader assembly ( http://www.tpiastro.com/spreaders.htm )to my CGEM either way to improve stability. I have "heard" (no first hand experience)that it will improve the mounts capacity to over 50 lbs. With the spreader, proper balancing and short tripod legs is this dream a possibility or craziness?
With a C11, camera, guidescope and dewshield I'm looking at around 32-34 lbs of equipment.
Anybody having success with a CGEM/C11 in AP?

Thanks in advance and clear skies :-)

#2 Jeff Smith

Jeff Smith

    Viking 1

  • -----
  • Posts: 501
  • Joined: 06 Apr 2010
  • Loc: Chicago

Posted 23 November 2012 - 12:52 PM

I forgot to mention I plan on doing a lot of visual work with whatever scope I get.

#3 Jeff Smith

Jeff Smith

    Viking 1

  • -----
  • Posts: 501
  • Joined: 06 Apr 2010
  • Loc: Chicago

Posted 23 November 2012 - 06:51 PM

55 views and no one can say that they are successful at AP with a C11 on a CGEM.
I'll start looking for a good new or used C9.25. I had a feeling...

Clear Skies :-)

#4 ewave



  • *****
  • Posts: 1282
  • Joined: 16 May 2009
  • Loc: northwest NJ

Posted 23 November 2012 - 07:49 PM


All I can say is I have a CGEM with the C9 and I think this would be the limit at least if you want to shoot DSO's. Although I piggyback my 7 lb APO on top of the C9, once a while the gears start slipping if you dont tighten the locks on the mount. This would be approximately the weight of a C11 if you catch my drift.

#5 herrindude


    Ranger 4

  • -----
  • Posts: 311
  • Joined: 25 Jul 2010
  • Loc: Fairhope Alabama

Posted 23 November 2012 - 11:37 PM

I use my c11 on an older cge mount and could probably do more,but I'm content with the c11. I have read here on cloudy nights of people using this combo, but everything has to be just right. It is much better to over mount than to under mount, but i know the cge pro is very expensive, just my 2 cents.

#6 EFT


    Vendor - Deep Space Products

  • *****
  • Vendors
  • Posts: 2602
  • Joined: 07 May 2007
  • Loc: Phoenix, AZ

Posted 24 November 2012 - 11:45 AM

I forgot to mention I plan on doing a lot of visual work with whatever scope I get.

You would be OK for visual work but would want to add a motorized focuser.

Here's my answer from the Yahoo group.

The first thing I would ask is, what is your AP experience level? Assuming that you are not planning on HyperStar, if you have a lot of experience with AP and with mount and setup tweaking, then the combination might be OK for you. You would need to plan on tuning the mount, since it will need to be working at its best for this load.

I do have this combination, but do not use it for imaging. I personally feel that the CGEM stuggles with it, even when tuned and balanced. The CGEM DX does better because the DX motor board seems to run the motors smoother.

I don't recommend the combination because I have spoken with too many people who have bought this combination only to end up selling it out of frustration. If you really want it, then there are steps you can take to help yourself out.
First, tune the mount. Second, start by using a HyperStar. Third, after mastering HyperStar, move to prime focus with a focal reducer. Finally, if you have mastered these, then try prime focus AP.

#7 Raginar


    Fly Me to the Moon

  • *****
  • Posts: 6138
  • Joined: 19 Oct 2010
  • Loc: Rapid CIty, SD

Posted 24 November 2012 - 01:22 PM

I put a 10" Meade SCT on a CGEM; I was not happy with the AP I was able to pull out of it. It was very delicate to balance and it definitely 'maxxed' out the mount. I'd say a 9.25" is better fit or even a 8".

Good luck!

#8 WarmWeatherGuy


    Surveyor 1

  • *****
  • Posts: 1953
  • Joined: 27 Aug 2011
  • Loc: Orlando, FL 28° N, 81° W

Posted 24 November 2012 - 10:03 PM

I have a CGEM with a C8 and a C11. I use my C8 for guided astrophotography. My equipment weighs 30 pounds with the C8 so it would weigh 43 pounds with the C11. I actually tried to mount it all and I found I need to buy another counterweight.

I plan on using the C11 for imaging the planets and Moon, unguided.

If you are only going to have one OTA for astrophotography I would recommend a much shorter focal length. You actually need a small collection of different scopes for the different things in the sky. The C11 would be one of the last ones to get unless you were primarily interested in the planets. I would start with the C6, C8, or an APO refractor.

#9 Jeff Smith

Jeff Smith

    Viking 1

  • -----
  • Posts: 501
  • Joined: 06 Apr 2010
  • Loc: Chicago

Posted 24 November 2012 - 11:15 PM

Wow, great responses. I really appreciate the help here and on the CGeM Yahoo group. This was a tough decision and I didn't want to make an impulse buy. I have owned a C11 and a CGEM but never at the same time. I loved them both but don't want the frustration. I think I'll look for an Edge HD 800 OTA.
Thanks again guys.


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics