Author Topic: Atlas EQ-G mount with a C11 for astrophotography?  (Read 412 times)

Ralph Gleason

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Atlas EQ-G mount with a C11 for astrophotography?
« on: January 08, 2018, 07:38:23 AM »
Hello All,

I was looking to get a good deal on an Atlas EQ-G mount. I currently have an 8" scope which it will more than handle. I have gotten pretty good images with the 8", but I want to know if it will handle a Meade 10" or C11 for astrophotography in the near future. I would think I'd be pushing the mount somewhat with one of those. I know that there's an unwritten rule to only pack themount with half of the weight of its limit for astrophotography, so 20lbs of equipmenton a mount rated for 40lbs. The Atlas states 40lb payload, and I believe that 33-35 pounds would be a fair estimate with a larger OTA, autoguider and camera. Anyone image with either of those 2 OTAs on an Atlas mount? Is it too much? any input would be appreciated

Regards,
SH1



Michael Thompson

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #1 on: January 09, 2018, 05:46:43 AM »
I've always heard to half the stated capacity of the mount and base your equipment weight on that value for AP.

caenalfosen

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #2 on: January 10, 2018, 07:37:40 AM »
SH1,

 It's probably too much. I use an Atlas EQG with a de-forked Meade 10" SCT OTA for visual. It works well enough but photography is very trying/frustrating even if you have several years experience with other equipment. I used the Atlas with a 102 mm refractor for about five years before mounting the 10" Meade SCT. I used that to practice AP with an SCT for about six months before getting a Celestron EdgeHD 11". I then used the 11" (along with the Celestron EdgeHD 0.7x Focal reducer) on the same Atlas EQG for about 6 months before upgrading my mount. The mount upgrade had been planned in advance of getting the 11". (I had to use 3 counterweights plus a 5 pound barbell to even balance the 11" on the Atlas.) I also had to upgrade the Vixen dovetail saddle of the Atlas with a Losmandy dovetail to handle the extra weight of the SCTs.

 I had been using the Atlas with a 102 mm refractor for about five years before mounting the larger SCTs. Even with the prior AP experience, the weight of either of the SCTs was enough that I had trouble maintaining guiding to the required level for more than 10 minutes at a time. I could image only when there was no hint of wind. Loaded with one of the SCTs, the Atlas would vibrate or sway with each minor breeze.

 This image with the EdgeHD 11" on the Atlas was a real challenge. While it can be done, I would not recommend it unless you have the patience of Job and are a real glutton for punishment and frustration. In addition, if you try using the SCT, you will need to use an off-axis guider. Between "overloading" the mount and the moving mirror of the SCT, you need to use every trick in the book to optimize guiding. The long focal lengths of SCTs are unforgiving on a smaller mount like the Atlas.



 If you have a good background (up to several years) in astrophotography already, you might get passable results under near-perfect conditions from the SCT. You didn't mention your level of experience with astrophotography. It will be very difficult even if you have practiced AP for several years. If you haven't done much astrophotography yet, this is not the configuration to start with. The only AP I would suggest to a beginner with a 10" to 11" SCT on an Atlas is to piggy-back your DSLR with an 85 mm to 100 mm lens onto the SCTs top and start by shooting wide field shots.

 Mounting up to or over 40 pounds on the Atlas will not damage it unless you are VERY much off balance. The mount can physically handle that load just fine and works great for visual astronomy. It's just that the mount and its light-duty tripod are not up to the task of shooting long exposure DSO images in less than perfect conditions which rarely occur in my neck of the country.John

sremburjuni

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #3 on: January 10, 2018, 01:40:52 PM »
Yep too much for that mount for AP.

scolposnimbworr

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #4 on: January 11, 2018, 08:18:59 AM »
All,
Thanks so much for your input. Just bought the Atlas for $700 and picking up tomorrow. jdupton, you're so right about starting small... This will be a perfect AP setup with my 8" and the extras with no issues and plenty of headroom. If I go bigger someday ill get a heavier mount then.... I've gotten some good images, but havea lot to learn before I take on a C11. Great shot by the way!

Thanks for bringing me back down to earth, aperture fever can make you delirious sometimes

Regards,
SH1

unllamerblood

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #5 on: January 12, 2018, 04:48:00 AM »
Quote
Hello All,

I was looking to get a good deal on an Atlas EQ-G mount. I currently have an 8" scope which it will more than handle. I have gotten pretty good images with the 8", but I want to know if it will handle a Meade 10" or C11 for astrophotography in the near future. I would think I'd be pushing the mount somewhat with one of those. I know that there's an unwritten rule to only pack themount with half of the weight of its limit for astrophotography, so 20lbs of equipmenton a mount rated for 40lbs. The Atlas states 40lb payload, and I believe that 33-35 pounds would be a fair estimate with a larger OTA, autoguider and camera. Anyone image with either of those 2 OTAs on an Atlas mount? Is it too much? any input would be appreciated

Regards,
SH1

Well, remember, the C11 won't go any deeper than the C8 on extended objects. What it will bring is more image scale and more focal length. Ask yourself whether you really want larger image scale at the expense of more focal length, which will make guiding considerably more challenging. To some extent, it depends on what you want to image as to whether an investment in time and frustration, which going to 11-inches with this mount will bring, is worthwhile.

As for the EQ6 and the 11...I've done it. It wasn't much fun, but I was able to do it. Off axis guiding and a focal reducer were a must. I lowered my sub durations till I got acceptable results. I got what I was after, which was images of some planetaries for an article I was writing. What was the main problem IMHO? The biggest problem was the tripod, which is a weak link even with an 8-inch. A TPI spreader can help, and a pier is another fix if you can do that.

All that said, the mount is quite capable of handling a C11 for visual use, and can do so for imaging. The old rule of "half the payload for imaging" is a general guideline at best, and is not true in all instances. For example, the simple addition of a spreader, as above, can change that equation. The simple fact is that almost any mount will be something of a challenge to get going for imaging with a 2800mm C11.

Theodore Inlaw

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #6 on: January 12, 2018, 06:20:56 AM »
C11 on an Atlas/EQ6 works great for visual, I do it all the time.
I use my 98mm APO or 6 inch RC for AP on the Atlas with good results.Here is my DIY spreader on one of my Atlas mounts.

Rodrigo Page

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #7 on: January 12, 2018, 06:29:52 AM »
Image scale with an 8" vs an 11" won't be that much different (2000mm vs 2800mm).

You would want an SCT corrector to use the full field.

Me, I'd stick with the 8" and live with the 30% lower focal length. It's for this reason that I went with the Mewlon 210 rather than the Mewlon 250.

piesilila

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #8 on: January 12, 2018, 10:22:59 AM »
Quote
Hello All,

I was looking to get a good deal on an Atlas EQ-G mount. I currently have an 8" scope which it will more than handle. I have gotten pretty good images with the 8", but I want to know if it will handle a Meade 10" or C11 for astrophotography in the near future. I would think I'd be pushing the mount somewhat with one of those. I know that there's an unwritten rule to only pack themount with half of the weight of its limit for astrophotography, so 20lbs of equipmenton a mount rated for 40lbs. The Atlas states 40lb payload, and I believe that 33-35 pounds would be a fair estimate with a larger OTA, autoguider and camera. Anyone image with either of those 2 OTAs on an Atlas mount? Is it too much? any input would be appreciated

Regards,
SH1

Fine for visual and solar system imaging in my experience, but more than a bit sensitive to vibration, even on a parallax pier. Upgraded to a G11GT in large part due to this.

JMD

mosretouless

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #9 on: January 13, 2018, 04:10:16 AM »
I've used the atlas pro mount with a meade 10" f10 SCT and dslr with off axis guiding and it works well if it's not windy.

proporasat

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #10 on: January 13, 2018, 05:47:11 AM »
Thanks again all,
Got the Atlas today Looking atthe c9.25. thismight be a compromise between aperture and weight... want a stable AP setup... Also as I go up in aperture I will magnify the trackinglimitations as is mentioned as well as the weight. I've given up on the idea of a C11, but I think a 9.25 will be the sweet spot with this mount. Mount seems to be working well so far

Regards,
SH1

asexdalo

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #11 on: January 14, 2018, 12:08:00 AM »
Quote
Thanks again all,
Got the Atlas today Looking atthe c9.25. thismight be a compromise between aperture and weight... want a stable AP setup... Also as I go up in aperture I will magnify the trackinglimitations as is mentioned as well as the weight. I've given up on the idea of a C11, but I think a 9.25 will be the sweet spot with this mount. Mount seems to be working well so far

Regards,
SH1

Hope it works out!!!

JMD

planvelsynchcest

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #12 on: January 14, 2018, 05:22:02 AM »
<p style="margin-left:40px">Thanks!!! the C9.25 looks better and better the more I look... Thanks everyone for all your input

acbacema

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #13 on: January 15, 2018, 11:54:39 PM »
The Atlas handles the weight of a 10" Meade just fine. I have used an SN10, a 10" LX200 f/6.3, and a 10" lx200 f/10 on mine.

This is my 10" LX200 configured for imaging at f/10...
...that's an ETX-60 riding underneath as a guidescope.


Jeffrey Hunter

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Re: Atlas EQ-G mount with a C11 for astrophotography?
« Reply #14 on: January 20, 2018, 07:14:29 PM »
The Beast! The Atlas holding one of my favorite imaging scopes...
...a Meade SN10.