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Equipment Discussions >> Mounts

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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
CGEM-DX vs. Atlas
      #6160681 - 10/27/13 12:35 PM

So these are my finalists. I feel I'd be happy with either, but as I've searched all the way back to the 2011s and read every thread over and over until I've gotten here, I now need to ask some very specific questions.

There will be a Sky Watcher 100ED APO riding it along with a DSLR & finder scope ( I realize I won't need it with the CGEM-DX). I would like to... at some point be piggy backing or mounting seperatly a Celestron C6-C8. Although I'm fine using my old video tripod & head and adapter to manually view until I find a used GOTO mount for my viewing. Maybe I should be thinking seperate instead of doing it all or piggybacking (interested in your comments on that)...I have a Celestron C90 as a finder scope now that I use for polar alignment on my Astrotrac rig.

Reasons I like the Atlas:
-Never loose PA or goto availability once PA is achieved.
-Seems to be sturdier mount for less?
-Belt Driven mod potential?
-Grass is greener? My familiarity with Celestron may be tempting me to try other stuff undeservedly?

Reasons I like the CGEM-DX:
-I've used the Nexstar system and am famiiar with it albeit quite vaguely. As a techie I'm not really worried with software but I was able to navigate the software intuitively -only used it for two nights while at a star party but found it very easy to use.
-I do like the build quality of Celestron gear and assuming the same on the CGEM-DX?
-Seems to be a heavier mount, but is it more rigid? Says it is but what are your experiences?

There are a couple of things I don't like about either; Trivial I know, but I wish they were white to match my scope and refractor. At some point I'll be converting the old treehouse in my backyard to a make shift observatory. I'll be installing a concrete pier into the ground so I'll need the mount to detach from the legs, somthing I assumed both would do honestly.

So I know that is a lot, but I'd appreciate your feedback. Especially if your at a point where you have hit a problem with a similar setup and can advise me. I like to feel like I am making informed purchases. I ALWAYS LIKE TO BUY with a little headroom, WHILE BEING PRACTICAL as I very seldom buy things for hobbies, but when I do I want it to last and I'll usually use it until the wheels fall off.

I've been a sky watcher for about three to four years now and this will be my first GOTO mount. I realize it's a beast for the first GOTO but I've moved up and up with my camera equipment till I'm at the limit of what a homemade barn door, an Astrotrac & DSLR can do. It's time for a refractor and GOTO mount. I'm moving my DSLR astro gear which consists of several heavy duty heads and the astrotrac to move into this bit of astrophotography. My current 40d with mod (bought three years ago off craigslist)is sold and a Hap Griffin 60D is on it's way to him for his IR AP mod.

I feel like I've been doing this forever and haven't even scratched the surface. I lurked for years and kept my composure, building my own barn door tracker, and finally I got my hands on an Astrotrac. After about four months with exposing on it and managing some nice Nebula & Galaxy shots I realized I could go no further with it camera wise.

So here I am. I'm excited and glad I didn't jump into a telescope four years ago. I learned so much building my own rig and then seeing it perfected. Now I want presision. I know how to get the image I want and where to find it.

I appreciate all of your time and advise!

Edited by ScenicCityPhoto (10/27/13 12:39 PM)


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Dan Watt
professor emeritus
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Reged: 10/13/09

Loc: Oceanside, Calfornia.
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6160825 - 10/27/13 02:12 PM

I am a tinkerer. I always need to take everything apart and modify it for any tiny performance gain I can get. My scope, my camera, my power system, etc etc has all been hacked apart and put back together for various reasons. But you know what I haven't touched yet? My Atlas. I've had it three years now and it just works perfectly every time.

I started off on the CG-5 and quickly fell in love with the Nexstar controller. The synscan controller is a little bit clunkier but it can still do everything the nexstar can. But once you decide to play with EQMod you might as well sell the hand controller because you'll never use it except for maybe a quick visual session.

I believe the DX has a beefier tripod but I find the Atlas tripod more than adequate.

It carries my setup without issues, I very rarely have to throw out a sub because of mount issues. This image is a bit dated but you get the idea.


I haven't used the CGEM but there are a few people in the astro clubs I participate in using them. Some of them are happy, others have the cogging issues and seem to spend a lot of time cursing.


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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: Dan Watt]
      #6160937 - 10/27/13 03:13 PM

Thanks for the reply Dan! So how much would you say that telescope & finder combo weigh? How much is the most you've put on it?

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OneDaveT
sage
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Reged: 10/24/11

Loc: IL, USA
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6161080 - 10/27/13 04:54 PM

I can't speak to the atlas at all. Some strong points on the Celestron I would call attention to (YMMV):
- Celestron hand controllers and software are excellent.
- externally controllable via wifi dongles ( read mobile device and star map).
- StarSense compatibility ( plate solving auto calibrator)

Good luck,
Dave


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Dan Watt
professor emeritus
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Reged: 10/13/09

Loc: Oceanside, Calfornia.
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6161122 - 10/27/13 05:22 PM

Quote:

Thanks for the reply Dan! So how much would you say that telescope & finder combo weigh? How much is the most you've put on it?




I'd say around 30-35 lbs or so. Most I ever put on it was an 8" f8 but I only did visual with that.


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scopefreak
scholastic sledgehammer
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Reged: 04/14/04

Loc: Mayslick KY
Re: CGEM-DX vs. Atlas new [Re: Dan Watt]
      #6161418 - 10/27/13 08:13 PM

Being the owner of both the Atlas and the CGEM DX (the DX being my primary mount in my OBS), I can tell you that in my experience the GOTO accuracy of the DX is far superior to that of the Atlas. Everything I select as a target from either Sky Tools 3 or the TheSky6 Pro is dead center in the FOV of a 13mm Ethos thru a C11 at f6.3.

I can also say that the C11 rides much better on the DX then it did the Atlas. The Atlas always seemed to be straining a bit when it moved the load around the sky.

Just my 0.02 cents. No charge LOL.


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Stargazer78
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Reged: 03/05/13

Loc: Susanville California
Re: CGEM-DX vs. Atlas new [Re: scopefreak]
      #6161619 - 10/27/13 10:40 PM

I have the DX and its a awesome mount. I have had no issues at all with it. Just poor operator error . The 50lb payload is great. The mount tracks well and guides great too.

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Stargazer78
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Reged: 03/05/13

Loc: Susanville California
Re: CGEM-DX vs. Atlas new [Re: Stargazer78]
      #6161621 - 10/27/13 10:42 PM

P.S. I started with a cg5 and my god what a difference in capabilities!!!

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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: Stargazer78]
      #6162881 - 10/28/13 04:17 PM

I really appreciate all of the comments guys. I'm going back and forth and doing more research. I must admit that the lure of the Nexstar system is pulling me into the celestron DX camp.

Thanks again!


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dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6163136 - 10/28/13 06:43 PM

I just purchased a CGEM, supposedly pretty much same mount except for tripod, and I gotta tell you,,, its really sweet. I started with a SE-4, toa CPC 9.25 to a CG-5 (w/ 9.25) now to this.. I have never owned an atlas but have really heard nothing bad about them. I was considering one very seriously, but the support and 2 year warranty I stayed with Celestron,
Kasey


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scopefreak
scholastic sledgehammer
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Reged: 04/14/04

Loc: Mayslick KY
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6163247 - 10/28/13 07:58 PM

Quote:

I really appreciate all of the comments guys. I'm going back and forth and doing more research. I must

admit that the lure of the Nexstar system is pulling me into the celestron DX camp.

Thanks again!




And don't forget about NexRemote!! That is a great program and I use it each and every observing session in the OBS.

Good luck in your decision.


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orlyandico
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Reged: 08/10/09

Loc: Singapore
Re: CGEM-DX vs. Atlas new [Re: scopefreak]
      #6163599 - 10/28/13 10:59 PM

I've owned a CGEM, and all is well and good until you hit the 8/3 or cogging. As Dan has said, some of them are great, others will cause you to tear your hair out in anger (mine was the latter). Not sure what the hit rate is, because you only ever hear about the bad ones.

I am not sure if Celestron considers cogging and the 8/3 to be grounds for a warranty claim, and as Mark / stew57 has experienced, your replacement mount may not be any better than the older one.

For these reasons, I'd go with the Atlas.


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dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6163612 - 10/28/13 11:05 PM

I would go to Team Celestron and see and post questions you may have, Kasey

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shawnhar
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Reged: 06/25/10

Loc: Knoxville, TN
Re: CGEM-DX vs. Atlas new [Re: dragonslayer1]
      #6163646 - 10/28/13 11:21 PM Attachment (23 downloads)

Hypertuned Atlas (EQ6 pro) is a thing of wonder, can't speak to the Celestron but I love my EQ6! P.S,, it's white.

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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: shawnhar]
      #6163765 - 10/29/13 12:22 AM

Orlyandico,

Didn't the fix the cogging issue with a firmware update aimed at folks with the issue? That's what I've been reading. I'm a master at bricking electronics... No wait, I mean at upgrading firmware. haha.

But srsly, I did think the issue was sorted.

Edited by ScenicCityPhoto (10/29/13 01:01 AM)


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Stew57
Carpal Tunnel
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Reged: 05/03/09

Loc: Silsbee Texas
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6163793 - 10/29/13 12:36 AM

Cogging
http://www.cloudynights.com/item.php?item_id=2702
Beta firmware is close to fixing this.


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Stew57
Carpal Tunnel
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Reged: 05/03/09

Loc: Silsbee Texas
Re: CGEM-DX vs. Atlas new [Re: Stew57]
      #6163824 - 10/29/13 01:03 AM

8/3 error
http://zwilnik.net/observatory/periodic.html

My mount





The graph shows the 8/3 error 75% of the PE. The PE curves repeat each 3 worm rotation because of the 8/3 error. That means the PEC can not be relied on to reduce the PE past the 8/3 error. In fact it may add to the error at certain places in the worm cycle. If my 8/3 error were not so great and abrupt the mount would guide much better.

This data was collected at a very light load (12 lbs), when the load is increased by using the C11 and guidescope the PE runs around +-20 arcseconds with the 8/3 being just a tad more than the 75% seen here but much harder to control. Celestron has stated they believe the average CGEM/DX has an 8/3 error that runs no greater than 10 arc seconds and should be less than 5. There have been user reports of 8/3 error exceeding the integer harmonic however.

These are the thoughts on the 8/3 error by Celestron in reply to a conversation with a Celestron engineer on the teamceleston site;

"First, the 8/3 gear. Probably 90% of the customers that buy a CGEM do not even know what PE is, much less how to measure it on their mount. Of those 10%, that know about PE, most of them (mistakenly) believe you can't/shouldn't use use PEC with an guide scope, or at the very least wouldn't see a benefit from doing so. For them an 8 arcsecond term that varies over 2.5 minutes is easily guidable, smaller in fact than some of the other non-periodic terms. So that leaves about 1 percent of all CGEM owners who are inconvenienced by the 8/3 gear. "

I need to add a big YMMV!

This is the PE of the first CGEM I had with an 8 lb load. With the C11 and equipment it was 180 arcseconds;


This is a 20 second shot with the C11 at 5. In all fairness this was at the worst part of the worm cycle. It could get a approx. 30 second shot with oval stars if you hit just the right spot on the worm cycle.


It took couple of tries but Celestron did replace the mount eventually and then did again when the replacement had a problem they couldn't fix. The 3rd mount is functioning quite well excepting the 8/3 error.

Edited by Stew57 (10/29/13 07:19 PM)


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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: Stew57]
      #6163834 - 10/29/13 01:11 AM

Wow Stew! Thank you. A great read for sure.

And, yes I knew it was "cogging" but the autocorrect on my iPad really is too smart for its own good.

Thanks again for the data!


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orlyandico
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Reged: 08/10/09

Loc: Singapore
Re: CGEM-DX vs. Atlas new [Re: Stew57]
      #6163835 - 10/29/13 01:11 AM

so Mark... is your CGEM guide-able? even with the 8/3?

mine was.. guiding graph not too pretty, and i wouldn't want to image at anything close to 1000mm with it. but for a 600mm or so FL it would have worked. although it's sold now.


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Stew57
Carpal Tunnel
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Reged: 05/03/09

Loc: Silsbee Texas
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6164059 - 10/29/13 07:33 AM

Well... depends on how picky you are and what FL like you state. My goal was for 2min unguided live video at 2800mm after PEC. Of course I was deluded! With guiding the mount can be respectable but 2800mm is that is asking a lot.

Runningman snapped at sidewalk outreach. C11 at F10 2 min guided with minimal gain (as previous object had been orion and didn't want to change gain settings). I could have played with settings and gotten much better stars and PHD was calibrated on a different part of the sky. This was a passerby's request and time delay is not good for outreach. This pic for AP not good, for live video acceptable. That is why focus was not fussed with.



Edited by Stew57 (10/29/13 07:06 PM)


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ScenicCityPhoto
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Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: Stew57]
      #6164165 - 10/29/13 09:01 AM

Is that even after you've applied the "fix" Mark?

My whole reason for this mounting a AP. As my FL is 550mm with a little bit added by my crop sensor, I'm VERY concerned as to what is acceptable and what is not.


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Jason B
Proud father of 5!!
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Reged: 06/21/04

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Re: CGEM-DX vs. Atlas new [Re: Stew57]
      #6164166 - 10/29/13 09:01 AM

Having extensively used both an Atlas and a CGEM, I would take the CGEM.

The Atlas worked great, I just didn't care for the hand control. It guided well, was relatively easy to learn the controller and is reliable.

The CGEM/Nexstar system is just better for me. I get good guiding up to 1600mm with my AT8RC (15min subs are my longest) and have had none of the issues you repeatedly read about here. The Polar Alignment routine works great for me as well and allows me to quickly set up with my limited time available this time of the year (if it actually clears here in Michigan!). In the astrphoto group in my club, 2 other CGEM's have worked just as good and one of them has done up to 5 min guided exposures at 2000mm with good results (C8). All 3 of our mounts are good, if not great, imaging mounts for what we use them for. All are 3 years old or newer.

There are good and bad stories for every mount in this price range so you just have to go with the features that are best for you. YMMV as has been said many times.


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Stew57
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Reged: 05/03/09

Loc: Silsbee Texas
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6165214 - 10/29/13 07:30 PM

Here are 4 2 min shots (one complete worm rotation) unguided, C11 F10.
http://s906.photobucket.com/user/mstew57/library/CGEM/CGEM%20tests?sort=3&...

At <600mm FL and minimal weight you will get good results. I would think you will still have to guide though, but you could use a miniguider or finder turned guidescope. But then again your mount may be better. The old YMMV still applies.


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warren2256
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Reged: 10/07/13

Loc: Rosenberg Tx
Re: CGEM-DX vs. Atlas new [Re: Stew57]
      #6165413 - 10/29/13 09:39 PM

ok newbie question but what exactly is the 8/3 cogging mean? i just got a 800 hd cgem version not dx and you all have me worried... not to sure what yall mean by it

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orlyandico
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Reged: 08/10/09

Loc: Singapore
Re: CGEM-DX vs. Atlas new [Re: warren2256]
      #6165425 - 10/29/13 09:45 PM

Warren, 8/3 and cogging are different.

8/3 is a periodic error with an irrational period (2.667X or 8/3 times faster than the fundamental) that cannot be removed by periodic error correction. This 8/3 error is due to the gearbox of the motor in both the CGEM and DX.

For "most" CGEMs according to Celestron the 8/3 is of small magnitude, under 8 arc-seconds peak to peak, but on some - like mine and Mark's - it was huge (over 25" peak-to-peak).

The cogging is the tendency of the declination motor to resist small movements (to "cog" as if it has detents) which gives problems when guiding in declination. Supposedly fixed now with new firmware, I have no way to check as I sold my CGEM.


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petemumbower
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Reged: 07/12/09

Loc: West Michigan
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6165435 - 10/29/13 09:53 PM

Tough thing here is you seem to either get a decent CGEM or a bad one. Though the there seems to be more "Good" vs "Bad". I have worked the TeamCelestron.com site beta testing the firmware to fix the cogging and I must say it is a non issue now for me. Though the 8/3 is still there in my mount.

I seem to have a decent one that is guideable. Below is an image of M1 taken at f/10 with my c9.25 (2350mm) with 2 and 4 min subexposures.



Edited by petemumbower (10/29/13 09:53 PM)


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orlyandico
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Reged: 08/10/09

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Re: CGEM-DX vs. Atlas new [Re: petemumbower]
      #6165460 - 10/29/13 10:03 PM

of course.. squeaky wheel and all that. You'll always hear from the guys like Mark and myself who got burned. So our experiences probably don't represent a majority of CGEM owners. But the possibility is there.

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petemumbower
Carpal Tunnel


Reged: 07/12/09

Loc: West Michigan
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6165479 - 10/29/13 10:12 PM

I agree and it is good to know about the good/bad for a mount in this price range before getting one. Good for entry level AP and even intermediate-advance if you are dedicated to working with the mount and working within its limits. That being said, I am working toward getting a AP900/1200 class mount to take my work to the next level.

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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: petemumbower]
      #6165573 - 10/30/13 12:22 AM

hHello,I've been reading the entire thread, which i find really interesting but at this point i arrived at a question that came to me naturally and it is the same i asked myself 6 months ago:

If someone wants to do photography (entry or intermediate level)..then..why get a mount that has both an uncorrectable error (probably guidable,probably not,and if if so...the guider should work both against PE and the 8/3 error which is not fantastic actually)..and a possible cogging issue?
Just for the Nexstar software?(which i do like alot due to my previous mount a CG5..)

Isn't it better to eliminate at least from the begining 2 factors that will eventually make things more difficult in photography? (8/3 and cogging)?
I mean let's face it..both the Atlas and the CGEM series are not Astrophysics mounts (sorry if i'm blunt)..so..why complicate things with 2 extra errors plus the usual PE,wind,seeing etc someone has to deal during the night?

I put these things to the scale and..at least for me it went towards teh Atlas/AZEQ6 even if Nexstar can be more user friendly.

I haven't chosen the Atlas way immediatelly i must say..i have been waiting for around 2 years to see how the situation will evolve with the CGEMs because i like them but..to me it seems the situation is not changed.
This is just my thought of course nothing more.


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Stew57
Carpal Tunnel
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Reged: 05/03/09

Loc: Silsbee Texas
Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6165588 - 10/30/13 12:35 AM

The cogging is to be a non issue very shortly. They have emailed me a few times stating that a fix for the 8?3 error is in the works, but I have not heard anything recently. The pointing accuracy, ASPA, and the HC software in general is hard to beat. Of course the Atlas has an ASPA type routine now and EQmod.

Personally I am counting pennies trying to go towards an EQ8 class mount.


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orlyandico
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Reged: 08/10/09

Loc: Singapore
Re: CGEM-DX vs. Atlas new [Re: Stew57]
      #6165607 - 10/30/13 12:46 AM

this is what i keep saying.. i agree with Mike X.

it's good that the cogging is getting fixed.. after how many years?

i don't think the 8/3 can be fixed in software. it will require a gearbox swap. So unless the gearbox swap is free for existing or new CGEM owners, that would be an extra cost.

the Atlas simply has less that can go wrong with it - stepper motor drive, so dead simple. The gearbox has two gears (!) and a low reduction, so there are less gearbox induced errors.

that said the EQ8 with its no-gearbox design is taking simplicity to the extreme. and why not? no gearbox means no gearbox periodic error. because the only way to get rid of gearbox errors is to make or use an expensive gearbox. as I understand it, Astro-Physics doesn't even use a stock Maxon gearbox, they make their own.. (and Maxon gearboxes are pretty high-end)


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warren2256
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Reged: 10/07/13

Loc: Rosenberg Tx
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6167215 - 10/30/13 08:19 PM

well im barley getting stated into AP havent noticed yet... but thank you for the response, definitley going to keep an eye out!

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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: warren2256]
      #6167239 - 10/30/13 08:29 PM

Indeed the EQ8 uses belts just like the AZEQ6 if i'm not wrong..which i'm really really happy so far both from a tracking and goto point of view.

Edited by Mike X. (10/30/13 10:04 PM)


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WesC
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Reged: 02/06/13

Loc: La Crescenta, CA
Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6167335 - 10/30/13 09:18 PM

The only reason I got a CGEM is because it came with my C11 Edge for an extra hundred bucks!

But honestly, for visual it has been a great mount.


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tim57064
Pooh-Bah
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Reged: 08/23/12

Loc: Southeast South Dakota,USA
Re: CGEM-DX vs. Atlas new [Re: WesC]
      #6167375 - 10/30/13 09:40 PM

Has anyone ever used a 10"SCT on a cgem permanently mounted on an OBS concrete pier for AP? Or an Atlas?

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ur7x
sage


Reged: 01/08/12

Re: CGEM-DX vs. Atlas new [Re: tim57064]
      #6167390 - 10/30/13 09:49 PM Attachment (32 downloads)

I have a 9.25" on my pier mounted CGEM. Works great.
Could probably get away with a 11"

I guess a photo might help.

M51. 3x 90 second unguided F6.5 reducer Stock Canon T3i

My pier is a thick steel 60+ pound monster that is itself a foot underground and is bolted to a 5' deep "blob" of concrete that is about 1/2 of a yard big... 3 LARGE wheelbarrows full of concrete (at least 1000 pounds of rocks and and cement).

You can bang the pier with your hand and the scope barely giggles visually.. Having the base literally rock solid makes a huge difference.


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Raginar
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Reged: 10/19/10

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Re: CGEM-DX vs. Atlas new [Re: tim57064]
      #6167391 - 10/30/13 09:50 PM

Tim, I had your scope. It was mounted on my wooden pier (6x6, 3' deep) on a CGEM. It wasn't good for imaging. The CGEM could 'barely' tolerate it. But with the right balance it was doable for visual. For imaging? No way.

My 12" is currently visual only. The 6x6 just isn't good enough. I'm probably gonna rip it out next summer and sink a real pier.


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tim57064
Pooh-Bah
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Reged: 08/23/12

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Re: CGEM-DX vs. Atlas new [Re: Raginar]
      #6167449 - 10/30/13 10:33 PM

Thanks for the info Chris.Guess I was hoping the CGEM would be doable at AP with the 10. Gonna continue keep an eye out for the Atlas EQG I guess.

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jrbarnett
Eyepiece Hooligan
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Reged: 02/28/06

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Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6167531 - 10/30/13 11:29 PM

The CGEM and Atlas heads have virtually identical capacity. The DX gains it's extra payload capability courtesy of one of the heaviest tripods in the world. A tripod made for a 100# mount head but used for a 40# mount head instead. If you're pier mounting it they are 6 of one, half dozen the other. Particularly if you retrofit the Atlas with the larger counterweight shaft. If you need the extra capacity of the DX and plan on using the native tripod, then it is really your only choice in this general price range (assuming GOTO). The standard CGEM and Atlas are closer, with identical capacities.

The Atlas supports EQMOD. The CGEM twins do not. Nexstar firmware is much better than Synscan though.

If you don't need GOTO, the standard non-Gemini G11 is a similarly priced, better made mount with much higher capacity. Just another option.

- Jim


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Moromete
professor emeritus


Reged: 02/15/12

Loc: Romania
Re: CGEM-DX vs. Atlas new [Re: jrbarnett]
      #6167642 - 10/31/13 01:08 AM

AZ-EQ6/ATLAS PRO AZ is a viable option too and it's better than EQ6/Atlas. This dual mount coppied Losmandy G11 slip clutch system for both axes.
In my very short experience with Synscan HC and much longer with Nexstar HC, I can tell you that AZ-EQ6 can reach the pointing accuracy of a CG5GT(after 2+2 star alignment) or maybe exceed it a little ONLY if you use the right mix of 3 alignment stars as I have seen so far. With the right mix of 3 stars AZEQ6 will any dso in the FOV of a Mallincam or eyepiece at ~100x with a C11.

Even so I still find Nexstar easier to align than Synscan because with Nexstar I have very good gotos without being too carefull which stars to pick as long as I do 2+2 star alignment. With Synscan it seems you have to be very carefull what stars to pick for alignment and avoid Vega as 3rd star for correcting cone error.
So yes, Nexstar has a more advanced sky modelling which gives very good gotos easier. Also Nexstar has unique functions like Goto Precision, reduced speed of crowling text on display for winter nights, much more alignment stars for 2nd and 3rd star, probably still better ASPA, etc.
I see Nexstar as a Mercedes and Synscan as VW somehow.

Oh, AZEQ6 is much more quiter a max speed when slewing than a CG5GT and probably a CGEM too.

For anybody wondering the dual encoders of AZEQ6 really work well enough even if you declutch on both axes. The gotos will be just a little worse but still good: e.g. suppose you have a dso in the middle of the eyepiece at 100x after a 3 star alignment, than you decluth both Ra and Dec axes and move the mount on another part of the sky, and finally you engage the clutches again and do a goto to the same or another dso. The dso will land somewhere in the FOV at 100x as I have seen.

In plus you can use AZ-EQ6 in AZ mode with 1 or 2 scopes when doing visual work only and still have goto capability which is unique in this class of mount.

One point to note: in Europe AZ-EQ6 costs the same or less than the standard CGEM, not DX.


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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: Moromete]
      #6168875 - 10/31/13 04:41 PM

I really want to thank everyone for the discussion and suggestions.

At this point, I've decided to eliminate the CGEM-DX simply because of the cogging issue. Regardless if it's corrected eventually or not, the simple conclusion for me is, "why spend money on something hoping it gets fixed".

If it's corrected with firmware before I purchase my mount then I may look at it, but for now it's off the list.

I'll manage with Nexstar just fine. If I can take a photo of a galaxy with a camera and a cheap tracker on a decent tripod I'm sure I can navigate clunky software.

So for now, I'm looking for an Atlas, but as I read I may be move up to the Atlas Pro belt driven mount.

Squeaky wheel or not, an issue is an issue and nobody buys a boat with a hole in it if they know it's there. Well, at least I don't.


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bhwolf
member


Reged: 08/04/12

Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6168905 - 10/31/13 05:04 PM

I thought the cogging was fixed in the latest beta motor control firmware -- I haven't had a chance to load it yet but was going to do so soon. Feedback on it seems positive. You might want to join the beta @ teamcelestron just to read up on it, if that's a mitigating factor.

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orlyandico
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Re: CGEM-DX vs. Atlas new [Re: Moromete]
      #6168985 - 10/31/13 05:50 PM

The cogging is IMHO less of an issue than the 8/3... cogging is really bad and prevents guiding in DEC, but a firmware fix can address that.. or really good polar alignment.

The 8/3 is not fixable in firmware and can be either a small hole or a really big one.


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ur7x
sage


Reged: 01/08/12

Re: CGEM-DX vs. Atlas new [Re: bhwolf]
      #6169259 - 10/31/13 09:22 PM

Cogging was an issue with some CGEMs not all and Cogging was resolved in the last beta firmware release... Which is reported to being going "public" in a month or so...

I can report that my CGEM has no cogging issue and I haven't run into the dreaded 8/3 problem either but then I have become a fan of short exposures and post imaging stacking.... This simple application of cheap technology solves a hole host of challenges with this hobby....


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: ur7x]
      #6169550 - 11/01/13 01:26 AM

So if I understand well short exposures help to bypass the 8/3 and cogging issues..and thats a way to come around the problem but I believe though that they can't substitute always longer exposures.
What if someone needs to go deeper on the picture and capture fainter objects that need exposures of at least 10 minutes...or for making it simple...what if someone has to do exposures of 20 or 30 minutes because uses Halpha;,O3 and S2 filters? Both issues inevitably will be present ( unless fixed) in every single exposure as I understand that the period of the Cgem Is less than 600 seconds..and ...if not ruined , every sub will be influenced in a way..:(...specially at longer focal lengths...


Edited by Mike X. (11/01/13 01:30 AM)


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orlyandico
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Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6169620 - 11/01/13 04:11 AM

well imho if you're doing 20-30 minute exposures you're simply asking too much of a CGEM.

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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6169750 - 11/01/13 07:58 AM

Hello orlyandico, I can't imagine why since if the worm period is covered well by the auto guide there should not be problems go higher with times.

My recent experience with the azeq6 was extremely positive and I bet the built quality is approximately similar since it is a Synta mount after all.
I do usually 10 minute exposures and I don't lose a single one during the night due to tracking errors.
15 or 30 minutes exposures are really possible as I have tried them.( the sky I have won't take them though as it gets saturated If I go higher than 12 mins)

Now lets leave the huge 15 or 30 mins exposures ..Imagine if someone gets 10 min exposures that are very common and has to keep 2/3 or 1/2 Of them during the night because of tracking errors...now that's a huge loss of time and effort...at least from my point of view....That's a scenario I was experiencing before with the cg5 that has even a longer worm period ( 596 seconds)..that's why I am so positively impressed with the new mount.

Ps please don't take wrong I don't want to say the celestron mount or that the cg5 are not good.The cg5 still serves me well within it's limits. It 's just that the new one ,at least for me,works much much better

Edited by Mike X. (11/01/13 08:22 AM)


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Jason B
Proud father of 5!!
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Reged: 06/21/04

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Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6169850 - 11/01/13 09:28 AM

I do 10 to 15 min exposures all the time with my CGEM. I realize that my expereinece is not representative of all the CGEM's out there but neither are the problems repeatedly stated here about a 2 or 3 bad mounts.

Whatever you use or purchase, the most important part is that it satisfies your needs.


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: Jason B]
      #6170017 - 11/01/13 11:04 AM

I totally agree!

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dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: CGEM-DX vs. Atlas new [Re: Jason B]
      #6170027 - 11/01/13 11:09 AM

As a new owner of a CGEM, used once so far, I am really happy with it, really happy. I have not guided with it yet, just tring unguided exposures while dodging every neighbors porch lights.. Am running a C 9.25 + Orion ST80 piggybacked + crayford + Dewshield + Videocam... Will have to reconfig Nikon DSLR and test long exposures sometime and see what I get.. but till then, I am happy so far, Kasey

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Wmacky
Carpal Tunnel
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Reged: 11/24/07

Loc: Florida
Re: CGEM-DX vs. Atlas new [Re: dragonslayer1]
      #6170639 - 11/01/13 04:49 PM

As a person that "always seems to get the bad one" I appreciate these reports and warnings. Perhaps they will lead to less bad ones........

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ur7x
sage


Reged: 01/08/12

Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6171317 - 11/02/13 12:40 AM

Quote:

So if I understand well short exposures help to bypass the 8/3 and cogging issues..and thats a way to come around the problem but I believe though that they can't substitute always longer exposures.
What if someone needs to go deeper on the picture and capture fainter objects that need exposures of at least 10 minutes...or for making it simple...what if someone has to do exposures of 20 or 30 minutes because uses Halpha;,O3 and S2 filters? Both issues inevitably will be present ( unless fixed) in every single exposure as I understand that the period of the Cgem Is less than 600 seconds..and ...if not ruined , every sub will be influenced in a way..:(...specially at longer focal lengths...





You answered your own question in your subsequent post. Most people live in places that yield background noise washout at ISO400 in 10-12 minutes. In my yard my CGEM will also produce perfectly repeatable 30 minute subs...of any part of the nights sky. Of course I can produce the same thing by taking a photo of a piece of gray card stock.

I have yet to find my mount to be my limitation. There are lots (too many really)of potential targets for my light polluted backyard. Someday I will solve this when I'm retired and I spend my nights on the top of a Hawaiian volcano taking photos.. Of course then I will discover the trade off of portability and set up and take down. My CGEM is already pretty heavy, the DX is even worse, its lunar lander tripod is a total beast.

The point is there is no such thing as a perfect mount. You will always be faced with a trade off... Discussion of 20 minute subs from urban locations on $1200 mounts is mostly moot. Its like trying to find a $20,000 vehicle that seats 5, goes 0-60 in 4.5seconds and get at least 35 mpg... of those 4 requirements... you can find lots of vehicles that will do 3... but pretty much none that do all 4... mounts are like that to.

Unguided my CGEM will cough out 90 second subs without issue.. guided I can easily produce 3-5 minute subs beyond that, at my viewing site, it is really diminishing returns.

My advice is simply buy the "strongest mount" that you can afford, move around, comfortable set up and take down (in the dark). Pick one with a large user base and a strong track record. And of course every mount will work better on solid pier. But Piers have their trade offs too.

I don't own an Atlas, never used one, so I can't comment on that mount. But if I were to buy a mount today. I would actually lean towards the Atlas... or wait for 6 months to see if Celestron adapts the AVX motors to the CGEM... if/when that happens that will be a very nice mount.


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orlyandico
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Reged: 08/10/09

Loc: Singapore
Re: CGEM-DX vs. Atlas new [Re: ur7x]
      #6171398 - 11/02/13 02:37 AM

there's one reason to go 30 minutes from urban sites. narrowband.

i am curious as to (1) the keeper rate; (2) the focal length; (3) are you using a refractor or SCT; (4) are you using OAG - for Jason B.'s claim of "10 to 15 minutes all the time with a CGEM."

Over on TeamCelestron there was a guy imaging at 1600mm+ with an EDGE on a CGEM, and 20-minute plus exposures. But he had an AO unit.


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: ur7x]
      #6171406 - 11/02/13 02:49 AM

I understand what you say but I never talked about taking photos from urban locations.i was talking about the mount in general. Personally I don't take photos from urban or suburban locations for example and if I would I would definitely use selective filters otherwise it has very little sense...at least for me.

A 1200 mount of course is not a mount I can pretend miracles from but that's no excuse for getting cogging issues or the so called 8/3 error...plus...3-5 minutes of autoguided shot is barely an achievement for any equatorial mount even a cg5 or a neq3.
What I do pretend from a mount though of 1200 € or $ is to work as intended...no miracles,no fantastic unguided shots or resolutions but at least work without cogging or extra PE induced by who knows what or 16/17 errors etc Etc etc.

Anyways long subs from urban locations with narrowband filters are the only way to do dso immaging for someone that cannot move and still wants to go deep..Otherwise light pollution will limit the session with shallow subs just as you mentioned .

It is not uncommon to do such kind of long subs with 1200 $ mounts.
Many people actually follow this path for urban locations by photographing in ha ..and actually with great results.

Edited by Mike X. (11/02/13 02:54 AM)


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Jason B
Proud father of 5!!
*****

Reged: 06/21/04

Loc: Mid-Michigan
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6171621 - 11/02/13 09:28 AM

Quote:

i am curious as to (1) the keeper rate; (2) the focal length; (3) are you using a refractor or SCT; (4) are you using OAG - for Jason B.'s claim of "10 to 15 minutes all the time with a CGEM."




My "keeper rate" is in the 90 to 100% range if you don't include airplanes (I am between two international airports, Lansing and Grand Rapids, pain in the but).

I have 3 main imaging scopes (I have been experimenting with guidescope combos so bear with me):
An AT65 that I guide with a Orion SSAG/50mm Finder combo or it rides on the AT111.
An AT111 that I guide with the AT65 or the 50mm finder. I use the finder when traveling, the AT65 from home.
An AT8RC that I guide with the AT65 or the Miniguider. I don't travel with this set up. When I travel, I always take the AT111 or AT65. Mostly the 111 as I don't care to image from star parties and that is my favorite of my scopes for visual.
I tried using an AT10 F4 Newt but it was just too much for my mount. It seemed to guide ok as I got some good shots through it but the slewing seemed to really work my mount and I also found that being short and imaging with the newt was awkward.

I have gone up to 15 minutes with all 3 set ups. I don't do this on most targets as I shoot a lot of bright objects and being solely DSLR, these longer exposures really create noise issues with my DSLR. Here are a few example shots with the 1600mm AT8:

NGC891 with 10 minute subs
IC5146 with 10 min subs
Hickson 44 with 15 min subs

I am very meticulous about set up. I do my 2 + 4 and ASPA using the cross hairs on PHD with my SSAG through the main scope. I make sure it is perfectly balanced in DEC and barely east heavy in RA.

The only thing that I did to the mount (it was a display mount at NEAF) when I got it was adjust the play in DEC. I have not taken it apart and hypertuned or anything like that.

Look, I understand that not every mount coming out of Celestron or Orion or most of the other Chinese mount importers/makers will perform as well as mine. I am also sure that not every mount will perform as bad as yours or Stew57's did either. I just want to show that a serious imager can work with a CGEM. Did I get lucky? Maybe but so did two other members of my club that image as well so I know that it is more than just mine. Do I want to upgrade my mount someday? Heck yeah, at some point I will move up to the big boys like an AP, etc but it won't be because of a lack of performance from my CGEM. It will be when I have my own observatory and a large scope/camera set up to image my favorite objects, Planetary Nebula (and have a lot more money in the bank! ).

Everyone's mileage can and will vary of course.

Sorry for the long post!

Edited by Jason B (11/02/13 10:01 AM)


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ur7x
sage


Reged: 01/08/12

Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6171652 - 11/02/13 09:52 AM

Quote:

3-5 minutes of autoguided shot is barely an achievement for any equatorial mount even a cg5 or a neq3.





I completely agree! and that was exactly what I was trying to say. For just about anyone, living in (or near) a town of 100K or more (which is about 90% of us) you will have positive results with either mount. (or even a AVX, CG5, EQ3, etc as long as your OTA isn't too large or too heavy).

Back to another car analogy, where I live, my morning commute is about 30 minutes...I do it in a 5 year old Lexus Sport Sedan... that commute would be pretty much the same duration in a 1969 GTO, a 1990 Corolla, or a 2013 DB9. The car is not the limiting factor in the duration of the commute, congestion, road conditions, and traffic fines play a larger role then how fast (or slow) the car you buy is. Of course all four of those cars offer a completely different ownership cost and experience.

For most of us any decent mount that can hold the scope steady and can track the night's sky will produce photos like the one I posted a page or two ago.

There are lots of reasons to pick the Atlas, there are lots of reasons to pick the DX. Both can and do work. For most of us, due to other limitations, neither will work better than the other.


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: ur7x]
      #6171949 - 11/02/13 01:16 PM

The point is, the 8/3 issue and the cogging prevents (at least from what i read both here and on the yahoogroups) the CGEM to act as a decent mount for DSO photogaphy--or is a cause of frustration for many users.So if not all many CGEMs do present this issues..otherwise i don't understand all the fuzz around these issues...
Plus we have to keep in mind also expectations. From person to person may be different regarding the mount and it's performance.
Of course noone will see this issue in visual or hi res photography and of course many friends that do low focal lenght photography might not even notice the issue...but still a problem is a problem and the statistics of how many use the mount in a certain way or not won't change the fact that the problem exists..and...for 1200$ i just cant't accept to get a defective product since there are alternatives...because even if it's not a state of the art mount...1200$ is still good money for many of us..if not a lot...not talking about the difference of having fun shooting the stars instead of "having fun" trying to "solve" a congenital issue of the mount

I can accept the fact that i have to tinker to improve performance, it is perfectly normal in ths range of mounts..but fix an issue that comes from the production line?...

PS:I read loads of posts about the hit or miss probability to get a mount really affected by these issues...and that's what made me change my mind..Not because there aren't CGEM's capable of delivering excellent results but because , at least from what i understood it is like playing Russian roulette to get a lemon or not.

I know i'm blunt guys, please don't take it bad , it's only my opinion and nothing more.

Edited by Mike X. (11/02/13 01:24 PM)


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ur7x
sage


Reged: 01/08/12

Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6172123 - 11/02/13 03:19 PM

Let me help clarify and explain the fuzz.

First off Celestron Software Engineers have resolved the cogging problem, a software patch for the subset of CGEMs that exhibit this problem has been available for a few months now. Of course cogging was only an issue while guiding long exposures on the Dec axis and again short exposures and a bang on polar align will solve that issue without any patches or tinkering. Bang on polar alignment is not tinkering for AP... it is kinda a prerequisite.

Next, the 8/3 problem basically makes the PEC system, dare I say it, useless. In this case we see lots of evidence that just about any decent guide scope and camera can easily deal with this problem to the limits of most sites seeing conditions. Again, it is hard to describe bolting on a guide scope/camera, turning off PEC and letting it all do its thing as tinkering.

Would it all work better if the PEC system was more effective? Sure... Is there ample evidence that the CGEM can take pretty nice Deep Sky photos? Absolutely. Is it possible to take shots of even mag 20 objects using stacked 90 second subs... Of course. We see examples of photos like that in this thread.

You are starting to lose me, I'm not sure what you are trying to express. Would the CGEM be better if it had the AVX motors and gears? Again, absolutely! Does it work fine as is today? Yup. Is it better than an Atlas? No... Is the Atlas better? debatable.


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: ur7x]
      #6172234 - 11/02/13 04:31 PM

Sorry if i lose you , that's not my intention of course.

It happens to know how important polar alingment is as i do DSO photography myself for several years now and of course that is not tinkering.
Tinkering is to have to "hypertune","overtune","supertune" a modify or enchance a mount to perform better than it does right out of the box..just for making things clear.

What i mean is that a mount with a problem coming out of the factory (and that has not been solved up to ...afew weeks-motnhs are you say with a software release) for the cogging issue (they can't do much for the 8/3 issue with software unfortunatelly) is a no deal for me.

Now if the CGEM had no such issues (it came out in 2009 if i remember well) i would no doubt get one instead of an Atlas and not because one is better than the other..but because i like it more.But it did had and it stil does have the 8/3 so..since there is the option to avoid it...i chose to void it.It's that simple.
One less factor that introduces PE to the system is good enough for me to chose that mount over another.

What i find debatable is the equivalence of short exposures VS long exposures for the same amount of integration.
If that was true..noone would bother to guide or even get an expensive mount..everyone would go with 1 or 2 second shots..thousands of them so the noise would be so low they would not even need to pass any denoise filter or even bother to shoot darks.

So for coming in topic at this point where the CGEM and the CGEM DX still have the igarshi motors, still present the 8/3s issue..etc etc..to me are a step down over their counterparts.
They do have the potential to deliver identical results, they do have the potential to be better as a whole..but at least for me..where tracking counts more over esthetics and electronics...they are not.

Edited by Mike X. (11/02/13 04:34 PM)


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ur7x
sage


Reged: 01/08/12

Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6172445 - 11/02/13 07:17 PM

Quote:


Everyone would go with 1 or 2 second shots..thousands of them so the noise would be so low they would not even need to pass any denoise filter or even bother to shoot darks.





That is not as much of a strawman as you intended. Depending on how bright the object is the technique that you scoff at is actually preferred for taking shots of objects like Jupiter, Saturn, Mars, etc. Thousands of short exposure shots is exactly how a Webcam cam produce stunning images of brighter objects.

Just as sky glow will actually diminish results after 10 minutes (as you posted) Ultra short shots have the same problem at the other end of the spectrum depending on dim you want to go. Of course you and I both know that most of the Messier objects can be easily capture with 60 second subs... Some of them will come out nicely with one 60 snap. I have been doing deep sky photography since the mid 80's I have struggled with 35mm slides, cold cameras and uber long focal length guide scopes as I stare into illuminated eyepieces nudging the mount with frozen hands on slow-mo buttons.

As you say, to be blunt, if you want to have a discussion of deep sky techniques, I'm game, if you only want to throw out extreme strawmen arguments then I'll bow out of this.


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: ur7x]
      #6172643 - 11/02/13 09:32 PM

i find noting extreme by taking a postition ,with reason towards a mount choice urx7x.Plus that remains my personal opinion only and it is always open for debate. I was blunt regarding the mount and nothing else.I wouldn't even dream to be blunt towards a fellow astrophotographer or observer.
I would be and I am always happy to discuss and exchange opinions regarding astrophotography techniques but this would be by far off topic on this thread.
I find the same extreme to put on the same basis the needs of everyone that buys a mount of 1200 $ and say ..." Hey ...after all 90% of us live in urban locations..it's alright even if the mount is not working properly...I will find another way around by reducing my exposures,avoiding guiding in dec ,changing my targets or even accepting the fact that that the sky has only 110 objects and a few solar system objects....

I don't throw out extreme arguments and I'm always ready to accept I'm wrong but isn't it extreme too to keep denying the most evident thing?
The Cgem had design flaws ,some got probably fixed by the beta patch ( i guess the cogging) released recently and some still have to be solved ( the 8/3 error).
Flaws that for some are less important than others.
After all this is a forum,we are here to discuss we have nothing to divide.

Here is an example with my mount if it can help make underhand what I try to say regarding the mount.

My azeq6 has a power leakage when powered with a ac/dc adapter.It still works fine , tracks perfectly and points like a charm..but hey..it shouldn't do that! Maybe I am doing something wrong, maybe the mount has an issue.With some friends we tested several mounts, even with the dealer here in Rome, all presented the same issue....
If we power up the mount with a battery ...of course there is no leakage...but that doesn't means is a solution or that the mount doesn't has an issue ..since it is designed to work even if powered by an adapter.It is only a remedy, just like reducing the exposures or keeping guiding in dec to a minimum or zero.

I don't know maybe it is my fault that I can't explain myself ,it is evident that my English is poor but please understand that I don't seek any kind of argument.iT has no sense to argue over a piece of equipment .

PS .and of course I would love to discuss with you about astrophotography techniques and exchange opinions whenever and occasion will be presented

Edited by Mike X. (11/02/13 09:39 PM)


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Moromete
professor emeritus


Reged: 02/15/12

Loc: Romania
Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6172992 - 11/03/13 01:56 AM

Mike, actually it seems to me there is nothing wrong with your mount regarding the power leakeage because at the bottom of page 17 of AZ-EQ6 manual (not Synscan manual) is written:
- " Do not use an un-regulated AC-to-DC adapter. When choosing an AC adapter, it is recommended to use a switching power supply with 15V output voltage and at least 3A output current."


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: CGEM-DX vs. Atlas new [Re: Moromete]
      #6173148 - 11/03/13 04:50 AM

Hello Moromete i think too this is the case at the end.I am also waiting confirm from the importer just to be sure,I believe in a few days to have it,and of course I will let you know;)

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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: Mike X.]
      #6178968 - 11/06/13 10:44 AM

So I had a unique opportunity to use the Atlas at a friend of an acquaintance's house, I know right?!?. And the best part? I also got to try out the CGEM a week ago as well at another persons house (read- see it guide, operate, take an image at 3min).

Unfortunately, I came away like the exposure I took on the CGEM better. Admittedly, there was better seeing with the CGEM, but the single exposure was better in detail (same scope on both). The setup was way faster and both persons had to setup from scratch. I think the CGEM user was definitely more tech friendly, but total time to imaging was around 30-45min I'd guess. The Atlas user had stated he was having trouble with the alignment and that it was tricky for him as he could not see the Northern star, save for through the trees which made me wonder if he even aligned on Polaris and maybe not another star. It took around an hour and a half to get in tracking and guiding and he had software issues again because of Windows 7 wanted to update. lol. Both users told me they have imaged for 3-5 minutes, but the Atlas user said he usually just did around 1-2 minutes and stacked them. He showed me some of his work, great stuff.

I walked away feeling the CGEM was the mount for me once again. Even though I didn't want to even consider it with all the issues. So I called my buddy who manages Best Buy and can order the CGEM DX and inquired as to return policy, should there be an issue and was told it would be covered by the "marketplace vendor" they use for 14 days. Another awesome thing is that it's on sale. The DX is $1699 on amazon & best buy, that's $500 cheaper than it was last week and $500 cheaper than the Atlas. :/ Oh man, not making it easy.

So now I'm wrestling with the issue again, despite all of this good info on the issues, I'm wondering if I might hit the lottery or reap the whirlwind.

Man, I'm torn. I don't need convincing, I'm going to make up my own mind. I appreciate all of your help in my decision and I feel at this point, I'm making a very informed decision either way. Looks like I'll just be taking my chances.

One question I do have is, WHERE DO YOU GUYS get your gear? Who is the best with customer service and help when there is an issue?

In the mean time, here is my SWAN SONG from my astrotrac and DSLR. She was a gateway drug for me. I feel I have taken it to the VERY limit of what it can do!




Edited by ScenicCityPhoto (11/06/13 10:51 AM)


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orlyandico
Post Laureate
*****

Reged: 08/10/09

Loc: Singapore
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6179011 - 11/06/13 11:13 AM

The atlas probably had less good results due to poorer polar alignment... That said the newest synscan firmware also has an all star polar align routine.

If I were you, wait till Christmas. Who knows, a CGEM AVX might be announced and all the CGEMs will lose half their value.


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dragonslayer1
scholastic sledgehammer


Reged: 02/25/12

Loc: SLC, UT
Re: CGEM-DX vs. Atlas new [Re: orlyandico]
      #6179129 - 11/06/13 12:23 PM

I have another input.. I just bought a CGEM and love it,,,, I saw them on sale and waited uggghhhhh, missed the sale and bought full price,,,,, a week or two later they are on sale LOL,,, "get while the gettings good",
Kasey


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DaveJ
Carpal Tunnel
*****

Reged: 01/07/05

Loc: NE Ohio
Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6179457 - 11/06/13 03:08 PM

Quote:

The DX is $1699 on amazon & best buy, that's $500 cheaper than it was last week and $500 cheaper than the Atlas...
One question I do have is, WHERE DO YOU GUYS get your gear? Who is the best with customer service and help when there is an issue?




Here's where I got mine: Link. I've always had great service from Astronomics. Same price, free shipping and a full two year warranty.


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ScenicCityPhoto
member


Reged: 10/17/13

Loc: Chattanooga Tennessee
Re: CGEM-DX vs. Atlas new [Re: DaveJ]
      #6275424 - 12/27/13 01:54 PM

Well guys, I'm back.

I always like to come back and give info on what I've discovered for folks who actually use the "Search" feature.

So, two months now with a used CGEM DX and I couldn't be happier.

I'm imaging for 3 minutes at 550mm with a Skywatcher 100mm ESPRIT. I bought a used setup with a broken focuser and while I'm very happy with optics of my 100mm ESPRIT, the bent focuser leaves much to be desired. After the new moon in January, it's going to moonlight to be customized. It is serviceable now, but a pain.

The CGEM DX I got was one with the newer electronics and could track for 3 minutes unguided with NO ISSUE. The guy I got it from was convinced it had a terrible 8/3 issue, but I've seen no issue with it. I think he had too much weight on it with a giant reflector and a refractor. What I paid was ridiculous so I jumped on it. I feel very lucky as I did take a chance, but I also believe had I not been a fairly "tech-oriented person" I would have been lost fixing the few things wrong with my used setup. The tripod had taken a spill and the previous owner had managed to slew the telescope so far it snapped the power connector from the board damaging the coupler. Easy fixes with the right parts. The motors were LOUD and I was worried one was about to fail as it sounds precarious, but it's held out like a champ.

Anyway, here's my latest photo from the Horse Head & Flame Nebula.

41 lights & 41 darks @ 3 minutes each, ISO 800 on a Hap Griffin modified 60d. Around 2 hours total integration. Taken with a CGEM Mount & a Skywatcher 100mm Esprit. Edited in Deep Sky Stacker, & PS.



And my personal review of the CGEM DX:

PROS-
- GREAT software and support
- Controlling with iPad & Surface tablets are awesome!
- Easy setup
- parts readily available
- Easily handles my 20lb scope
- Provided you get a good one, it's relatively simple to get it going

CONS
- Saddle is suspect- I upgraded to ADM saddle
- Provided weight is too freaking heavy. Need two smaller weights to balance correctly
- Doesn't come with a polar scope and it really should
- Hand controller cord is way short
- Chance of getting one with BAD 8/3 error as described in this thread


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scopenitout
member


Reged: 08/24/13

Re: CGEM-DX vs. Atlas new [Re: ScenicCityPhoto]
      #6275830 - 12/27/13 06:03 PM

Cons?
-Never had any issues with the saddle other than wishing it was "Dual V & D". And yes, an ADM could take care of that.
-Heavy for sure. And it's very stable. I'm 64 and can handle it just fine. Bought an extra CW for the C-11 Edge and full load of AP gear it has to carry.
-Polar scope? A waste of money when you can use ASPA and your camera for excellent PA's.
-The short HC cord is a damn nuisance. "Scope Stuff" makes an inexpensive extension. A must.
-8/3 error non-existent in my example and I suspect in the majority of the thousands made.


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