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Equipment Discussions >> Mounts

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Bill McNeal
sage


Reged: 10/07/07

Recommend a mount for a new guy.
      #5960701 - 07/08/13 03:05 PM

Hello, I have a C4R refractor and looking for a replacement mount. Current equatorial mount is semi-broken at the OTA attachment but could be patched up, but I'm considering upgrading. The features are a bit confusing. A few questions:

1. If I get a drive motor, is there universal compatibility with any mount as long as its equatorial? Or is it better to get both motor and mount as a combo?

2. GoTo seems a lot more expensive. Should I get that as an add-on, or is it better to get it as a combo with mount and motor?

Any specific recommendations on brands and model numbers would be highly appreciated!


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Mike X.
scholastic sledgehammer


Reged: 06/28/10

Loc: Greece-Athens and Rome-Italy
Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5960876 - 07/08/13 04:42 PM

Hello,i guess it would probably cost you less at the end if you could purchase a goto mount instead of just the mount and then the motors and after that the goto.

Edited by Mike X. (07/08/13 04:43 PM)


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Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Recommend a mount for a new guy. new [Re: Mike X.]
      #5960963 - 07/08/13 05:35 PM

I am guessing your C6R is on a non-goto CG-5 mount based on what I see in this manual here on Celestron's site. If that is so and if I understand you right that the dovetail bracket at the top of the mount is what is broken then you might look at ADM's dovetail bracket upgrade part (VSAD-VM). It is only $99 and really a much nicer part then the original so that is perhaps your least expensive way to get up and running again.

If you wanted to add tracking (but not go-to) to your CG-5 I *THINK* this one here would work given the extreme similarity of the skyview pro and CG5 mounts.... but perhaps it is worth having that confirmed by someone else before purchasing.

However if you want to get goto I would agree that replacing the mount entirely for a unit with go-to would be the least expensive option. Right now the go-to version of your CG-5 (the CG5-ASGT) is quite inexpensive at a bunch of places as it is in the process of being replaced with the A-VX mount. There are of course lots of other options in go-to monuts as well depending on your budget and what (if anything) you would like to do other then view through your C6R scope, however none of the cheaper ones will likely be as solid as a CG5-ASGT so if budget is a primary concern that is where I would look. If you are looking for a more physically solid mount something like the Celestron Advanced-VX, iOptron ZEQ25 would be a small step up from the CG-5 and the iOptron iEQ30, iEQ45, Celestron CGEM, or Orion Atlas EQG would be the fairly big step above.


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Bill McNeal
sage


Reged: 10/07/07

Re: Recommend a mount for a new guy. new [Re: Falcon-]
      #5962690 - 07/09/13 05:55 PM

Thanks Mike and Falcon.

To clarify. I believe it is a CG-5 mount. One of the two screw attachments to the OTA is broken off, so a replacement mounting plate unfortunately won't work since it won't have one of the two mount attachments to affix to.

I will look into the CG-5 ASGT. What about the A-VX is better to justify the increased expense?

Also, it is possible to get a GoTo without a tracking motor?


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Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5962820 - 07/09/13 07:23 PM

Quote:

Also, it is possible to get a GoTo without a tracking motor?



No, but it is possible to get "push to" or Digital Setting Circles (DSC) - they are same thing. With those you put encoders on the two axis of the mount so a small handbox can track where the scope is pointed and guide you to find objects as you manually move the mount. I use this currently on my CI-700 mount.

However - the cost of a new DSC system is nearly identical to a CG-5 ASGT and I can tell you from experience that the ASGT's goto system is a lot more accurate then the NGC-MAX DSC system I use! So.... ya, I would forget that option at the price range you are looking at (it makes more sense when updating a very large older mount).

Quote:

I will look into the CG-5 ASGT. What about the A-VX is better to justify the increased expense?




It is sorta the other way around actually. The Advanced VX mount is the updated replacement of the "Advanced Series GT" (CG5 ASGT). A few months ago the CG5 ASGT was the same price the AVX is now! So right now the CG-5, while they last, are a very good deal.

As for the differences, the AVX is a physically slightly more robust mount with a lot of seemingly small changes in design that add up to a nice upgrade. It seems to be a worthy sucessor to the respected CG5. (This is based on what I have been seeing others report about the AVX as I have not seen one in person yet myself)

Quote:

To clarify. I believe it is a CG-5 mount. One of the two screw attachments to the OTA is broken off, so a replacement mounting plate unfortunately won't work since it won't have one of the two mount attachments to affix to.




I have to admit I am still not entirely clear on what is broken. Here is what I would expect to see:

- The scope's tube itself is held in the grip of two "Tube Rings" that go entirely around the tube in two place.
- The two Tube Rings are bolted to a metal bar "the Dovetail Bar" the dovetail bar is probably something like 8" or 12" long.
- On the top of the mount's DEC axis there is a "Dovetail Clamp" where the Dovetail bar is held in place by sloping sides of the casting on one side and a big screw on the other side.

I was assuming the Dovetail Clamp had failed. Are you saying that one of the Tube Rings is broken or are you saying that the Dovetail bar is damaged, or is it something else entirely?

If it is ether the Tube Ring or Dovetail Bar that is damaged both can be replaced fairly easily, and in fact you would need to replace those regardless of if you replace the mount or not.

Perhaps you could post an image of the failed part?


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Bill McNeal
sage


Reged: 10/07/07

Re: Recommend a mount for a new guy. new [Re: Falcon-]
      #5963027 - 07/09/13 09:32 PM Attachment (53 downloads)

I took a couple of photos. Here is the full assembly. The top of the front tube ring is missing a screw and washer. Is that a problem, and if it is, how should I fix it?

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Bill McNeal
sage


Reged: 10/07/07

Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5963028 - 07/09/13 09:34 PM Attachment (33 downloads)

Here is the top down view of the mount, with the OTA removed. The front screw attachment has snapped off. What would you do in my situation?

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orlyandico
Postmaster
*****

Reged: 08/10/09

Loc: Singapore
Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5963082 - 07/09/13 10:12 PM

I think a new tab can be MIG or TIG welded where the original one broke off. These things are aluminum so arc welding won't work. So if you can find someone local who can weld a new tab on for beer money, go for it. But if the welding would cost too much... you'd be better off buying.

The mount in its current condition is worth probably $50 - $100 tops, so not worth selling.

And.. I don't think it's a CG-5. Probably a CG-4. The CG-5's all came with a Vixen dovetail clamp. What you have doesn't have any form of dovetail clamp.


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Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5963147 - 07/09/13 10:45 PM

Interesting! Rather then a dovetail bracket it uses the older method of a direct adaptor. Perhaps the forum historians might be able to best place this mount, but from some google image searching looking at various mounts I think this is an early CG-4 mount (not a CG-5).

For what it is worth the CG4, CG5, CG5-ASGT, Orion Skyview Pro, and Skywatcher EQ5 and EQ3 are *all* clones of the Vixen Super Polaris/Great Polaris mounts, so they all look rather similar! In this case though the CG4 has a lower payload capacity then the CG-5 and (apparently) originally did not use a dovetail clamp.

Well ok. As it looks like it will not accept the CG-5 dovetail clamp upgrade I originally recommended I see three options:

1) try and find another CG-4 or EQ-3 damaged in some OTHER way for parts so you can replace the broken scope adaptor with a dovetail adaptor (and then get a dovetail bar for the scope).

2) Kludge it - get a short metal bar and drill and tap mount points for it on the top of the mount to give your tube rings a new place to mount.

3) Sell the mount as a project for someone else to fix/kludge and get a new mount.

The Classifieds section here might be able to help with either #1 or #3...


If you go with #3 here are some things to expect: The CG-5 ASGT will be a little bit heavier then your existing mount but also more stable (less prone to vibrations). This is both due to the mount construction itself being a bit more robust and the tripod being a MUCH better one with nice stainless steel legs. Also since the new mount will use a dovetail bar it is *easy* to remove the scope from the mount so the whole thing is more portable (easier to carry as two or three parts instead of one). Plus... goto and tracking!


A couple of reference points:
- This is the current version of what I think your mount is: Celestron Omni CG4$290 (tracking drive here for $140)
- This is the go-to equipped last generation of CG-5: Celestron CG-5 ASGT$595 (on sale due to being discontinued)
- This is brand new the replacement for the CG-5: Celestron Advanced VX$719 (on sale)
- If you want to keep physical weight of your equipment low you might consider this alternative: iOptron ZEQ25$799

In my opinion best bang-for-the-buck is the CG-5 ASGT, best performing mount likely the AVX.


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Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Recommend a mount for a new guy. new [Re: Falcon-]
      #5963152 - 07/09/13 10:47 PM

That is what I get for being long-winded, orlyandico beat me to it. He has a good point though, know anyone who can weld cast aluminum?

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Bill McNeal
sage


Reged: 10/07/07

Re: Recommend a mount for a new guy. new [Re: Falcon-]
      #5963231 - 07/09/13 11:30 PM

Thank you again orlyandico and Falcon. You're right it could be a CG-4.

I'm now leaning to one's those models you listed, Falcon.

Do I have to worry about the missing washer and screw in the front tube ring?


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Mkofski
Pooh-Bah
*****

Reged: 07/19/11

Loc: Greenfield, Indiana, USA
Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5963253 - 07/09/13 11:41 PM

Quote:

Thank you again orlyandico and Falcon. You're right it could be a CG-4.

I'm now leaning to one's those models you listed, Falcon.

Do I have to worry about the missing washer and screw in the front tube ring?




You don't need to worry about that. It is for attaching other things to the top of the scope.


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Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Recommend a mount for a new guy. new [Re: Mkofski]
      #5963294 - 07/10/13 12:00 AM

Quote:

Do I have to worry about the missing washer and screw in the front tube ring?




If you are talking about the wide black "washer" and screw on the top of the ring, no. That is actually for piggyback mounting a camera (or anything else relatively lightweight that mounts with a tripod (1/4-20) bolt). It only ever had the one.

Something you will need though is a dovetail bar (the tube rings get mounted to the dovetail bar). You can get those from places like this or this.


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Bill McNeal
sage


Reged: 10/07/07

Re: Recommend a mount for a new guy. new [Re: Falcon-]
      #5963307 - 07/10/13 12:10 AM

Thanks. So the CG-5 ASGT doesn't include the dovetail bar?

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Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5963320 - 07/10/13 12:16 AM

Hmm.. now that you mention it I mine *did* come with a short dovetail bar just for conversions like you are doing. That was in 2009 so it is possible they may not come with one now.... Perhaps someone who has purchased a CG5 recently could chime in?

(Most mounts do not come with a dovetail bar as those are usually included with the scope.)


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Bill McNeal
sage


Reged: 10/07/07

Re: Recommend a mount for a new guy. new [Re: Falcon-]
      #5963370 - 07/10/13 01:01 AM

From what I've seen, the A-VX has "periodic correction," "transmeridian imaging" and "polar alignment", that the CG-5 ASGT lacks. How important are these features for astrophotography?

Someone told me that "astrophotography" is an expensive word. I love your website pictures, Falcon. How much would a setup like yours cost to take those pictures?


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Falcon-
Post Laureate
*****

Reged: 09/11/09

Loc: Gambier Island, BC, Canada
Re: Recommend a mount for a new guy. new [Re: Bill McNeal]
      #5963492 - 07/10/13 04:23 AM

Quote:

From what I've seen, the A-VX has "periodic correction," "transmeridian imaging" and "polar alignment", that the CG-5 ASGT lacks. How important are these features for astrophotography?




Periodic Error Correction: In my opinion on a mount of this class this does not matter all that much. Autoguiding does the job instead.

Transmeridian Imaging: This can be very useful. With both my CG-5 and CI-700 once a target reaches the center of the sky I have to stop imaging and switch everything around to the other side, make sure I have the target back in the same framing, etc. Not *that* big of a deal, but still... being able to image even a bit past meridian is a nice bonus for imaging.

Polar Alignment: Very important feature for getting longer exposures. However the CG-5 also has a polar alignment routine built in to it's hand-controler (or at least for every CG-5 sold for quite a number of years now). Unless there is something else I am unaware of both mounts should be somewhat equal here except that they improved the mechanical design of the alignment adjustments in the AVX.

As I understand it they also improved a lot of little things that add up to a more stable and smooth performing mount. Not enough to call the AVX a high-end mount, but all good improvements none the less! (It is worth noting that "high end" mounts start at $3,000 and go to $20,000+ depending on where you draw the line)

Quote:

Someone told me that "astrophotography" is an expensive word.



It can be. Depends on how far you want to take it. However you CAN do some nice AP work with relatively inexpensive equipment!

Quote:

I love your website pictures, Falcon. How much would a setup like yours cost to take those pictures?



Thanks! Those pictures span quite a bit of time. As a near zero budget astrophotographer I have build up my equipment gradually in small chunks. At the start I was using a very beat up 30+ year old EQ-2 mount (much wobblier and less consistent a performer then your CG-4, only I had a RA-only tracking motor). With that, an old Canon DSLR and some wide-angle lenses I was able to get these results. However being able to skip the frankly terrible EQ2 and go right to a CG5 or AVX would be a GOOD thing for you! Certainly those mounts are less of a strain on one's patience!

So my first serious purchase made for astrophotography was my CG-5 ASGT. The CG5 is not perfect, like I said not a high-end mount, but it was WORLDS better then the EQ2 and with a bit of time and effort I got quite a lot of results from it! These images are all taken using my CG5, some with camera lenses, some though telescopes. Initially those where taken unguided (without a guide-camera and guide-scope). If you do a search for "unguided" on my site you will find a bunch of those.

Eventually I did get a guide camera and started to push for very long exposures. This is where I started to run into the limits of the CG-5 as I had some trouble getting it to behave consistently over very long sets of long exposures (several hours of 10-minute exposures). The mount could do it, but it required babysitting and tweaking of settings. An AVX or ZEQ25 will perform better here.

So to directly answer your initial question to get the full rig I have now (2 imaging scopes, 6 camera lenses, two modified DSLR cameras, a guide-camera and 50mm finder-guide scope, two mounts and a bunch of misc bits and bobs) would be something on the order of $5000. You can *easily* spend much more on astrophotograph gear should you want to - in fact some people would consider $5000 only a starting point for the mount alone! HOWEVER if you already have a DSLR camera (whatever the make/model) you CAN start imaging with just a mount and whatever camera lenses you already have. I did! Even if you do have a camera yet an older Canon DSLR like the 450D (Rebel XSi) or 1000D (Rebel XS) can be had for quite cheap used these days - watch your local Craigslist!

I am rambling on here a bit but the point is Astrophotography can be expensive, but it can also be done on the cheap, and it can be fun so whatever mount you get put a camera on it and give things a try!


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orlyandico
Postmaster
*****

Reged: 08/10/09

Loc: Singapore
Re: Recommend a mount for a new guy. new [Re: Falcon-]
      #5963499 - 07/10/13 04:42 AM

I have to chime in here, having gotten nickel-and-dimed on various mounts and stuff.

Falcon reports that he's spent on the order of $5000.

That will get you a used Mach1, which is the best mount in the world that weighs less than 35 pounds.

My experience has been, if you decide to get serious, you should skip the incremental upgrades and either bite the bullet right away, or stick with what you have until you can buy the best.

So.... my suggestion would be to get a CG-5 or AVX, use it for a few years, and then if you really like doing astrophotography, skip the CGEM/Atlas, CGE, G11, etc. and go straight for Astro-Physics or Software Bisque.

You would actually end up saving money in the long run.


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cn register 5
scholastic sledgehammer


Reged: 12/26/12

Re: Recommend a mount for a new guy. new [Re: orlyandico]
      #5963531 - 07/10/13 05:22 AM

PEC on the AVX may work better than you think. My AVX has an uncorrected error of just over 30 arc seconds P-P and with PEC training that came down to 2.6 arc seconds RMS. They have got the gear box sorted so all the gears are integer ratios of the worm rotation period.

That sort of error should be small enough that you can image without guiding as long as you keep the focal length down, have a reasonably good polar alignment and aren't too ambitious with the exposure length.

Of course you really need guiding to do the PEC training so you may as well continue guiding, that's where I am.

Chris


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WadeH237
Pooh-Bah


Reged: 02/24/07

Loc: Snohomish, WA
Re: Recommend a mount for a new guy. new [Re: orlyandico]
      #5963835 - 07/10/13 10:50 AM

Quote:

My experience has been, if you decide to get serious, you should skip the incremental upgrades and either bite the bullet right away, or stick with what you have until you can buy the best.

...

You would actually end up saving money in the long run.




This advice is gold.

I've gone down a similar path of upgrades. I stopped tallying up my total investment a long time ago because the number is much larger than what we are talking about here.

I started imaging back in the late 90's with a Celestron Ultima 2000. Along the way, I've also tried the CG5, the LXD75 and the CGE. I tried Celestron's Fastar and Starizona's Hyperstar. I've used one shot color CCDs, DSLRs and mono CCDs with filters.

I spent about 10 years with the CGE as my primary imaging mount. During that time, the primary metric that I used to gauge quality was the roundness of stars. The CGE is actually a pretty good imaging mount, but there is a bit of an art to getting it to perform at its best. I learned that it was normal to spend a bit of time to tweak things to get guiding spot on.

For the last 5 years or so, I started dreaming about stepping up from the CGE to a premium imaging mount. The two leading contenders were the Bisque mounts and Astro-Physics. I believe that Takahashi can play in this group as well, but their mounts just didn't call to me.

A couple of years ago, I took the plunge and got on the list for a new AP mount. I happened to sign up for a model that was discontinued shortly after, so I had to wait a bit over a year for the new model to become available. Finally, in December last year, I got my new mount.

From day 1, this was a completely different game. There was a short learning curve to figure out how to set up the mount and how it worked. Most of this, I was able to do by reading documentation and forums before the mount even arrived.

After a couple of nights trying things out, the mount just disappeared. By this, I mean that if some problem happens, it's not the mount. Remember above, where I said that my main metric used to be roundness of stars?
Well, with the AP mount, the stars are round. Always. Long exposure? Round stars. Long focal length? Round stars. Guiding through a narrow band filter with 60 second guide exposures? Round stars. Guide software fails to get a lock and the 10 minute exposure goes unguided? Round stars.

I now look at FWHM (full width half maximum - a measure of the size of stars) as my primary metric. I can tell at a glance variations in seeing from one night to the next. I now know where areas in my yard have local seeing variations due to heat radiation during the night. I've gone back and completely revised how I use FocusMax to get optimal focus, because the mount no longer hides issues. Collimation matters.

The difference in image quality is astonishing. The only downside is that my own image processing skills have now been exposed as the weakest link by far in my workflow. This isn't really a downside, since I am well aware of my limitations here. One of my goals in upgrading was to free myself from dealing with image capture and start putting my efforts into processing.

Sorry for the long winded post, but it's been said that the 3 most important things in astrophotography are the mount, the mount and the mount. I just wanted to ramble for a bit on what that really means, at least to me.

And like the above advice, I would have spent much less in the long run if I had acquired a great mount earlier. I am finding myself with too much stuff now and am looking to pare down my equipment list.

For someone with a serious interest in astrophotography, I don't necessarily recommend diving into the premium mount market. There are a few good entry level mounts. The Atlas and CGEM are proven here. The AVX is new, but looks very promising. The CG-5 is pretty good with shorter focal lengths. I would suggest starting with one of those. Try imaging for a year or two. Once you know that you're really into it, I would say that's the time to buy all the premium mount that you can afford. You can recover some of the cost by selling the first mount. You'll end up spending less in the long run than you would by working your way up through upgrades, or buying gadgets and gizmos to try and make your entry level mount perform like a premium mount.

I hope this has been interesting,
-Wade


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