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Mount for an 8" SCT

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#1 Gemini_87

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Posted 23 August 2009 - 12:37 AM

Well, I just got in on the deal with a Sky-Watcher, and now I was wondering if I should upgrade my mount.

I currently have a Celestron Omni mount (seen here with a scope on it) and I am hoping that this upgrade will work out, lol.

I will probably want to upgrade sometime, but I don't think it's urgent (??). Would I be looking for something like this ?

#2 Patrick

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Posted 23 August 2009 - 12:52 AM

Hi Gemini 87!

If the Celestron Omni mount you linked to can carry a 6" refractor, it should be able to carry a C8, but I wonder how well the Omni really carries such a large refractor.

When you upgrade your mount, consider what you'll be using it for. If it's just a visual setup, the requirements may be less than if you want to image.

Patrick

#3 Gemini_87

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Posted 23 August 2009 - 01:31 AM

Thanks for the reply Patrick! I will not be using the mount for astro-imaging, I just want to make sure that it's not gonna be a disaster for my new telescope when I put it on there! The astro-imaging setup will happen when I run into some serious cash. ;)

#4 Patrick

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Posted 23 August 2009 - 06:40 AM

I just want to make sure that it's not gonna be a disaster for my new telescope when I put it on there!



I should have been more clear...I don't know if it will be a disaster or not, since I don't own the Omni. You may want to do some further research on the size of the 6" refractor compared to the size of the C8. I was surprised to see the 6" refractor on the Omni, but it is just an f/5 scope, so it's not the biggest one Celestron makes. Maybe you'll get some responses from people who own the Omni.

Patrick

#5 RRPG

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Posted 23 August 2009 - 10:14 AM

I have that Celestron Omni mount with manual servos, and it carries and tracks well, I upgraded to the CG5-GT for AP work but would rather have an Atlas EQ-G if I could afford it. I have mixed results with my CG5 and alignment, some nights it works perfect, other nights who knows what goes wrong, and I just go back to the visual Land of DOBs.

#6 Luigi

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Posted 23 August 2009 - 10:16 AM

A C8 is only around 13 lb so try it on the Omni mount a see how well it works. Keeping the legs of the tripod short will help with stability. If you find it's too wobbly for your liking, then consider an upgrade.

#7 Gemini_87

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Posted 23 August 2009 - 03:19 PM

Thanks for the replies everyone.

#8 gnowellsct

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Posted 23 August 2009 - 03:23 PM

I have very different views on this topic. I think that part of the optical performance of the scope is in the mount and if you get jitter 20% of the time (wind, bumps, eyepiece changes) then even your 1/20th wave optic is 1/3 wave 20% of the time. And you might do better to have 1/4 wave and no jitter.

I would recommend the Vixen mounts for an 8" SCT if you want go-to. A Vixen Great Polaris is a great match.

If you want really, really, really solid, try the c8 on a G11. That is a reveleation.

Greg N

#9 Scott Beith

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Posted 23 August 2009 - 03:29 PM

CG-5 ASGT will be fine.
LXD-75 is another option.

#10 Doug76

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Posted 23 August 2009 - 08:09 PM

Yep, gonna use my CG-5ASGT with my new 8" SCT.

#11 gnowellsct

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Posted 23 August 2009 - 09:52 PM

CG-5 ASGT will be fine.
LXD-75 is another option.


Scott with all due respect what are we to make of you looking goofy in your pic and quoting Burke and Orwell at us. Is that the way educmated people do things in MD?

Anyhow I approve of Burke because he was, after all, a royalist.

Greg N

#12 Fred1

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Posted 23 August 2009 - 09:53 PM

Yep, gonna use my CG-5ASGT with my new 8" SCT.


Yep, you're gonna just love that set-up, Doug. :waytogo:

#13 Gemini_87

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Posted 23 August 2009 - 11:07 PM

CG-5 ASGT

Is that the "official" name of the Celestron Omni mount here?

#14 Doug76

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Posted 23 August 2009 - 11:17 PM

No, the Omni mount is the CG-4.
The CG-5ASGT is the next size up. Celestron Advanced Go To.
Pretty much the same capacity as the Orion Skyview Pro, but with built in Goto drive.

#15 Doug76

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Posted 23 August 2009 - 11:22 PM

Yep, gonna use my CG-5ASGT with my new 8" SCT.


Yep, you're gonna just love that set-up, Doug. :waytogo:


I'm certainly gonna try! :lol:

#16 Gemini_87

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Posted 24 August 2009 - 12:38 AM

One of my questions about go-to. I would like the idea of having the scope point at things automatically, but I would like to be able to turn it off. Like for visual stuff, if I wanted to find it on my own, I could. And if I wanted to use the go-to for astrophotography or something, I could. From what I heard, go-to mounts can't be manually operated? Clarification/confirmation?

#17 Luigi

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Posted 24 August 2009 - 08:34 AM

Yes, a CG5 can be manually operated either by loosing the locks and moving the scope by hand or leaving them snug and moving the scope using the hand controller buttons. I use my CG5 that way. I only do a very crude polar align and star hop from there.

The CG5 would be a fine mount for a C8 and at ~$600 new it's a great deal. There's no argument that a bigger mount would perform better, but there are tradeoffs. I had a G11 for 10+ years but decided to downsize to a CG5 when I downsized my OTAs and I'm quite satisfied with its performance with either of my ~16 lb OTAs. I leave it assembled to the tripod and carry it a soft padded bag. It's G&G compared to the G11.

#18 Doug76

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Posted 24 August 2009 - 09:51 AM

One of my questions about go-to. I would like the idea of having the scope point at things automatically, but I would like to be able to turn it off. Like for visual stuff, if I wanted to find it on my own, I could. And if I wanted to use the go-to for astrophotography or something, I could. From what I heard, go-to mounts can't be manually operated? Clarification/confirmation?


I mostly don't use the Goto feature. I align the scope mount using the computer, sure. But then it's just push the direction buttons to make it go where I want, and then it tracks. I buy Goto mounts because they don't just track, they also high speed slew, and that is something you can hardly find in add-on motor drives.

#19 Gemini_87

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Posted 24 August 2009 - 04:10 PM

One of my questions about go-to. I would like the idea of having the scope point at things automatically, but I would like to be able to turn it off. Like for visual stuff, if I wanted to find it on my own, I could. And if I wanted to use the go-to for astrophotography or something, I could. From what I heard, go-to mounts can't be manually operated? Clarification/confirmation?


I mostly don't use the Goto feature. I align the scope mount using the computer, sure. But then it's just push the direction buttons to make it go where I want, and then it tracks. I buy Goto mounts because they don't just track, they also high speed slew, and that is something you can hardly find in add-on motor drives.


Ok, so what if I see something moving across the sky and I want to follow it? Like if I'm looking for the ISS or somethign, let's say. Can you move it quickly like that with a Go-To? Would it be easier/harder with a GT than a non-GT?

#20 Scott Beith

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Posted 24 August 2009 - 04:19 PM

CG-5 ASGT will be fine.
LXD-75 is another option.


Scott with all due respect what are we to make of you looking goofy in your pic and quoting Burke and Orwell at us. Is that the way educmated people do things in MD?

Anyhow I approve of Burke because he was, after all, a royalist.

Greg N


Who said I was educmated? :shrug: :lol:

#21 Scott Beith

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Posted 24 August 2009 - 04:21 PM

One of my questions about go-to. I would like the idea of having the scope point at things automatically, but I would like to be able to turn it off. Like for visual stuff, if I wanted to find it on my own, I could. And if I wanted to use the go-to for astrophotography or something, I could. From what I heard, go-to mounts can't be manually operated? Clarification/confirmation?


I mostly don't use the Goto feature. I align the scope mount using the computer, sure. But then it's just push the direction buttons to make it go where I want, and then it tracks. I buy Goto mounts because they don't just track, they also high speed slew, and that is something you can hardly find in add-on motor drives.


Ok, so what if I see something moving across the sky and I want to follow it? Like if I'm looking for the ISS or somethign, let's say. Can you move it quickly like that with a Go-To? Would it be easier/harder with a GT than a non-GT?


CG-5 is rated at 4 degrees per second slewing rate in both RA and DEC.

#22 Doug76

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Posted 24 August 2009 - 04:43 PM

CG-5 ASGT will be fine.
LXD-75 is another option.


Scott with all due respect what are we to make of you looking goofy in your pic and quoting Burke and Orwell at us. Is that the way educmated people do things in MD?

Anyhow I approve of Burke because he was, after all, a royalist.

Greg N


Who said I was educmated? :shrug: :lol:


Or from Maryland? He's a newcomer there. Used to be in the Deep South, you know, God's Country.
You know what we say, "American by birth, Southern by the grace of God".

#23 Doug76

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Posted 24 August 2009 - 04:44 PM

Ok, so what if I see something moving across the sky and I want to follow it? Like if I'm looking for the ISS or somethign, let's say. Can you move it quickly like that with a Go-To? Would it be easier/harder with a GT than a non-GT?


In a word, Yes.

#24 hydrogia

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Posted 24 August 2009 - 09:06 PM

... and beyond. A GOTO moves considerably quicker than that too. Almost fast enough for tracking a low flying airplane moving across the sky.

I haven't tried it yet, but I think even my GM8 moves fast enough to track satellites and it doesn't have GOTO. 32X HST (High Speed Transfer) seems fast enough to track satellites, and that speed is something like level 3 speed on the CG5 (speeds are 1-9).

My issues with the CG5 came from it's high speed not being fast enough, so undoing the clutches and doing it pushTo style became the norm. Also after a little while using the hand control to star hop (without undoing the clutches) the drives would develop some serious backlash.

I say if you get a CG5, get a used one because you will lose lots of money should you decide to sell a new one. Learn from my mistake. They're about $350 used and most LNIB.

Good luck!






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