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Best scope for visual only on a CG-4?

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33 replies to this topic

#1 Thomas Karpf

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Posted 15 November 2022 - 10:21 PM

Mostly for deep sky, and I have perhaps $1000 to spend. I already have all of the usual accessories, so I probably needbb be only an OTA. Thanks.

Tom K

#2 Taosmath

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Posted 15 November 2022 - 10:57 PM

I think a 8" SCT would be a good choice.  Plenty of aperture for DSO's, works fine on a CG4. F10 so easy on Eyepieces. You can add a focal reducer if you are moved to go to a faster system.


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#3 Couder

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Posted 15 November 2022 - 11:06 PM

I have one of the older Celestron 4" refractors on my CG4, works great. I did make a heavy duty tripod for it.


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#4 Mark Lovik

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Posted 15 November 2022 - 11:26 PM

A 6" Newt with a coma corrector - these can be purchased under your budget and weigh about 13 pounds.  Stil have budget for a small APO refractor


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#5 Sky Muse

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Posted 16 November 2022 - 12:38 AM

This is only a prop-shot, as I've never used this telescope, a 6" f/5 Newtonian, on my CG-4(which has since been scrapped)...

 

3b.jpg

 

The telescope is supported well by the CG-4...

 

https://www.highpoin...tonian-ota-6f5n


Edited by Sky Muse, 16 November 2022 - 12:42 AM.


#6 Thomas Karpf

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Posted 17 November 2022 - 08:43 AM

Thanks all. I think I’m going to splurge a little and go with an 8” SCT.

#7 Skyfisher

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Posted 17 November 2022 - 08:57 AM

6" f6 Newtonian.  A bit awkward at first but it works.   For your budget maybe the largest Dobsonian you can get and an 80-100mm for the CG-4.



#8 SeattleScott

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Posted 17 November 2022 - 01:07 PM

Thanks all. I think I’m going to splurge a little and go with an 8” SCT.

Some say 6” SCT is the max for CG4. I suppose it depends on how picky you are about vibrations.

Scott

#9 BrentKnight

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Posted 17 November 2022 - 01:28 PM

I agree with Scott...an 8" will be pushing it with the CG4. A C6 or better yet, an AT102ED from our sponsor...
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#10 Sky Muse

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Posted 17 November 2022 - 03:47 PM

There is also the option of thinking out of the box, somewhat...

 

https://www.telescop...pe/p/131405.uts

 

That's one of the few telescopes to seriously consider from that vendor.



#11 Sky Muse

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Posted 17 November 2022 - 04:28 PM

For those larger, an EQ5-class mount is preferred, necessary perhaps...

 

finis5c.jpg

 

Now I know what happened to my CG-4, a smaller EQ3-class mount, to its tripod only.  Before and after...

 

before & after.jpg

 

A "foundation" is laid first, lastly the "roof".



#12 PeterAB

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Posted 19 November 2022 - 11:27 AM

Hi,

 

I own a CG-4 with a RA tracking motor.   I like it.   It is nice for traveling.   It is much easier to transport than the next size larger CG-5 mount that I also own.    It is good with my 127mm Maskutov.   It is just big enough to carry my AstroTech 102EDL refractor.

 

However, I would not attempt to mount my 8" SCT on it.    With all the normal accessories you need to make a telescope work, a SCT weights at, or maybe a little over, the 15 pound capacity of the CG-4.    It would be a floppy and top heavy setup.

 

Good luck,   Peter


Edited by PeterAB, 19 November 2022 - 01:31 PM.

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#13 Thomas Karpf

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Posted 19 November 2022 - 02:29 PM

I think I will now be going with the AT102ED from astronomics.
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#14 vtornado

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Posted 19 November 2022 - 04:11 PM

A 100mm ED scope is an excellent choice.



#15 Sky Muse

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Posted 19 November 2022 - 06:50 PM

Not to leave out those who prefer a simpler mount, these are the alt-azimuthal equivalents, support-wise, to an EQ-3(or CG-4)... 

 

https://www.astronom...mount-2581.html

 

...and said equivalent to an EQ-5...  

 

https://www.teleskop...adjustment.html

 

Those are just examples.

 

Regrettably, the marketplace online seems to offer fewer options for supportive, alt-azimuthal tripod-mounts, those manually-operated, when compared to equatorial mounts; even at the level of an inexpensive kit, and where one is most needed.



#16 Sky Muse

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Posted 19 November 2022 - 08:11 PM

A 4"/102mm refractor is the sweet-spot among the varying apertures of the design; not too small so as to perhaps disappoint, nor too large so as to become unwieldy, that and the mount required.

 

FS-102bb.jpg


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#17 BrentKnight

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Posted 19 November 2022 - 08:11 PM

Not to leave out those who prefer a simpler mount, these are the alt-azimuthal equivalents, support-wise, to an EQ-3(or CG-4)... 

 

https://www.astronom...mount-2581.html

 

...and said equivalent to an EQ-5...  

 

https://www.teleskop...adjustment.html

 

Those are just examples.

 

Regrettably, the marketplace online seems to offer fewer options for supportive, alt-azimuthal tripod-mounts, those manually-operated, when compared to equatorial mounts; even at the level of an inexpensive kit, and where one is most needed.

I personally wouldn't put the Twilight 1 in the same class as the CG-4.  Especially for an OTA with a long moment arm, the Twilight 1 is very weak.

 

I do wish there were more options for manual EQ and Alt/Az mounts, but I don't think the manufacturers see any profit there.  The LX70 is a great mount - no longer available.


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#18 Sky Muse

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Posted 19 November 2022 - 08:22 PM

I personally wouldn't put the Twilight 1 in the same class as the CG-4.  Especially for an OTA with a long moment arm, the Twilight 1 is very weak.

 

I do wish there were more options for manual EQ and Alt/Az mounts, but I don't think the manufacturers see any profit there.  The LX70 is a great mount - no longer available.

How would a Celestron C6 operate on a Twilight I?  Then, that is the closest we have to an equivalent.  It's the open arm of the Twilight I.  It requires strengthening, which has been performed by some, if not many, to reduce the moment-arm effect with longer-focus refractors.  

 

This is the same, manual, EQ5-class mount...

 

https://www.telescop...2160/p/9829.uts

 

...styled a bit differently, in black, and available.


Edited by Sky Muse, 19 November 2022 - 08:41 PM.


#19 BrentKnight

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Posted 19 November 2022 - 08:44 PM

How would a Celestron C6 operate on a Twilight I?

 

This is the same, manual, EQ5-class mount...

 

https://www.telescop...2160/p/9829.uts

 

..styled a bit differently, in black, and available.

How would a Celestron C6 operate on a Twilight I?

I would think it might work OK with a C6 (I wish I could say for sure, but I've never owned a C6, only a C8).  I had the mount for a while and used it with my AT72EDII (before I made that OTA an EAA telescope).  I think the major issue is with the length of the tube.  The shorter tube of the C6 might work just fine - the weight should be no problem.

 

This is the same, manual, EQ5-class mount...

OMG.  I bought my LX70 when Meade sold all of them to Woodland Hills (I believe).  I got it for $199 3 years ago.  The best deal I've ever gotten on new equipment.  It's sad what they are charging nowadays.


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#20 Sky Muse

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Posted 19 November 2022 - 09:02 PM

How would a Celestron C6 operate on a Twilight I?

I would think it might work OK with a C6 (I wish I could say for sure, but I've never owned a C6, only a C8).  I had the mount for a while and used it with my AT72EDII (before I made that OTA an EAA telescope).  I think the major issue is with the length of the tube.  The shorter tube of the C6 might work just fine - the weight should be no problem.

 

This is the same, manual, EQ5-class mount...

OMG.  I bought my LX70 when Meade sold all of them to Woodland Hills (I believe).  I got it for $199 3 years ago.  The best deal I've ever gotten on new equipment.  It's sad what they are charging nowadays.

I got just the mount-head, for $150, and everything was included, even a dovetail-bar for a prospective telescope.

 

Yes, the price-hikes, but I've always preferred my mounts to be as inconspicuous as possible whilst outdoors; like this one, and the telescope blanks out well in the dark, too...

 

kit4c.jpg


#21 BrentKnight

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Posted 19 November 2022 - 09:10 PM

I got just the mount-head, for $150, and everything was included, even a dovetail-bar for a prospective telescope.

 

Yes, the price-hikes, but I've always preferred my mounts to be as inconspicuous as possible whilst outdoors; like this one, and the telescope blanks out well in the dark, too...

 

Not me...I plaster green glow-in-the-dark tape all over the legs.  Nothing worse than tripping over the tripod...


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#22 vtornado

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Posted 19 November 2022 - 09:15 PM

I had a C6 on the TW1.  It worked ok, there was some vibration but it was tolerable and damped out quickly.

A long refractor like a 100 f/10 is not good.  Lunar focusing was tough.  If it was breezy the scope would never settle.

 

A CG4 has a higher capacity the the TW1.  The tube is supported underneath on the CG4.  It is not hanging out an an arm.

It's not only the arm that torques, but the elevation joint has some slop in it.

 

I can put a 120 f/7.5 frac on a CG4.  Its not ideal, but it would be a non starter on a  TW1.


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#23 Sky Muse

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Posted 19 November 2022 - 09:21 PM

Not me...I plaster green glow-in-the-dark tape all over the legs.  Nothing worse than tripping over the tripod...

I use a red-LED flashlight to move round and about those mounts as a result of that possibility.


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#24 Sky Muse

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Posted 19 November 2022 - 10:10 PM

I had my 4" refractor on my CG-4, once, for a prop shot only.  It's not supported well, perched atop.  I didn't dare try.  It's 4" longer, approximately, at f/8, than the AT102ED, and heavier to boot.  Although I have had somewhat better success with it mounted onto my larger alt-azimuth...

 

FS-102ib.jpg

 

...but not quite there yet.

 

That telescope was the sole reason for the getting of a larger mount.



#25 Sky Muse

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Posted 20 November 2022 - 05:36 AM

I think I will now be going with the AT102ED from astronomics.

Thomas, please let us know what you think about your new refractor, here within your thread, when you're ready, and how it fares on the CG-4.  This is your thread, and not one for the rest of us to ramble on within without your participation, particularly myself.  We'd like to see images of the refractor, along with the ensemble, too.  


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