31 replies to this topic

[Star1Fun]

I have been pondering a good grab and go set up to compliment my Nexstar SE mount. I am pondering what a good alt/az mount would be for a C6 OTA So I could use the 6inch SCT scope as a GOTO set up as well as a scan the night sky alt/az scope as well. I am also really pondering getting an Orion ST80 f/5 refractor for its wide angle scanning the heavens scope. I have always wanted a scope that is super wide and good to look for star clusters one of my favorite things to view. Or just a scope that takes a few minutes to set up for ease of use when I don't want set the SE mount up. I really just wanna search for objects Old School maps and flash light in hand. The SE mount is awesome as it finds stuff for you but I also love the hunt for objects and reward of finding an object in the night sky.

 

Any thoughts or ideas on the C6 for either GOTO mode or Alt/az mode. When I buy a second wide field scanning scope I feel my curiosity will have no boundaries. I have seen people use the Orion ST80mm scope on a Celestron SE mounts on You Tube. Thats where my reasoning would be great as well to use the SE mount for 2 different scopes or buy an ALT/AZ mount for either scope as well. 2 OTA as well as 2 Mount systems. I prefer to not go any larger than a 6 inch SCT scope I prefer smaller scopes do to the fact I will use a small scope 100% more than a larger scope.  

 

[Bob Campbell]

I have been pondering a good grab and go set up to compliment my Nexstar SE mount. I am pondering what a good alt/az mount would be for a C6 OTA So I could use the 6inch SCT scope as a GOTO set up as well as a scan the night sky alt/az scope as well. I am also really pondering getting an Orion ST80 f/5 refractor for its wide angle scanning the heavens scope. I have always wanted a scope that is super wide and good to look for star clusters one of my favorite things to view. Or just a scope that takes a few minutes to set up for ease of use when I don't want set the SE mount up. I really just wanna search for objects Old School maps and flash light in hand. The SE mount is awesome as it finds stuff for you but I also love the hunt for objects and reward of finding an object in the night sky.

 

Any thoughts or ideas on the C6 for either GOTO mode or Alt/az mode. When I buy a second wide field scanning scope I feel my curiosity will have no boundaries. I have seen people use the Orion ST80mm scope on a Celestron SE mounts on You Tube. Thats where my reasoning would be great as well to use the SE mount for 2 different scopes or buy an ALT/AZ mount for either scope as well. 2 OTA as well as 2 Mount systems. I prefer to not go any larger than a 6 inch SCT scope I prefer smaller scopes do to the fact I will use a small scope 100% more than a larger scope.  

why not a c5 (not c6) switchable with a 80mm achromat mounted vixen-style on a skywatcher az-gti?

 

c5 much lighter, less of a strain, shorter FL compared to a C6, c5's very well regarded.

 

If you already have the C6, that would work well, but it is pushing the limits of that mount.

 

Either config would be very quick to setup and use, and then it would just be the thermal equilibration of the SCT that would be the limiting factor.

 

Bob

[luxo II]

It is possible.

 

For visual, push-to is better than GOTO IMHO - quicker to set up, no batteries apart from charging the Nexus, and the "handset" is SkySafari on a phone, though you're welcome to use your maps without Nexus if you wish.

 

My large travel rig is a push-to one, 6" mak + StellarVue M2C, on a Berlebach UNI 8 tripod, with Nexus II and encoders. The whole shebang - scope, M2C, tripod, eyepieces and a diagonal wrapped in bubblewrap will fit in a medium suitcase - with a baggage strap - as the whole thing weighs in at 26kg.

 

I've flown with this and if organised beforehand the excess baggage costs aren't prohibitive (like $50 each way) if you travel light.

 

While a 6" SCT would be lighter than my mak, the NexStar mount is probably heavier and it needs a pile of batteries. The other problem is the length of the tripod when packed - it won't fit in a suitcase but you could tie the legs with bungee and put it naked as "oversize luggage", no harm will come to it.

 

https://www.cloudyni...-for-the-night/

 

I'm doing outreach tonight for a remote pacific island community (!) among the palm trees, coral reef, lagoon and its looking really nice this afternoon, so hopefully I can post a shot "on location"... would be Bortle 1 if they hadn't picked the week of the full moon, darn it.

 

Living the dream !

Edited by luxo II, 22 February 2024 - 11:48 PM.

[c2m2t]

Hi Star1Fun!

I think you want to consider what it is that you will be looking at during your Grab n Go sessions. The SCT's are very fine scopes but the traditional F10 versions suffer from one problem...they have a fairly narrow field of view that is great for observing planets, details on the moon, double stars, the brighter smaller galaxies and globular clusters. You can purchase a purpose meant focal reducer that will increase the apparent field by about 30% but the field is still pretty narrow. I have both a 9.25" Celestron and a 12" Meade, but their use is fairly focused on a small range of targets.

 

The wide field of the Orion ST80 is a great companion scope from the point of view of wide field, but I would highly recommend that you save your money until you can manage a scope with better optics. My ST80 is good in the central 50 percent of the field but as you approach the outer 1/3 of the diameter of the lens, there is quite a bit of distortion. You can overcome that with a field flattner but this is just another expense and more glass to reduce the light getting to your eye. A new ST80 sells around $180.00 US plus taxes...its purchase will likely not break the bank but if you want to do some serious observing and maybe some astro-photography in the future, I believe it would be wise to wait while doing a bit more research for a scope with better optics. You will find the ST80 occasionally, used, here on CN. 

 

With regard to mounts, grab and go often means that the observing window is shorter. An alt-az mount has much to offer for these often shorter and suddenly organized observing sessions. 12 years ago, I purchased the Swiss made version of the William Optics Ezi-Touch mount. It is a side by side setup that carries two scopes. It has been my preferred mount for my annual Messier Marathons. For the MM's. I setup with two 120mm scopes, one at F5 and the other at F8.2. The F5 scope is a Skywatcher 120x600 achromat that I use as a wide-field scope to view all the open clusters and larger galaxies on Messier's list. The Orion 120x1000 is also an achromatic to which I add a binoviewer with 16mm wide-field eyepieces that increases the magnification substantially over the SW 120x600 with a 22mm Nagler EP. 

 

In comparison, your choice of the 6" SCT and the Orion ST80 would provide a very similar setup. To be honest, I really love my SW 120x600...yes it has a bit of violet fringing on the very brightest of objects, but for its cost, it provides some exceptional views along with the 22mm Nagler.

 

The bonus of having two scopes side by side with different levels of magnification,is that you find yourself not having to switch in eyepieces as often...so nice to be able to compare views by just moving between the two scopes.

 

There are other side by side mounts on the market...again you want to do some research. If the hobby really grows on you, you are likely going to have mounts in both the alt-az and GEM in a goto version. I know the impulse to buy is huge...I won't divulge as to how many scopes and mounts I have...but I strongly suggest that you do your homework and get out to some star parties to "kick tires"...so to speak.

 

Good luck and I wish you great joy and satisfaction as you venture down this road!!

 

Cheers, Chris.

[luxo II]

In my 6” f/12 with a Brandon 48mm, the field of view is over 1.5 degrees. Plenty IMHO, and easily aligned on targets without a finderscope. Using the encoders and M2C mount the push-to accuracy is better than 10 arc minutes, and it’s good enough to track a planet at 220x while someone else is looking through it.

[Jon Isaacs]

 

The wide field of the Orion ST80 is a great companion scope from the point of view of wide field, but I would highly recommend that you save your money until you can manage a scope with better optics. My ST80 is good in the central 50 percent of the field but as you approach the outer 1/3 of the diameter of the lens, there is quite a bit of distortion. You can overcome that with a field flattner but this is just another expense and more glass to reduce the light getting to your eye. A new ST80 sells around $180.00 US plus taxes...its purchase will likely not break the bank but if you want to do some serious observing and maybe some astro-photography in the future, I believe it would be wise to wait while doing a bit more research for a scope with better optics. You will find the ST80 occasionally, used, here on CN.

 

Chris:

 

What you are seeing in the outer field is field curvature probably combined with some off-axis astigmatism from the eyepiece.  The curved focal plane in inherent in any short focal length refractor, it has nothing to do with the quality of the optics, it depends on the focal length of the scope.  An ST-80 with a 1.25 inch eyepiece like a 32mm Plossl or 24mm SWA will focus about 0.7mm inward of the center focus at the edge.  This seems like a lot but it is actually not too bad.  When you add a 2 inch focuser to an ST-80, then a 30mm UWA like the 31mm Nagler focus about 1.7mm inward of the center.. Field curvature quickly disappears with narrower fields of view.

 

F/5 is pretty fast.  Many eyepieces exhibit off-axis astigmatism in the outer field at faster focal ratios.  An eyepiece like the 24mm Panoptic is very sharp at F/5 so all you will see is the field curvature of the telescope.  Eyepieces like the 25 mm Paradigm are not so well corrected at F/5 so what you see is the curved focal plane of the telescope combined with the off-axis astigmatism of the eyepiece.  

 

Getting a sharper field begins with the eyepiece.  

 

An ST-80 with a 32mm Plossl or 24mm SWA (24mm Panotic etc) will provide a 3.9 degree TFOV, plenty wide for most needs.  That is the beauty of an ST-80, it provides nice, wide fields with 1.25 inch eyepieces.

 

An ST-80 and a C-6 would make a nice pairing, one for higher magnification views, one for wide field views.  One could "upgrade" to an 80mm F/7 ED refractor like the AT-80ED and get even wider fields and better performance at higher magnifications but that gets expensive fast, 2 inch eyepieces and a 2 inch diagonal.

 

Jon

[quilty]

There's no more scope a grab and go than a 5-6 inch Mak or SC

Edited by quilty, 23 February 2024 - 04:14 AM.

[tturtle]

I think the best way to mount a C6 for grab and go is to use a high quality fluid head mount.  About 5 years ago I got rid of my CGEM Go To mount for my 9.25 SCT in favor of a fluid head and have been very happy ever since as it really simplifies my observing sessions with this scope. The key is to research fluid heads and understand that the budget ones are largely junk.  You want one from a serious manufacturer and it needs to have internal counterbalancing springs to eliminate the need for counterweights. This makes a very nice push to rig that I often use at 300x magnification, since the movements are really smooth and backlash free. 

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[Brollen]

I think the best way to mount a C6 for grab and go is to use a high quality fluid head mount.  About 5 years ago I got rid of my CGEM Go To mount for my 9.25 SCT in favor of a fluid head and have been very happy ever since as it really simplifies my observing sessions with this scope. The key is to research fluid heads and understand that the budget ones are largely junk.  You want one from a serious manufacturer and it needs to have internal counterbalancing springs to eliminate the need for counterweights. This makes a very nice push to rig that I often use at 300x magnification, since the movements are really smooth and backlash free. 

I  would agree with the fluid head mount suggestion. I have a Manfroto 502a fluid head on an Orion Paragon Plus tripod and the pairing works very smoothly for my smaller refractors (up to my 90mm) and SCTs (up to my C6 & M6). A quality fluid head moves very smoothly and with a center post tripod you can easily raise and lower the scope to comfortable viewing positions. I love using my setup. I do use a small counter weight at the front of my SCTs when binoviewing to compensate for all the weight at the rear of the scope - ie, mirror, bino, eyepieces, etc. With a C6 and a quality 50 or 60mm finder scope, I especially like the ones that accept EPs, you would have a portable setup that provides wide and power views.

[tturtle]

Yeah the photo of my rig shows a counterweight which I need when I use the very heavy binoviewer, but if I’m in mono it works fine without it and makes the setup that much easier and quicker to take out. 
 

I  would agree with the fluid head mount suggestion. I have a Manfroto 502a fluid head on an Orion Paragon Plus tripod and the pairing works very smoothly for my smaller refractors (up to my 90mm) and SCTs (up to my C6 & M6). A quality fluid head moves very smoothly and with a center post tripod you can easily raise and lower the scope to comfortable viewing positions. I love using my setup. I do use a small counter weight at the front of my SCTs when binoviewing to compensate for all the weight at the rear of the scope - ie, mirror, bino, eyepieces, etc. With a C6 and a quality 50 or 60mm finder scope, I especially like the ones that accept EPs, you would have a portable setup that provides wide and power views.

[Brent Campbell]

Unless price. Is the biggest concern I would not go with an ST80.  It amazes me that people spend good money upgrading ST 80s with better focusers which puts the total outlay into a  the price range of nice 70 mm or 80 mm Ed refractor.  To me it makes an good economic case against an st80.
 

The Astro tech 72 edt https://www.astronom...6.html?___SID=U would make a fine grab and go for not much more money.  When you consider the cost of a diagonal a 2 inch eyepiece and a mount the total outlay isn’t much more to get better color correction and a scope that could be used for imaging if you wanted.  The Astro tech also comes stock with a 2 inch focuser which as I said is an add on to an st80.

Edited by Brent Campbell, 23 February 2024 - 09:00 AM.

[Jon Isaacs]

I think the best way to mount a C6 for grab and go is to use a high quality fluid head mount.  About 5 years ago I got rid of my CGEM Go To mount for my 9.25 SCT in favor of a fluid head and have been very happy ever since as it really simplifies my observing sessions with this scope. The key is to research fluid heads and understand that the budget ones are largely junk.  You want one from a serious manufacturer and it needs to have internal counterbalancing springs to eliminate the need for counterweights. This makes a very nice push to rig that I often use at 300x magnification, since the movements are really smooth and backlash free. 

 

 

As an engineer, simplicity is a virtue. 

 

A fluid head is designed to be used with cameras at angles near the horizon. The camera is mounted above the axis of rotation of the altitude axis. This means the camera becomes more and more unbalanced as the elevation angle is increased.  To attempt to deal with this imbalance, viscosity, springs and sometimes counterweights are needed. 

 

When a telescope is mounted on a fluid head,  this becomes a larger issue because a telescope mount needs to optimized for viewing at high elevation angles.. 

 

The complexity of this solution can be avoided simply by mounting the telescope so the rotational axis of the altitude axes passes through (or near) the center of gravity of the telescope. The telescope balances itself so counterweights, springs and viscosity are unnecessary. 

 

This is the basic principle of the fork mount, it's a self balancing design. Fork mounts can support the scope from one side or from both sides. With larger scopes, both sides are generally used for added support, LX-200 mounts for example. The Dobsonian mount is a fork mount that supports the scope from both sides.

 

For smaller scopes, mounts that support the scope from one side are more that adequate and make mounting using a Vixen Dovetail simple and easy.  Mounts like the Vixen Portamount, the Explore Scientific Twilight 1 and Twilight 2, StellarVue mounts, Discmounts and many others are single sided fork mounts that provided so!I'd, smooth, tracking over a wide range of magnifications.

 

Some added slow motion controls to provide precise slewing, centering and tracking at high magnifications.  I prefer slow motion controls.

 

I've never owned a C-6 but I've owned three C-5s, two were mounted on a Vixen Portamount, one was mounted sidesaddle on a Bogen 3047, a balanced design. 

 

For a C-6, I'd use a Portamount or my Astro-Tech Voyager from 15 years ago. I have a Bogen fluid head.. 

 

Jon

[c2m2t]

Hi Jon!

Thank-you for that insight...I will definitely pay more attention next time I have the ST80 on the mount and will experiment with many more eyepieces. I will endeavor to do that sooner than later. That being said...and having done quite a bit of A-focal imaging through both the ST80 and the SW 120x600, the SW 120x600 is far superior...but the larger optics will likely have much to do with that. The ST80 has spent literally a thousand hours on my double star imaging scope as my finder and casual observing scope during the imaging sessions. I am pairing it up with a 32mm Celestron plossl and in my humble opinion, the outer third of the field is mushy. It would be very instructive to be able to add my 22mm Nagler to the ST80 but alas, the ST80 does not have a 2" focuser. The 22mm Nagler combined with the SW 120x600 has provided some of the most spectacular views I have had at an eyepiece...sharp to the limits of the field...you almost feel like you are immersed in the star field.

 

For those checking out the used market, the old, no longer made Stellarvue 80mm Nighthawk, at F6, is a wonderful small scope. The only issue with it, it weighs a ton...likely enough aluminum in the OTA for 2 scopes. It is an achromat and it has very little violet fringing. Optics are tack sharp...but make sure you don't drop it on your foot!! 

 

Cheers, Chris.

[Echolight]

I would investigate the SVBony SV225.

 

It looks like the arm can be tilted 45 degrees in either direction, so you could mount the C6 on the left side. But I can't say for sure.

It also appears to be much stronger than a Twilight I.

[aa6ww]

A C6 with a .63 focal reducer will get you down to 945mm FL. With a 24mm Panoptic or ES24mm 68 deg 1.25" eyepiece will give you 1.75 degs field of view.

That's plenty wide for most deep sky objects realistically.

Be aware that the C6 Celestron in its current black OTA configuration seem to exhibit the diamond ring effect when looking at bright objects. The rim of the light baffle is the culprit and should be either flocked or repainted with a thick coat of flat black paint. 

 

The Meade 6" f/10 LX85 ACF Optical Tube Assembly, though not cheap, is what the C6 Optically wishes it was. Its an Edge HD in a 6" SCT. The views are impressive vs a C6 in how flat and sharp stars are out to the edge FOV.

 

https://www.meade.co...-assembly-2.pdp

 

Your mount can handle it.  Good luck on which ever direction you take.

This is just my 2 cents worth.

 

 

https://www.cloudyni...g-diamond-ring/

 

https://www.cloudyni...le-tube-issues/

 

 

 

 

- Ralph

Edited by aa6ww, 23 February 2024 - 11:04 AM.

[Jon Isaacs]

Hi Jon!

Thank-you for that insight...I will definitely pay more attention next time I have the ST80 on the mount and will experiment with many more eyepieces. I will endeavor to do that sooner than later. That being said...and having done quite a bit of A-focal imaging through both the ST80 and the SW 120x600, the SW 120x600 is far superior...but the larger optics will likely have much to do with that. The ST80 has spent literally a thousand hours on my double star imaging scope as my finder and casual observing scope during the imaging sessions. I am pairing it up with a 32mm Celestron plossl and in my humble opinion, the outer third of the field is mushy. It would be very instructive to be able to add my 22mm Nagler to the ST80 but alas, the ST80 does not have a 2" focuser. The 22mm Nagler combined with the SW 120x600 has provided some of the most spectacular views I have had at an eyepiece...sharp to the limits of the field...you almost feel like you are immersed in the star field.

 

For those checking out the used market, the old, no longer made Stellarvue 80mm Nighthawk, at F6, is a wonderful small scope. The only issue with it, it weighs a ton...likely enough aluminum in the OTA for 2 scopes. It is an achromat and it has very little violet fringing. Optics are tack sharp...but make sure you don't drop it on your foot!! 

 

Cheers, Chris.

 

Chris:

 

I imagine the mushy outer field is due to the combination of the objectives curved focal plane and the eyepiece.  There are lots of things one can do.. 

 

I'm oversubscribed in the world of short focal length refractors and high quality wide field eyepieces.. And ST-80 with a 2 inch focuser, TSFLAT2 and the 31 mm Nagler does a pretty good job of providing a clean 6.0 field of view. And there's some fast apos that get the bulk of the low power work.

 

But you've got the 120 mm F/5 and as long as it's not too physically large for your mount or for transporting it, the ST-80 can remain on the back burner without expensive upgrades.

 

Jon

[tdavis4785]

I use a C5 and an 80mm ED on the AzGTi with no issues. I have a NexStar6SE that I use less frequently. The C6 is too heavy for the AzGTi and the NexStar 6SE setup is much larger and heavier than the C5 and AzGTi for not much more capability.

[c2m2t]

Good Afternoon!

For those of you who may not be familiar with the WO Ezi-Touch mount, I have attached an image of my Messier Marathon observing rig. As noted previously the scopes are a SW 120x600 as the wide-field scope and the Orion 120x900 providing the higher magnification. You might be wondering about the pieces of plywood placed around the base of the mount...something I learned during the first MM at this location...the road leading to a local municipalities dump site...standing around all night on cold pavement in the latter part of March means cold feet no matter how well insulated the boots. The plywood provides an insulating break that greatly reduces the conductive heat loss. 

 

During the nights, this road is effectively a dead end and because of the importance of the access to the dump, the road is kept clear all winter and is kept in great shape. We have had upwards of 15 observers lined up along one lane of the roadway doing a marathon. 

 

Cheers, Chris.

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[aa6ww]

The last C6 I owned, weighed in at 9.6 pounds with an installed 0.63 focal reducer, a 1.25" diagonal and eye piece. It also included a handle. I put it on a UPS Scale. This is less weight the Celestron advertises, which is listed as 10 pounds.

It was completely fine on my AZ-GTi with a small 4 pound counterweight. I eventually sold it for a Orange Tube C5 for my AZ-GTi mount because I was able to get a wider field of view using a focal reducer.

 

-  Ralph

[Bob Campbell]

The last C6 I owned, weighed in at 9.6 pounds with an installed 0.63 focal reducer, a 1.25" diagonal and eye piece. It also included a handle. I put it on a UPS Scale. This is less weight the Celestron advertises, which is listed as 10 pounds.

It was completely fine on my AZ-GTi with a small 4 pound counterweight. I eventually sold it for a Orange Tube C5 for my AZ-GTi mount because I was able to get a wider field of view using a focal reducer.

 

-  Ralph

Surprisingly, my C6 with 0.63 reducer, asi294mc camera,  spacers and telrad also weighs in at 9.6lbs, which was a relief, since I too have a az-gti(eq)

 

Bob

Edited by Bob Campbell, 23 February 2024 - 04:35 PM.

[Exnihilo]

 

As an engineer, simplicity is a virtue. 

 

A fluid head is designed to be used with cameras at angles near the horizon. The camera is mounted above the axis of rotation of the altitude axis. This means the camera becomes more and more unbalanced as the elevation angle is increased.  To attempt to deal with this imbalance, viscosity, springs and sometimes counterweights are needed. 

 

When a telescope is mounted on a fluid head,  this becomes a larger issue because a telescope mount needs to optimized for viewing at high elevation angles.. 

 

The complexity of this solution can be avoided simply by mounting the telescope so the rotational axis of the altitude axes passes through (or near) the center of gravity of the telescope. The telescope balances itself so counterweights, springs and viscosity are unnecessary. 

 

This is the basic principle of the fork mount, it's a self balancing design. Fork mounts can support the scope from one side or from both sides. With larger scopes, both sides are generally used for added support, LX-200 mounts for example. The Dobsonian mount is a fork mount that supports the scope from both sides.

 

For smaller scopes, mounts that support the scope from one side are more that adequate and make mounting using a Vixen Dovetail simple and easy.  Mounts like the Vixen Portamount, the Explore Scientific Twilight 1 and Twilight 2, StellarVue mounts, Discmounts and many others are single sided fork mounts that provided so!I'd, smooth, tracking over a wide range of magnifications.

 

Some added slow motion controls to provide precise slewing, centering and tracking at high magnifications.  I prefer slow motion controls.

 

I've never owned a C-6 but I've owned three C-5s, two were mounted on a Vixen Portamount, one was mounted sidesaddle on a Bogen 3047, a balanced design. 

 

For a C-6, I'd use a Portamount or my Astro-Tech Voyager from 15 years ago. I have a Bogen fluid head.. 

 

Jon

Hmmm, I have C6 and a Porta II, but I've never tried the C6 on the Porta; I normally put the C6 on a Super Polaris due to the fact I pretty much only use equatorials.  For me, a C6 on a Super Polaris is a "grab and go"; I can usually polar align within about 3 minutes.  But I'll try the C6 sometime on the Porta, sounds interesting!

Edited by Exnihilo, 23 February 2024 - 04:44 PM.

[ABQJeff]

Food for thought...150mm Mak paired with 80mm F/6 triplet apo on an AzGtiX.  Low mag/wide field and high mag/deep field all in one set-up with only one alignment necessary. 

 

An ST80 and C6 would be very a similar (but less expensive and less weighty) combo.

Edited by ABQJeff, 23 February 2024 - 05:04 PM.

[MarkMittlesteadt]

I prefer a C5 to the C6. I've had both. The C5 can do high power or wide field (with a 6.3 reducer) and fit easily on almost any size mount.

 

[Bob Campbell]

I prefer a C5 to the C6. I've had both. The C5 can do high power or wide field (with a 6.3 reducer) and fit easily on almost any size mount.

 

yes, If I didn't want the option of hyperstar with my C6 in the future, I would replace it with  a C5.

 

Bob

[sevenofnine]

The fence is very hard to sit on  If you decide that an 80mm refractor is right for you then consider the AT80ED over the ST80. The CA is mostly gone and it's sharper. The build quality is much better too. Good luck with your decision! 

 

https://www.astronom...ractor-ota.html.