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Have $1200......What to buy

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#1 holeinone73

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Posted 13 March 2018 - 07:54 AM

Please help me on this and I know everyone has their own opinion. I already have a 10" Newtonian so I am focused on Planets and Lunar visual.

 

Celestron 9.25 XLT

 

Skywatcher 180 Mak

 

Orion 180 Mak

 

Every scope is going on a Celestron CG5 Mount. I'm young and strong so I am not worrying about weight or any of that stuff. Just need the best visual experience for my son.

 

Thank you



#2 Exnihilo

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Posted 13 March 2018 - 08:01 AM

 What kind of CG5?   If it’s the older generation with the aluminum extruded legs (I.e. not tubular steel), that 9.25 will have issues.  The Maks are virtually identical, both made by Synta, and just branded differently.



#3 holeinone73

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Posted 13 March 2018 - 08:25 AM

 What kind of CG5?   If it’s the older generation with the aluminum extruded legs (I.e. not tubular steel), that 9.25 will have issues.  The Maks are virtually identical, both made by Synta, and just branded differently.

 

Its the newer sturdy CG5......the one rated 35lbs+



#4 HarryRik9

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Posted 13 March 2018 - 08:33 AM

https://stargazerslo...lestron-c8-sct/

https://www.cloudyni...-c-11-xlt-r1419


Edited by HarryRik9, 13 March 2018 - 08:37 AM.


#5 Eddgie

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Posted 13 March 2018 - 08:47 AM

Please help me on this and I know everyone has their own opinion. I already have a 10" Newtonian so I am focused on Planets and Lunar visual.

 

Celestron 9.25 XLT

 

Skywatcher 180 Mak

 

Orion 180 Mak

 

Every scope is going on a Celestron CG5 Mount. I'm young and strong so I am not worrying about weight or any of that stuff. Just need the best visual experience for my son.

 

Thank you

Your question is not really that clear to me.  Are you asking which of these you should buy if you want to get better planetary performance?

 

If so, my answer would be to take $800 of the budget and have a professional mirror shop check and re-figure your primary, as required, to bring it to a .95 or better Strehl.

 

Take the money saved and use that to buy an inexpensive BInoviewer.

 

You won't do better on plantes with any of these other scopes and conventional eyepeices.  You have the right scope type, so spend your money making the mirror as high quality as possible and get the binoviewer to improve your visual resolution.

 

You can always reverse the order and start with the binoviewer.

 

C 9.25 was not (for me anyway) a very competent planetary scope.  A 10" Newt with a high quality primary will challange a top end 7" Apo on planets.

 

In other words, you would be taking a big step backwards unless your current mirror is very poor, and I have giving you the prescription to remedy that.

 

Have fun!


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#6 ChristianG

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Posted 13 March 2018 - 09:23 AM

Please help me on this and I know everyone has their own opinion. I already have a 10" Newtonian so I am focused on Planets and Lunar visual.

 

Celestron 9.25 XLT

 

Skywatcher 180 Mak

 

Orion 180 Mak

 

Every scope is going on a Celestron CG5 Mount. I'm young and strong so I am not worrying about weight or any of that stuff. Just need the best visual experience for my son.

 

Thank you

The two 180 Maks are identical. Great scope, narrow field of view. The 9.5"'SCT is much bigger. On planets, seeing is the limiting factor usually and the larger aperture of the SCT may not actually give a better image than the 7"'Mak. Light collection is not relevant.

 

If I were you, I'd go for the Mak. Well, I did just that in fact. IMHO (and IMH experience) a good C8 is inferior to a good 7" Mak on planets. A C9 might be on par. A C11 or C14 however will definitely be better. But harder to mount. And will need to be collimated from time to time. A 180 Mak is fine on a CG5 and holds its collimation for years, even decades (Questar).

 

Now if the clouds would go away...

 

--Christian



#7 BillP

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Posted 13 March 2018 - 09:25 AM

Depends on what you are after.  The C925 has a good amount more light gathering.  Visually in my testing it went as deep as my 10" Dob.  Off-axis has coma and FC though since not an Edge variety, so wide fields at low power will show this.  Its baffle tube in the C9.25 is large so no issue with 2" max TFOV eyepieces.

 

On the Maks, they are f/15 instead of f/11-12 which means they will probably show coma as well.  Less light gathering, but smaller footprint.  Not sure what their baffle tube diameter is or what the threading is on the back so do not know how many common accessories can be used.

 

You have C9.25 SCT and two 7" Maks in the list, any reason you do not have a corrected 8" SCT as a contender also?  A Meade ACF or Celestron C8 Edge OTA also are at that price point and you will get a corrected field of view with a good off-axis.  I personally would go with the ACF design since it is more forgiving with collimation than the tight tolerances the Edge design have with the secondary.  Also like that the baffle tube is not obstructed to can get a CAT cooler in there for rapid acclimation.  And if you want certified good optics, then purchase from Company 7.


Edited by BillP, 13 March 2018 - 09:26 AM.


#8 BillP

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Posted 13 March 2018 - 09:40 AM

IMHO (and IMH experience) a good C8 is inferior to a good 7" Mak on planets. A C9 might be on par.

 

Can you elaborate on this some please?  If it is solely from experience then how did you verify both samples were to the same spec?  If both samples were diffraction limited, and both have >30% COs, then I can't see how two essentially similar folded optic systems would be different enough that the smaller aperture would overcome the larger aperture.  Their baffling and light suppression and resulting MTF should not be much of any difference.  So if all the optics are at the same level of precision and the tube engineering is similar, just not seeing how the larger one would not do better.  And on the C9.25, I tested that against my 10" Dob and they were very much on-par, so would expect a small 7" instrument to lag quite a bit behind.  So unless I am missing something, I am suspecting you might have had a fairly poor C8 sample.


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#9 gfstallin

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Posted 13 March 2018 - 10:21 AM

I have to agree with Eddgie here (though I love my C9.25 on planets). Your Newtonian, provided the mirror is of good quality, likely can already best any of those telescopes you listed on nights when seeing favors more aperture. Those are quality telescopes you listed, but they aren't really going to best a quality, 10" Newtonian if you are strictly concerned about planetary views.

 

However, if you are concerned about portability, ease of set up and tracking, then we are talking about something a little different here, particularly if your Newtonian is a manually-tracked Dobsonian. Factors other than optics can come into play to impact planetary views, such as not wanting to move the telescope every 3 seconds or not wanting to haul around a 45-lbs+ equatorial head for that Newtonian. Those other telescopes can begin to make much more sense in terms of reasons to purchase them. 

 

George



#10 tmaestro

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Posted 13 March 2018 - 11:00 AM

The OP might be in a similar situation to where I was a couple years ago.  

 

The Dob puts up great planetary views, but 250x on Jupiter goes by quickly in the eyepiece.  You have to set it up at the field edge, get off the eyepiece, get your son up on the stool and watch as he tries futilely to get his eye right on the eyepiece and then he rests his hand on the Dob to steady himself and you have to ask him to get off again and then swirl around and find Jupiter again and start over.

 

Tracking is a godsend when you're trying to share your telescope.


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#11 Eddgie

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Posted 13 March 2018 - 11:19 AM

If tracking is a major issue,  he should sell the CG5 (or not buy it if he does not have it already) and sell his current 10", and replace it with a 10" Go2 Newt or buy a tracking platform.

 

None of these scopes are going to improve his view over the scope he already has.   

 

The OP is undoubtedly being influenced by the "C 9.25s are Special" and "MCTs are Magic" Kool-aide.  Anyone that has used all of these scopes on planets and compared them to a Zambuto 10" reflector will tell you that there is no comparison whatsoever.  

 

And the only difference between his scope and the Zambuto scope is the quality of the mirror, and he can fix that for $800.

 

I think the OP is wasting money to buy these other telescopes if planetary is his passion.   


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#12 holeinone73

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Posted 13 March 2018 - 11:50 AM

  • The 10" Newtonian is the Orion version F 4.7. I really appreciate the input, the CG5 Mount I have is the advanced GT version so I do have tracking and the sturdiness to support these platforms. I am turnkey when I comes to telescopes, if I go to replace a mirror odds are in my favor to break something.
  • The Skywatcher Mak 180 has a 2" Rear Cell adapter and the Orion only has a 1.25" I know the FOV varies on each one but how much I don't know the specifics.
  • Thanks for the input on the Edge and ACF I will investigate further.

Thanks for all the input on these scopes.



#13 tmaestro

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Posted 13 March 2018 - 11:52 AM

If tracking is a major issue,  he should sell the CG5 (or not buy it if he does not have it already) and sell his current 10", and replace it with a 10" Go2 Newt or buy a tracking platform.

 

None of these scopes are going to improve his view over the scope he already has. 

 

The OP is undoubtedly being influenced by the "C 9.25s are Special" and "MCTs are Magic" Kool-aide.  Anyone that has used all of these scopes on planets and compared them to a Zambuto 10" reflector will tell you that there is no comparison whatsoever.  

 

And the only difference between his scope and the Zambuto scope is the quality of the mirror, and he can fix that for $800.

 

I think the OP is wasting money to buy these other telescopes if planetary is his passion.   

 

Heck yeah, on sale now too!
https://agenaastro.c...ope-s11810.html



#14 carver2011

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Posted 13 March 2018 - 12:32 PM

Where are you located? Are you in a light polluted area? This is a big factor in what would be best for you.
Ed

#15 dr.who

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Posted 13 March 2018 - 12:59 PM

As an alternative go with a Celestron 8" EdgeHD with TEMPest fans from Deep Space Products. It puts up near refractor views once it is properly cooled and with good collimation. If you can swing it add another few hundred and pick up either the new  AT60ED or new AT72EDII refractor and mount it on top of the EdgeHD. The refractor will act as a wide field scope, a potential DSO Astro Photography scope if you go that route, and a finder for the EdgeHD. It is a really great combination because you get the wide field in the refractor and the planetary and smaller DSO with the SCT. You will likely leave the Dob behind once you go that route.  If you purchase from our sponsor, Astronomics, and mention you are a CN member you also get a discount. That makes the purchase a bit easier on the wallet. 
 
And for the record I am not flogging those scopes because Astronomics is a sponsor. I am doing so because they are both great scopes for a very good price point. I have it on my scope purchase roadmap when I have the available funds myself. Here are links to the two scopes.
 
AT60ED
AT72EDII
 
Here is a link in the Refractors forum discussing the AT60ED:

AT60ED thread

If that isn't an option for you then the Skywatcher Mak is a good option.
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#16 holeinone73

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Posted 13 March 2018 - 01:32 PM

Where are you located? Are you in a light polluted area? This is a big factor in what would be best for you.
Ed

Ed I am located in Dayton, OH.....I am 30 minute drive from some decent dark skies. My Southeast view is fairly dark so morning planet viewing right now is fantastic.



#17 shotgun

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Posted 13 March 2018 - 03:09 PM

Plus 1 on what Dr. Who recommends, love my 8"Edge and the sharp views it puts up. Great grab and go scope.  Shotgun


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#18 Patrick

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Posted 13 March 2018 - 03:43 PM

If tracking is a major issue,  he should sell the CG5 (or not buy it if he does not have it already) and sell his current 10", and replace it with a 10" Go2 Newt or buy a tracking platform.

 

None of these scopes are going to improve his view over the scope he already has. 

 

The OP is undoubtedly being influenced by the "C 9.25s are Special" and "MCTs are Magic" Kool-aide.  Anyone that has used all of these scopes on planets and compared them to a Zambuto 10" reflector will tell you that there is no comparison whatsoever.  

 

And the only difference between his scope and the Zambuto scope is the quality of the mirror, and he can fix that for $800.

 

I think the OP is wasting money to buy these other telescopes if planetary is his passion.   

Granted that a Newt can put up some beautiful images, but not everyone is interested in a Dob.  And tracking platforms are a PITA to use...I know, I've had two of them.  They can introduce a lot of scope sway which detracts from seeing those beautiful Newt images.  And then they have to be reset every hour or so.

 

Of the three choices listed by the OP, I would have to go with the C9.25 just because of the aperture differences.  The field of view will also be a bit wider.  The CG5 is capable of carrying the C9.25 for visual as long as you don't bump it much. (same with the other two scopes mentioned.

 

Now, if I were buying the scope for myself, and putting it on the CG-5, I would go with a 8" Edge.  The mount will carry the Edge 8 very well and the optics on the Edge scopes tend to be very good.  

 

Patrick


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#19 Richard Whalen

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Posted 13 March 2018 - 04:39 PM

If tracking is a major issue,  he should sell the CG5 (or not buy it if he does not have it already) and sell his current 10", and replace it with a 10" Go2 Newt or buy a tracking platform.

 

None of these scopes are going to improve his view over the scope he already has. 

 

The OP is undoubtedly being influenced by the "C 9.25s are Special" and "MCTs are Magic" Kool-aide.  Anyone that has used all of these scopes on planets and compared them to a Zambuto 10" reflector will tell you that there is no comparison whatsoever.  

 

And the only difference between his scope and the Zambuto scope is the quality of the mirror, and he can fix that for $800.

 

I think the OP is wasting money to buy these other telescopes if planetary is his passion.   

I have compared my 8" MCT to a 12.5" f5 Starmaster with a CZ mirror on many occasions.  Your right, no contest, my MCT is better every time when planets or the moon are involved. I would go for the MCT, f15. Much better on eyepieces, much more fl, etc


Edited by Richard Whalen, 13 March 2018 - 04:53 PM.


#20 spongebob@55

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Posted 13 March 2018 - 04:41 PM

If you consider any Orion product, you can try it for 30 days, and if you're not pleased with it for any reason, you can return it for a full refund for $9.95 shipping label supplied by Orion's website, no matter what the weight.  

I've had a 180 Orion Mak.  It was superb.  Now I just bought the 150 Orion Mak and its great too.  Plus a 32mm rear cell opening vs 25mm.  Will be trying a f/6.3 fc/fr on it for f/8.  Nice easy set up on my Evolution mount + CPC mount.  

Good luck

SB



#21 Peter Besenbruch

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Posted 13 March 2018 - 04:51 PM

If the OP doesn't want to check the optics on the 10" Newtonian, I would recommend a Maksutov over an SCT for planetary views. I was reading an interesting article by Rohr about testing for "Mikrorauheit" (micro-roughness, lit. micro-rawness). It doesn't show up often on tests used to determine Strehl. You can see it, however, on the Lyot test. Rohr writes:

 

Die von mir gemeinte typische Mikrorauhheit, wie man sie im Lyot-Test erkennen kann. Nicht der Hauptspiegel ist die Ursache, sondern die Glasplatte, aus der die Schmidtplatte hergestellt wurde und die Fangspiegel-retouche sind die Übeltäter. Allgemeine Erörterungen zum Thema Rauhheit helfen leider bei diesem Teleskop-Typ nicht weiter. Es muß ja einen Grund haben, warum die ähnlich aufgebauten Maksutovs sehr viel kontrastreicher
abbilden.

 

"The micro-roughness (lit. micro-rawness) that I mean, you can recognize in the Lyot test. The primary mirror isn't the source, rather the glass plate that the Schmidt plate is manufactured from, along with secondary mirror retouching; these are the "evil doers." General discussions on the topic of "rawness" unfortunately don't help any further with this telescope type (SCT). There must be a reason why similarly constructed (or quality) Maksutovs come across so much higher in contrast."

 

Rohr quotes the following person with approval:

 

Die physikalischen Zusammenhänge zwischen Wellenfrontfehler, Strehlwert und Einfluss auf die Kontrastübertragung (MTF) sind u. a. Schroader, "Astronomical Optics" beschrieben, in geraffter Form auch bei Suiter, "Star Testing Astronomiocal Telescopes". Bei Vernachlässigung der Miktrorauheit ist der Strehlwert prinzipiell falsch ermittelt worden. Das passiert bei der Messung mit einfachen I- Metern immer, bei teuren Industriegeräten zum Teil auch.

 

"The physical coherence between wave front error, Strehl value, and the influence of contrast transfer (MTF) are described in (among others) Schroader, "Astronomical Optics," and in a shortened form also with Suiter, "Star Testing Astronomical Telescopes." By neglecting micro-roughness, the Strehl value is falsely transmitted as a matter of principle. That happens always when measuring with simple I-meters, and partially with expensive, industrial equipment, too."

 

Rohr agrees with this, and says roughness is a part of the SCT manufacturing design, and therefore a pronounced issue with SCTs.

 

So, yes, I recommend a Maksutov, if the OP wants a more "turnkey" solution. That said, I recommend insulating the Maksutov to make it more grab and go friendly (good advice for SCTs, too). When it comes to Orion vs. Skywatcher. Synta makes both. Skywatcher in the United States has better service after the sale if something goes wrong.


Edited by Peter Besenbruch, 13 March 2018 - 04:53 PM.


#22 AxelB

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Posted 13 March 2018 - 04:55 PM

Please help me on this and I know everyone has their own opinion. I already have a 10" Newtonian so I am focused on Planets and Lunar visual.

Celestron 9.25 XLT

Skywatcher 180 Mak

Orion 180 Mak

Every scope is going on a Celestron CG5 Mount. I'm young and strong so I am not worrying about weight or any of that stuff. Just need the best visual experience for my son.

Thank you


What is your 10" newton? You may already have the best scope for the stated purpose... Try posting that in the reflector forum :-)
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#23 Peter Besenbruch

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Posted 13 March 2018 - 05:09 PM

What is your 10" newton? You may already have the best scope for the stated purpose... Try posting that in the reflector forum :-)

There the recommendation would be for the compact and inexpensive TEC APO250VT. Anything less would be disappointing. If you absolutely, positively HAD to cheapen out, then the TEC APO180FL might be a barely acceptable substitute.

 

At this point, the Russian contingent would weigh in and insist that the LZOS 254/2250 refractor is the only way to go.



#24 Patrick

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Posted 13 March 2018 - 11:15 PM

Damion Peach gives a pretty good review of the Celestron Edge 8 HERE.  Interesting how well such an awful instrument works in the hands of a master. smile.gif

 

Patrick



#25 Richard Whalen

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Posted 14 March 2018 - 12:07 AM

The C8 edge, while a nice scope is not optimized for planetary observing which he seems interested in. Will it work? Sure, but there are better choices out there. Plus optical quality seems hit or miss, some very good ones, and some not so much from IF reports I have seen from various testers. Very good general purpose scope though if you get a good one. If you go with any SCT, buy it from a company with a great return policy like Company 7.

 

A 180mm f15 MCT that is well made is a better planetary scope, usually better contrast and smoother optics plus smaller obstruction. Plus the additional focal length is nice as you can use longer fl eyepieces to get the same magnification which equals more comfort. Good luck with whatever you choose.




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