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Which Telescope should I buy?

astrophotography cassegrain catadioptric Maksutov observing Orion planet reflector moon
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#1 HotRod217

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Posted 22 January 2021 - 02:56 PM

Hello everyone, 

 

I would like to buy a new telescope. I already had a small and cheap refractor and would like to get a much bigger and better scope. It should work for both visual observing and maybe Astrophotography. Here are my two options:

 

1.    180 mm Maksutov-Cassegrain (2700 mm focal length, f15) from Orion

2.    8" Newton-Astrograph (1000mm focal length, f3.9) from Orion

 

Both would be mounted on the Orion Sirius Mount. 

 

My main questions are:

 

1.   Which one is more fun for visual observing?

2.   How bright are deep sky objects on the Maksutov?

3.   Can you use the Newton-Astrograph for terrestrial viewing?

4.   Is there a huge difference between them when observing the moon and planets?

5.   Which one would you get?

 

 

Thanks in advance, 

 

Simon



#2 aeajr

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Posted 22 January 2021 - 03:13 PM

Visual and AP have very different requirements. Visual is all about aperture. Tracking can be manual or motorized. The bigger the aperture the better.

 

AP is all about the mount and excellent tracking. AP guys often use small refractors for imaging. You want that mount to be rock steady.

 

So, is this primarily for visual or imaging


Edited by aeajr, 22 January 2021 - 03:18 PM.

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#3 HotRod217

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Posted 22 January 2021 - 03:20 PM

Visual and AP have very different requirements. Visual is all about aperture. Tracking can be manual or motorized. The bigger the aperture the better.

 

AP is all about the mount and excellent tracking. AP guys often use small refractors for imaging. You want that mount to be rock steady.

 

So, is this primarily for visual or imaging

Primarily for visual, imaging maybe in the future with a refractor.


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#4 SeattleScott

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Posted 22 January 2021 - 03:31 PM

The Mak should provide a bit sharper views and be lower maintenance. Both will be about as bright. The reflector will be capable of going much wider. The Mak would be good for planetary imaging. The reflector would be good for DSO imaging. Neither is particularly great as a first serious visual scope.

It isn’t really realistic to use either for terrestrial viewing, for different reasons.

Scott

Edited by SeattleScott, 22 January 2021 - 03:32 PM.

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#5 Barlowbill

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Posted 22 January 2021 - 03:39 PM

The Newtonian will show upside down views.  Not really cool for terrestrial viewing unless you are a contortionist.  



#6 rhetfield

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Posted 22 January 2021 - 03:50 PM

For general purpose visual, I would look at an 8" F6 dob with a 2" finder.  The astrograph would be hard to focus and collimate due to the low f-ratio.  The F6 would have a wider field of view than the mak and would still do good at high magnification.  The dob base can be bought with goto or pushto or you can save money by making degree circles for it.   


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#7 rhetfield

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Posted 22 January 2021 - 03:51 PM

The Newtonian will show upside down views.  Not really cool for terrestrial viewing unless you are a contortionist.  

You just have to be able to adapt to things being upside down.  Doesn't really bother me all that much, though I could see why it would freak others.



#8 Jeffmar

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Posted 22 January 2021 - 04:09 PM

The 180mm Maksutov is probably going to be overkill for terrestrial viewing and the Newtonian gives upside down views, like everyone said. I have an 80mm spotter scope I use for looking at landscapes and rarely use more than 20x, which is a lot for looking at objects on the ground. If you want a scope that can work for all the things you mentioned you might want a refractor with an extra 45 degree diagonal just for terrestrial viewing. Apochromatic refractors can be pretty expensive, but you can push the magnification a lot more than with achromatic refractors. The views are sharper, and you don’t get purple halos around bright objects. You can see quite a few things in the sky with an eyepiece, and do great astrophotography with one of these scopes. The down side is you won’t be getting the detail while looking at dim objects like you would with a bigger Newtonian scope.



#9 spaceoddity

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Posted 22 January 2021 - 05:03 PM

The astro-graph is more specialized for photography. I think his one would be better for visual while still able to do some A-P. https://optcorp.com/...xkaAlHnEALw_wcB

 

I'm no expert on astro-photography but most recommend a small, high quality, short focal length refractor(APO triplet or ED doublet) that is less than half the weight of the mounts capacity for starting in AP. 



#10 sevenofnine

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Posted 22 January 2021 - 11:48 PM

I will give you the standard recommendation...an 8 inch Dobsonian. It is the cheapest way to get excellent views of a wide variety of night sky objects. It's also the easiest to use. To transport it simply put the tube in the backseat and the base in the trunk of your car. The base of the Dob is a simple rocker box made of particle board laminate. So you are mostly paying for the optical tube. All other scopes cost more because you should spend roughly equal amounts on the tripod and mount as you do on the optical tube. Good luck on you choice!


Edited by sevenofnine, 23 January 2021 - 11:53 AM.

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#11 aeajr

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Posted 23 January 2021 - 10:35 AM

Primarily for visual, imaging maybe in the future with a refractor.

Why did you pick the scopes you listed in the first post?  They are not scopes I would typically recommend as first scopes, so, why these?

 

Based on these, your budget seems to be fairly healthy.   Don't forget you will need to add eyepieces and other accessories.

 

You said you would get them on an Orion Sirius Mount which I believe is a GoTo mount.   Is a computerized mount a requirement?

 

 

OK, next questions:

 

  • Where will you store it?
  • Where will you use it?
  • How will you move it?
  • Does it need to fit in your car? What car?

 

Different types of Telescopes
https://telescopicwa...-of-telescopes/

 

If we think of horsepower as the measure of the power of a car, aperture is the measure of the power of a telescope for visual observing. The larger the aperture the more you can see and the brighter the objects will be.

 

The price performance leader in the aperture/$ is the Dobsonian when we get over 4" in aperture.   This is a Newtonian optical tube on a Dobsonian mount.   Extremely popular in the hobby.

 

But there are many other types of scopes and mounts and they each have their advantages.  Which would be best for your might be made clear by your answers to my questions. 

 

A popular first scope is a 6" to 10" Dobsonian type telescope.  These can be on a manual, PushTo or GoTo mount.  Orion, GSO, Apertura, Zhumell, Sky-Watcher are all good brands.  They mainly differ by their accessories, but optically they would be very similar. 

 

SCTs on GoTo mounts are likewise extremely popular in the 5" to 8" range.

 

Nothing wrong with a large Mak on a GoTo mount but the field of view of a 2700 mm FL scope will be fairly narrow for some deep sky objects.  And it would be too high power for most daytime use.   

 

For this reason, many people have one scope with a shorter focal length for low power wide view targets to supplement the long FL scope. If you want to use it for daytime too, a smaller refractor, 100 mm aperture or smaller would be a good fit. 

 

An Astrograph is an AP focused scope and not generally recommended for visual observing. Definately not for daytime use. 

 

 

I look forward to your answers to my questions.   They will help me understand more about what scope would be best to recommend for you.  


Edited by aeajr, 23 January 2021 - 10:47 AM.

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#12 jgraham

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Posted 23 January 2021 - 11:25 AM

For visual no contest; the Mak. Maks give sharp, high contrast views. They are not wide field scopes, but they perform well on all but the largest deepsky objects. To go wide-ish I like to use UWA eyepieces, but my trusty old 2” 26mm QX Plossl is my most used eyepiece.

 

The astrograph is more of a specialized telescope. Good for wide fields, but tough on eyepieces an may need a coma corrector to work well.

 

For AP, no contest; the astrograph. However, Maks, like their Cat cousins, make good general purpose scopes.

 

Enjoy shopping around!



#13 oldtimer

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Posted 23 January 2021 - 11:33 AM

Google 'telescope blacklist'



#14 spaceoddity

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Posted 23 January 2021 - 12:13 PM

I will give you the standard recommendation...an 8 inch Dobsonian. It is the cheapest way to get excellent views of a wide variety of night sky objects. It's also the easiest to use. To transport it simply put the tube in the backseat and the base in the trunk of your car. The base of the Dob is a simple rocker box made of particle board laminate. So you are mostly paying for the optical tube. All other scopes cost more because you should spend roughly equal amounts on the tripod and mount as you do on the optical tube. Good luck on you choice!

Agreed totally. The OP already has an orion sirius mount however. I think a 8" f/5 newt like the orion one I linked above would be a good choice. That mount could probably easily handle a 10" newt weight wise, but that tube would be a bit too unwieldy. An 8" f/5 newt would be fine on an EQ mount and a very good all around performer, only issue would be that the eyepiece could occasionally end up in some uncomfortable locations.    



#15 HotRod217

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Posted 24 January 2021 - 05:16 AM

Why did you pick the scopes you listed in the first post?  They are not scopes I would typically recommend as first scopes, so, why these?

 

Based on these, your budget seems to be fairly healthy.   Don't forget you will need to add eyepieces and other accessories.

 

You said you would get them on an Orion Sirius Mount which I believe is a GoTo mount.   Is a computerized mount a requirement?

 

 

OK, next questions:

 

  • Where will you store it?
  • Where will you use it?
  • How will you move it?
  • Does it need to fit in your car? What car?

 

Different types of Telescopes
https://telescopicwa...-of-telescopes/

 

If we think of horsepower as the measure of the power of a car, aperture is the measure of the power of a telescope for visual observing. The larger the aperture the more you can see and the brighter the objects will be.

 

The price performance leader in the aperture/$ is the Dobsonian when we get over 4" in aperture.   This is a Newtonian optical tube on a Dobsonian mount.   Extremely popular in the hobby.

 

But there are many other types of scopes and mounts and they each have their advantages.  Which would be best for your might be made clear by your answers to my questions. 

 

A popular first scope is a 6" to 10" Dobsonian type telescope.  These can be on a manual, PushTo or GoTo mount.  Orion, GSO, Apertura, Zhumell, Sky-Watcher are all good brands.  They mainly differ by their accessories, but optically they would be very similar. 

 

SCTs on GoTo mounts are likewise extremely popular in the 5" to 8" range.

 

Nothing wrong with a large Mak on a GoTo mount but the field of view of a 2700 mm FL scope will be fairly narrow for some deep sky objects.  And it would be too high power for most daytime use.   

 

For this reason, many people have one scope with a shorter focal length for low power wide view targets to supplement the long FL scope. If you want to use it for daytime too, a smaller refractor, 100 mm aperture or smaller would be a good fit. 

 

An Astrograph is an AP focused scope and not generally recommended for visual observing. Definately not for daytime use. 

 

 

I look forward to your answers to my questions.   They will help me understand more about what scope would be best to recommend for you.  

My budget is around 2000-2500$. I need a Telescope that gives me clear views of the moon and planets and it would be nice if I could see some deep sky objects as well. I would like to buy a GoTo mount with it to do some astrophotography with a 200mm camera lens or small refractor sometime in the future. I live in Germany under a Bortle 4 sky, so I would use it in my backyard. This seemed like a good deal for me: https://www.telescop...160/p/24764.uts


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#16 GoFish

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Posted 24 January 2021 - 06:18 AM

IMO, an 8” f/5 Newtonian is a little too much scope for the Sirius mount. Same would be true for an 8” f/4 astrograph. And using a Newtonian for visual on an equatorial mount is an exercise in frustration due to the uncomfortable eyepiece positions.  

 

Yes, you can fit the tube with inexpensive Wilcox rings. But extreme care would be needed with that tube/mount combo when rotating the tube to avoid messing up the goto alignment (BTDT). 

 

So I think the Mak alternative makes a lot more sense for the Sirius mount. 

 

Is there a reason you are not considering an 8” f/10 SCT?  Probably not quite as sharp as the f/15 Mak on bright objects, but a little more versatile. Can easily be shortened to f/6.3 for wider field views. And would be more EAA-friendly if you ever go that direction. 



#17 aeajr

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Posted 24 January 2021 - 11:50 AM

My budget is around 2000-2500$. I need a Telescope that gives me clear views of the moon and planets and it would be nice if I could see some deep sky objects as well. I would like to buy a GoTo mount with it to do some astrophotography with a 200mm camera lens or small refractor sometime in the future. I live in Germany under a Bortle 4 sky, so I would use it in my backyard. This seemed like a good deal for me: https://www.telescop...160/p/24764.uts

Based on your criteria, I think that would be a good choice, especially if you can store it in a convenient, ground level location so you don't have to make multiple trips up and down stairs.    And if you can store it in a well ventilated garage or shed, you can reduce the thermal adaptation time and may be able to store it, fully assembled and move it on a cart. 

 

Maks take a while for thermal adaptation, at least an hour for a scope that size.  If you can store it outside, at ambient temperature, you can cut this time down as compared to if you store it in the house. 

 

Don't forget to plan to add eyepieces.   Based on the 2700 mm FL of the scope, the included 25 mm Plossl eyepiece will give you  108X and about .48 degree field of view, just about the span of the full Moon.    

 

For planets you will want to be able to go to higher powers.  This can be done with individual single FL eyepieces or with a zoom eyepiece.

 

For a Zoom I would suggest the Baader Hyperion Clickstop 8-24 zoom.  You won't need the Barlow option for this scope.  That eyepiece would give you 112X to 337X and everything in between.   That will get you off on a good start.

https://agenaastro.c...ce-2454826.html

 

The field of view will not be as wide as some single focal length eyepieces, but for planets and the moon, on a tracking GoTo mount, that should not be a problem.   If you wish you can add single FL eyepieces later, once you have a good idea what you want. 

 

The BH Zoom is my main eyepiece in my 12" scope.

 

It says it has a 2" visual back with a 1.25" diagonal.   If I understand the spec, that means you could add a 2" diagonal so you could use 2" low power wide view eyepieces in the future.   Good option for more flexible viewing of deep sky objects, some of which can be quite wide. 

 

When you are ready, check with Orion to see which diagonal they would recommend.  You may even consider doing this right away.   Most people have one or two low power wide view 2" eyepieces with the rest being 1.25"

https://www.telescop...ord=2" diagonal

 

In addition to my own scopes I sometimes use a 14" SCT, F10, that has a 3550 focal length.  Great on the Moon and planets.  Also provides some beautiful views on smaller DSOs. That one has a 2" visual back and 2" diagonal so I can use my 2" eyepieces. 

 

2" eyepieces can be quite expensive but with an F15 focal ratio, this one will be fairly forgiving of lower cost 2" eyepieces.  If you want to grab a fairly inexpensive one to get started, the Orion Q70 38 mm might be a good choice.  I have this for my scope.  In yours it should work quite well at a modest cost in terms of what 2" eyepieces can cost.

 

With this one you would get down to 71X and a little less than 1 degree field of view, about double what you would get with the included 25 mm Plossl eyepiece.  Most, but not all, DSOs will fit in this field of view. 


Edited by aeajr, 24 January 2021 - 12:08 PM.


#18 spaceoddity

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Posted 25 January 2021 - 09:04 PM

IMO, an 8” f/5 Newtonian is a little too much scope for the Sirius mount. Same would be true for an 8” f/4 astrograph. And using a Newtonian for visual on an equatorial mount is an exercise in frustration due to the uncomfortable eyepiece positions.  

 

Yes, you can fit the tube with inexpensive Wilcox rings. But extreme care would be needed with that tube/mount combo when rotating the tube to avoid messing up the goto alignment (BTDT). 

 

So I think the Mak alternative makes a lot more sense for the Sirius mount. 

 

Is there a reason you are not considering an 8” f/10 SCT?  Probably not quite as sharp as the f/15 Mak on bright objects, but a little more versatile. Can easily be shortened to f/6.3 for wider field views. And would be more EAA-friendly if you ever go that direction. 

Definitely for photography but it should be fine for visual. The orion 8" newt weighs 16.5 lbs and the sirius is rated for 30. The 8" orion newt is normally sold with the skyview mount which is a step below the sirius and that supports it fine. Mine is on a CG-5 and is also very stable. I would prefer a dobsonian for an 8" scope though.  



#19 GoFish

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Posted 25 January 2021 - 11:43 PM

I’m sure what I’m going to describe is a solvable problem. But I wasn’t interested in throwing any more time or money at it. 

 

I attempted visual observing with my brand new Orion Sirius, 8” f/5 Newt combo.  First time out I didn’t have rotating rings. As I tried to perform the GoTo alignment, the eyepiece got into some impossible positions. If anyone had seen me hanging off the short ladder I needed when an alignment star near the zenith was selected (by the mount), they would have died laughing. 

 

Doing the GoTo alignment just didn’t work with me constantly bumping the tube trying to simultaneously look through the eyepiece and jog the scope using the corded hand controller. 

 

So I built and installed Wilcox rings. Maybe it was just that my tube wasn’t perfectly round, but it still took a lot of effort to rotate the tube because the factory rings remained very tight even when the adjustment screws were fully loosened. 

 

Again, successfully completing a GoTo alignment eluded me after several tries, even with the Wilcox rings. Rotating the tube caused the pointing to change significantly without adjustments made using the hand control/stepper motors. So the GoTo model couldn’t solve. 

 

Long story short:  I would not expect to be successful setting up GoTo on a regular basis with this particular combo. I’m sure it would work fine using manual pointing if you just want the steppers for tracking. 

 

For EAA, I used EQMOD and platesolving for pointing. This worked well, because there was no need to put my eye up to the focuser in oddball positions. But I found that even a slight breeze was more than the mount could tolerate with such a big “sail.”

 

I wouldn’t go any bigger than a 6” f/5 on the Sirius. Or, bump up to the Atlas for the 8” f/5 tube. 


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