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Looking for suggestions for a new scope

Sky-Watcher Esprit 120ED Equipment Refractors Buying Advice
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What scope should I go for?
Multiple choice poll 33 votes
12% (4 votes)
9% (3 votes)
12% (4 votes)
6% (2 votes)
15% (5 votes)
18% (6 votes)
21% (7 votes)
6% (2 votes)
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Joel Lee avatar
Joel Lee avatar
Hi Everyone,

With holiday shopping season in full swing I have been debating a new scope to complement my current lineup. Here’s my current gear: 
  • Cameras (Both IMX571 Color) with EFWs
    • ATR2600C + G3M 678C on OAG
    • ASI2600MC Duo (ASI220 Guider)

  • Scopes
    • Esprit 120ED 840/640
    • Apertura 75Q 400/300
    • Samyang 135mm F2

I love imaging galaxies and I would like to have a lot more light gathering power (integration time) for galaxy season as well as the ability to go for some planetary imaging with barlows/powermates. I will have a mount and tripod that should support 40+ lbs (UMi 20S) so any of these options should be safe for the mount (most of the options are ~30lbs and can be used with my AM5) but would prefer a lighter option since I haul my scopes in and out in the morning half asleep. I would also like the scope to be well corrected for the entire APS-C field and ideally a little more. Although I use BXT, I feel more at ease when my stars are round throughout the image and I don't need to correct them. Lastly, I would like to not blow a budget of $4000 with a stretch for 5000 if there's a very convincingly good option (SVX130T+ is not an option right now). $3500 is a reference around since my Esprit cost me about that much.


I figured with my sky conditions, B7/8, 1 arcsec at best, scopes of around 800-1000mm with my cameras would yield the best sampling and higher focal lengths would not really yield higher resolution images. As a result, I think it would be best to get a fast scope around that focal length. This leads to a couple of options. Double up on the Esprit with another refractor in that class. Get a Newtonian/Mak-Newt around F4/5. Go slow but closer in Bin2 on a C9.25 EdgeHD + 0.7X/RC10 Truss.

Breaking down these options:

Refractor complement: This is extremely straightforward and doubles imaging acquisition easily. Stuff is simple to use but a tad slower and more expensive. Either a Stellarvue SVX102T (This double duties) or some other 120-130mm scope. The boring but reliable option.

8/10 inch Newtonian/Mak-Newt: These are really fast and for regular Newts come with diffraction spikes (I think these look beautiful). Downside is that finding one with mechanics as good as the refractors seems to be a huge issue. In the US the main options are Quattros, Starlux, or I have to import a 8 inch ONTC/TS Astrograph (10 inch has dramatically higher shipping costs). Quattros seem to require about 1000-2000$ of upgrades + extra time to flock, get correctors, new rings, etc and generally seem like a pain. Not really enthusiastic about this. Starlux seems good but I don’t know enough about it or seen enough about it. It seems like it still needs a focuser upgrade so -1000$ as well. TS ONTCs I see mixed things about and their corrected newtonian astrographs I’ve never seen on a forum but look really good. I asked Joe at Parallax Instruments about if there are any available about a couple of weeks back and he told me that the mirrors are backlogged so I can’t get a Parallax Newtonian at the moment. If only there was a Carbonstar 200/250.

C9.25 EdgeHD + 0.7X/RC10 Truss + Bin2: This option is slower than the other ones and sacrifices field of view for a nicer close up view. However, due to seeing conditions, I could just crop on a 800-1000mm 1arcsec/pixel image and get the same image. It does seem like the C9.25 has an advantage for planetary but good Newts can rival it/do better? These scopes seem to also require external/replaced focusers, additional collimation tools, etc.

If I don’t break the bank on the first scope selected I’ll probably also grab a SQA 85 to complement/replace my 75Q.

I'm open to any additional suggestions! Thanks for reading and I appreciate any advice!
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Dale Penkala avatar
Dale Penkala avatar
Well my suggestion is a good 10” f4-5 newt. Many here on AB know that I’m a newt guy. Right now I’m using my 12” f5 Certified newt. I’ve used 6-12” and bang for your buck its the best light gathering instrument for the money IMHO anyway.
Its to bad you didn’t live closer to me in Michigan, I have an 10” f5 that I’d make you a heck of a deal on.

Anyway thats my suggestion an 8-10” newt and I’d lean towards an f5 btw.

Good Luck!

Dale
Joel Lee avatar
Joel Lee avatar
Dale Penkala:
Well my suggestion is a good 10” f4-5 newt. Many here on AB know that I’m a newt guy. Right now I’m using my 12” f5 Certified newt. I’ve used 6-12” and bang for your buck its the best light gathering instrument for the money IMHO anyway.
Its to bad you didn’t live closer to me in Michigan, I have an 10” f5 that I’d make you a heck of a deal on.

Anyway thats my suggestion an 8-10” newt and I’d lean towards an f5 btw.

Good Luck!

Dale

Thanks for the suggestion Dale! Do you have a recommended Newt brand to get or do you recommend going down the grab-the-base Newt like a Skywatcher/GSO then working from there route? I see you have a GSO 12inch. It’s producing great images for you! Do you recommend accessories/modifications for it?
Dale Penkala avatar
Dale Penkala avatar
Joel Lee:
Dale Penkala:
Well my suggestion is a good 10” f4-5 newt. Many here on AB know that I’m a newt guy. Right now I’m using my 12” f5 Certified newt. I’ve used 6-12” and bang for your buck its the best light gathering instrument for the money IMHO anyway.
Its to bad you didn’t live closer to me in Michigan, I have an 10” f5 that I’d make you a heck of a deal on.

Anyway thats my suggestion an 8-10” newt and I’d lean towards an f5 btw.

Good Luck!

Dale

Thanks for the suggestion Dale! Do you have a recommended Newt brand to get or do you recommend going down the grab-the-base Newt like a Skywatcher/GSO then working from there route? I see you have a GSO 12inch. It’s producing great images for you! Do you recommend accessories/modifications for it?

Thanks Joel,

Well my 12” isn’t just a GSO way more than that but thats a long story. Google DBA Astronomy Products Certified and my name and that will give you an idea what my Certified scope is.

As to my suggestion, I’ve had the 12” f4 version to this scope but ended up selling it to a good friend that has done some impressive work with it but yes they do need a bit of work and in all honesty it depends on how picky you are with your images. I’m not a full frame guy so I don’t worry about that much but my 2600mc pro and my Quattro CC works just fine for me, as I’m still tweaking my new camera in. My new 2600 replace my 071mc pro btw.

I’ve used the Orion brand as well and they perform well. All my scopes I’ve used either stock focusers or Moonlite focusers on my scopes. I try hard not to spend the big money for these new focusers on the market.

I have considered the ONTC line for a larger scope but don’t like the idea of importing it. I do think the Sky Watcher Quattro is a good starting point and you can slowly upgrade things as you see fit.

I have an older 10” f5 Celestron newt that has a thick steel tube that I used to use but my 12” replaced that one and at some point I’ll be selling that. Unfortunately I don’t have a way to ship it.

Anyway best of luck and I’ll answer any questions for you if I can.

Dale
Alex Nicholas avatar
Alex Nicholas avatar
If you currently have scopes at 135mm, 300mm, 640mm and 840mm, buying anything else in that focal length range is a waste of time, unless it provides a significant advantage over your current scope at that focal length, but then it would not be a companion scope, but rather, a replacement.

The way I see it is this. 
I would want something that offers me something significantly different to what I currently have.

Take my setup for example.
I had a 65PHQ. 416mm f/l.
When some funds were available, I wanted to go just a bit wider and a bit faster. I bought the reducer… so now I have 312mm f/l and 416mm f/l.
Later, I was looking for something to give me more reach - so I aimed for scopes around the bigger than the 102mm f/7, and eventually chose and bought the 120mm f/7 Askar, giving me almost exactly double the 65PHQ's focal length at 840mm. 

My next plan is to get closer again, as even the 120 f/7 with IMX294 doesn't get close enough for most galaxies.

So my options are:
Aim for something ~1600mm f/l (8" RC, or 10" RC with reducer) or, get a camera with a sensor roughly half the size of the IMX294, and continue to use the 120 APO.

You could do the same. Much like you say, you could crop an image from your Esprit 120 to match a 10" RC field of view and pixel scale, but there is SO much more to aperture than just a function of focal length. A 10" RC is going to see fine details that your 120mm scope simply can't see… And on the nights of good seeing, the 10" RC will capitolise in ways the 120 simply can't.

What would I do?

Given you have 2x IMX571 sensors, I would buy a second Esprit 120 (providing that you like the scope and its field of view) and utilise both your cameras at once. Getting 2x the data for any given length of time is going to yield far better results…. 

If you normally give an image 10hrs of integration, you can either achieve that result in 5hrs time, or continue to run 10hrs on a target, resulting in 20hrs of data. Sounds positive to me!
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Tony Gondola avatar
Tony Gondola avatar
Simple, go for more aperture. There are two ways to benefit from that. You can go larger and super fast so that the focal length isn't much different from the longest you have now and reap the benefits of shorter exposure times and higher resolution. Or, you can go with a slower large aperture system that gives you more focal length then you have now. Once you get above 1000mm the number of possible images explodes because you can take unusual details from common objects that everyone takes the same image of. Something like the Heart and Soul nebula can keep you busy for a long time. No matter how you deploy it, a larger aperture is the way to go.
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Joel Lee avatar
Joel Lee avatar
Dale Penkala:
Joel Lee:
Dale Penkala:
Well my suggestion is a good 10” f4-5 newt. Many here on AB know that I’m a newt guy. Right now I’m using my 12” f5 Certified newt. I’ve used 6-12” and bang for your buck its the best light gathering instrument for the money IMHO anyway.
Its to bad you didn’t live closer to me in Michigan, I have an 10” f5 that I’d make you a heck of a deal on.

Anyway thats my suggestion an 8-10” newt and I’d lean towards an f5 btw.

Good Luck!

Dale

Thanks for the suggestion Dale! Do you have a recommended Newt brand to get or do you recommend going down the grab-the-base Newt like a Skywatcher/GSO then working from there route? I see you have a GSO 12inch. It’s producing great images for you! Do you recommend accessories/modifications for it?

Thanks Joel,

Well my 12” isn’t just a GSO way more than that but thats a long story. Google DBA Astronomy Products Certified and my name and that will give you an idea what my Certified scope is.

As to my suggestion, I’ve had the 12” f4 version to this scope but ended up selling it to a good friend that has done some impressive work with it but yes they do need a bit of work and in all honesty it depends on how picky you are with your images. I’m not a full frame guy so I don’t worry about that much but my 2600mc pro and my Quattro CC works just fine for me, as I’m still tweaking my new camera in. My new 2600 replace my 071mc pro btw.

I’ve used the Orion brand as well and they perform well. All my scopes I’ve used either stock focusers or Moonlite focusers on my scopes. I try hard not to spend the big money for these new focusers on the market.

I have considered the ONTC line for a larger scope but don’t like the idea of importing it. I do think the Sky Watcher Quattro is a good starting point and you can slowly upgrade things as you see fit.

I have an older 10” f5 Celestron newt that has a thick steel tube that I used to use but my 12” replaced that one and at some point I’ll be selling that. Unfortunately I don’t have a way to ship it.

Anyway best of luck and I’ll answer any questions for you if I can.

Dale

Thanks for the information Dale! I did some searching and I see now that they are a bit of work for quite some improvements. Given your results, it seems like I should grab one of the Quattros just to work on and eventually get some good results on it. It's also a fun learning project over time. I'll likely grab it as a side project to one of the other options here as the Quattros are relatively affordable. I'll let you know if I get it and start working on it.
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Joel Lee avatar
Joel Lee avatar
Alex Nicholas:
If you currently have scopes at 135mm, 300mm, 640mm and 840mm, buying anything else in that focal length range is a waste of time, unless it provides a significant advantage over your current scope at that focal length, but then it would not be a companion scope, but rather, a replacement.

The way I see it is this. 
I would want something that offers me something significantly different to what I currently have.

Take my setup for example.
I had a 65PHQ. 416mm f/l.
When some funds were available, I wanted to go just a bit wider and a bit faster. I bought the reducer... so now I have 312mm f/l and 416mm f/l.
Later, I was looking for something to give me more reach - so I aimed for scopes around the bigger than the 102mm f/7, and eventually chose and bought the 120mm f/7 Askar, giving me almost exactly double the 65PHQ's focal length at 840mm. 

My next plan is to get closer again, as even the 120 f/7 with IMX294 doesn't get close enough for most galaxies.

So my options are:
Aim for something ~1600mm f/l (8" RC, or 10" RC with reducer) or, get a camera with a sensor roughly half the size of the IMX294, and continue to use the 120 APO.

You could do the same. Much like you say, you could crop an image from your Esprit 120 to match a 10" RC field of view and pixel scale, but there is SO much more to aperture than just a function of focal length. A 10" RC is going to see fine details that your 120mm scope simply can't see... And on the nights of good seeing, the 10" RC will capitolise in ways the 120 simply can't.

What would I do?

Given you have 2x IMX571 sensors, I would buy a second Esprit 120 (providing that you like the scope and its field of view) and utilise both your cameras at once. Getting 2x the data for any given length of time is going to yield far better results.... 

If you normally give an image 10hrs of integration, you can either achieve that result in 5hrs time, or continue to run 10hrs on a target, resulting in 20hrs of data. Sounds positive to me!

Thanks for the reasoning! Yeah, I'm worried about those days where the seeing does stabilize and I can start to take advantage of those nights. Especially late spring nights were the air is cool but still. In that case, would a 10inch Newt at 1000mm vs the C9.25/10 RC at 1200-1600 (with reducer) be that big of a difference? They should have the same resolving power but the Newt is at a larger pixel scale. 

Yeah, the second Esprit 120 is the fall back. It's a little boring since more different gear better/cooler but it's guaranteed to work.
Tony Gondola:
Simple, go for more aperture. There are two ways to benefit from that. You can go larger and super fast so that the focal length isn't much different from the longest you have now and reap the benefits of shorter exposure times and higher resolution. Or, you can go with a slower large aperture system that gives you more focal length then you have now. Once you get above 1000mm the number of possible images explodes because you can take unusual details from common objects that everyone takes the same image of. Something like the Heart and Soul nebula can keep you busy for a long time. No matter how you deploy it, a larger aperture is the way to go.

Thanks for the suggestion! I agree that more aperture should be better then. 

I guess this also comes up with the question here. There's aperture for gathering power and resolution power but also image scale/speed. Like the 10 RC and the Newt 10inch should have the same resolving power since they have the same aperture but the image scales are going to be vastly different since the 10 RC has far more focal length. It sounds like you both recommend the longer FL since there are those days where I could potentially get usage out of it for extra details at the expensive of overall speed because of these smaller details? Or it seems like either type can reap the benefits as long as the aperture is larger?

Thanks again for responding!
David Russell avatar
David Russell avatar
Alex Nicholas:
If you currently have scopes at 135mm, 300mm, 640mm and 840mm, buying anything else in that focal length range is a waste of time

I agree.

the 10 inch RC is a great scope for Galaxies. 

I was shooting with an FSQ106 and an SVX102T before moving up to the 10 inch.

I would never go back. it did require a bigger mount but thats often the case.

best wishes and clear skies.
Joel Lee avatar
Joel Lee avatar
David Russell:
Alex Nicholas:
If you currently have scopes at 135mm, 300mm, 640mm and 840mm, buying anything else in that focal length range is a waste of time

I agree.

the 10 inch RC is a great scope for Galaxies. 

I was shooting with an FSQ106 and an SVX102T before moving up to the 10 inch.

I would never go back. it did require a bigger mount but thats often the case.

best wishes and clear skies.

Thanks for the suggestion as well David! The more I’m hearing the more I like the 10 RC. Its main downfall would be planetary but it seems to excel at galaxies which I like far more. Probably a compromise worth taking. 

Do you have a recommended flattener and/or reducer for the 10 RC? These seem annoying for me to find.
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Dave Rust avatar
Dave Rust avatar
I really enjoy my 925. And it would expand your selection with its 2350mm. 

i shoot mine as straight f10…no reducer. 

super easy to colimate in the field on a bright star (perhaps once a year). No spider spikes. No dust incursion. No mirror flop.

And I’ve experienced no issues with focus, both before and after adding an EAF. 

As light buckets go, this one is about as easy to use and maintain as a refractor.
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David Russell avatar
David Russell avatar
Do you have a recommended flattener and/or reducer for the 10 RC? These seem annoying for me to find.

You wont need a Flattener.  RCs have a very flat field right out of the box.

a reducer is generally a good thing, as 2000mm of focal length is wonderful on nights of great seeing and great guiding, but when the seeing and guiding are mediocre,  something more around 1500mm will be better to deal with.

My scope came with an AstroPhysics 0.67 reducer, and some people report these dont work too well. my experience has been otherwise.

the AstroPhysics reducer is not a FIXED reducer, Its a variable one, and you adjust the strength by adjusting the spacing.
I space mine so that its more like and 0.75 reducer and F5.9.   this gives me 1484mm focal length, and its been fine for ASP-C

many people suggested that it would not work, and that I would need to buy another 0.8x reducer, but I have no plans to do that.

Hope thats all helpful. Thanks Dave
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Joel Lee avatar
Joel Lee avatar
Dave Rust:
I really enjoy my 925. And it would expand your selection with its 2350mm. 

i shoot mine as straight f10…no reducer. 

super easy to colimate in the field on a bright star (perhaps once a year). No spider spikes. No dust incursion. No mirror flop.

And I’ve experienced no issues with focus, both before and after adding an EAF. 

As light buckets go, this one is about as easy to use and maintain as a refractor.

Thanks for the info on the EdgeHD! I had originally considered this one the prime candidate as well since it is really flexible and well established. Now it's doing better on the poll. I had mainly heard issues with the build/mirror flop but it sounds like from experience it's not really affecting you as much or it's not that big of a deal in reality. I'm also a little hesitant on F10 since I have so much light pollution I want to gather much more integration time and faster ratios should be conducive to that. However, at the size of a 9.25 compared to the 10 inch Newts/10 RCs I can run two of them...
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Joel Lee avatar
Joel Lee avatar
David Russell:
Do you have a recommended flattener and/or reducer for the 10 RC? These seem annoying for me to find.

You wont need a Flattener.  RCs have a very flat field right out of the box.

a reducer is generally a good thing, as 2000mm of focal length is wonderful on nights of great seeing and great guiding, but when the seeing and guiding are mediocre,  something more around 1500mm will be better to deal with.

My scope came with an AstroPhysics 0.67 reducer, and some people report these dont work too well. my experience has been otherwise.

the AstroPhysics reducer is not a FIXED reducer, Its a variable one, and you adjust the strength by adjusting the spacing.
I space mine so that its more like and 0.75 reducer and F5.9.   this gives me 1484mm focal length, and its been fine for ASP-C

many people suggested that it would not work, and that I would need to buy another 0.8x reducer, but I have no plans to do that.

Hope thats all helpful. Thanks Dave

This is very helpful Dave. Thanks! Yeah reducing to around 1600 also allows bin2 which would match the Esprit image scale and make combining those images easier. It is also good to hear that at native it likely works well which makes that option much easier to utilize.
Keith Mombourquette avatar
Keith Mombourquette avatar
Just to throw something different at you …

I recently bought the Sharpstar SCA260.  It is 1300mm f/l at f5.  So far I am very pleased with it.
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Joel Lee avatar
Joel Lee avatar
Keith Mombourquette:
Just to throw something different at you ...

I recently bought the Sharpstar SCA260.  It is 1300mm f/l at f5.  So far I am very pleased with it.

Thanks for the suggestion Keith! How has the SCA been performing for you? To me it’s red (not that big of a fan of red) and is very similar to the 10 inch F5 or 12 inch F4 newts but it trades planetary abilities for a shorter tube. I see you have an 8 HD which is a little different from the 9.25 but similar enough how does the SCA compare to it Mechanically/Optically?
Keith Mombourquette avatar
Keith Mombourquette avatar
Joel

I was looking for something between my Askar at 749mm and the Edge 8, but would have gone longer if I could find something that could also be reduced.  I have the Celestron reducer for the Edge, but I don't like it.  I decided to keep the Edge 8 for distant stuff and I equipped it with the Esatto 2" focuser.  I love tat combination.  Then, I bought the SCA260 after months of looking at other options.  It took me a couple of days to figure out the collimation, but I have it very close now.

I don't have a lot of images to share at this point because we have nothing but clouds.  This needs more time, but will give you some idea.

As far as it being red, well what can I say.
Joel Lee avatar
Joel Lee avatar
Keith Mombourquette:
Joel

I was looking for something between my Askar at 749mm and the Edge 8, but would have gone longer if I could find something that could also be reduced.  I have the Celestron reducer for the Edge, but I don't like it.  I decided to keep the Edge 8 for distant stuff and I equipped it with the Esatto 2" focuser.  I love tat combination.  Then, I bought the SCA260 after months of looking at other options.  It took me a couple of days to figure out the collimation, but I have it very close now.

I don't have a lot of images to share at this point because we have nothing but clouds.  This needs more time, but will give you some idea.

As far as it being red, well what can I say.

Thanks for the clarification and example image! That one looks good! Lots of captured details that make it through compression! I think it’s most similar to a reduced RC10 then but it already has all the extra work done like flattening/better focuser. I’ll do some more reading as well.
Rafael Amarins avatar
Rafael Amarins avatar
I would chose a good Carbon Fiber 10" F4 Newtonian
If I still had to chose a refractor the Askar 151PHQ or the 140 Triplet as a cheaper option
Joel Lee avatar
Joel Lee avatar
Rafael Amarins:
I would chose a good Carbon Fiber 10" F4 Newtonian
If I still had to chose a refractor the Askar 151PHQ or the 140 Triplet as a cheaper option

Do you know/recommend of any other options aside from ONTCs for those Newtonians? I only know of the ONTCs and for those I’ll have to import them.
Ashraf AbuSara avatar
Ashraf AbuSara avatar
Bigger aperture is definitely the way to go for planetary imaging since we can utilize lucky imaging. But if all you want are galaxy images, it takes some exquisite seeing to get details from that bigger aperture, which most of us don't have access to.

I like what I have been able to do with the Epsilon 160ED and a 1.5x Tak extender. After utilizing tools for deconvolution like BlurX it gets really hard to spot a difference with larger scopes unless they are incredibely well sampled under exquisite skies.. Here are close crops a couple of recent examples I captured: 
NGC 7331:
https://www.astrobin.com/n7uoli/B/




M74:
https://www.astrobin.com/t92v7e/
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