Help please! With first “big” scope purchase

[BS269]

I will soon be buying an EQ6-R pro as my future proof mount, and I currently have a 4” reflector (my first scope!) which I was gifted but hardly had the chance to use. I’ve done that much research and had that little opportunity in 3 months to enjoy my 4” scope that I have been planning on my first telescope purchase. And it is literally driving me insane. I saw someone on here call it analysis paralysis and I couldn’t put it better myself.

What I wanted to achieve with this telescope is visual and lunar/planetary imaging. I have a baader Hyperion zoom mk III which I want to make the most of as I’ve not been able to use it to anyway near it’s full potential. The 3 options I’ve considered are:

1. Celestron 9.25” XLT SCT - considered a good visual scope (though not the best wide field due to long focal length), with ability to do planetary imaging and even deep space AP (when I’m more experienced in that bracket). Seemed to be perfect. However I’ve read quite a bit about how it produces softer images, and bad reviews on even the visual experience due to the mass making of them. Can get second hand about £800-£850 but risking paying a lot of money for a poor quality scope. Especially when new they are £1300.. makes me think they have been lowered down that much for a reason.

2. skywatcher 180mm pro maksutov - excellent for planets/lunar, which got me very excited. Apparently good contrast on planets and sharp stars. Narrow field of view, but when most DSO is just grey fuzzies, I can wait. Supposedly good for small galaxies too (has anyone done Galaxy AP with this scope?). However smallest aperture of the 3 options at 7.1” and I’ve no experience to know how good the planetary views will be at different apertures, which worries me that this isn’t big enough. Due to the thick primary lens I’ve heard cool down takes a long time, but this doesn’t bother me too much as at some point I will be storing them in an unheated shed. Dew is also a problem, I’m happy to buy a dew shield/heater but I don’t know if that would resolve the problem entirely. I think the biggest worry is that I’ve heard the planets aren’t even going to be in very good Positions for the next couple of years?! I am interested in this scope but if this is true then I feel like it is just the wrong time to buy one. Bought new is £805 so second hand maybe £500-550? Cheaper and could buy some extra toys to compliment it.

3. Newtonian ota / dobsonian - someone recommended I get a 8” reflector instead, as it is in the same aperture range, would perform just as well as the others, has the ability for deep space AP in the future, would fit comfortably on my mount and it’s seriously cheaper, meaning I could buy even more toys to compliment it. Sounds like a good idea.. even though as I’ve already caught aperture fever before really even starting, and knowing that my mount could probably handle a 10” for my intended use, I would be more inclined to go for the 10”. I then realised I could get a 10” dob, dismantle it, put the Newtonian on the EQ6-R for tracked use when I like, but also gives me the opportunity to use my EQ mount for AP whilst Doing separate visual use on a different mount! The downsides to this are that at around f5 my baader eyepiece isn’t particularly great.. I have the matching Barlow so hopefully shouldn’t be too much of a problem, I’m in quite a windy area which is going to affect my OTA quite badly, and lastly.... how the bloody hell do you look through a 10” reflector pointing high at the sky when mounted in an EQ mount?! I don’t want to use step ladders.

I hope this long ass post doesn’t fall on deaf ears. To anyone who is willing to read all this and give me their advice/experience with these scopes then I salute you. I really can’t wait to get into this hobby, I’m just worried my inexperience and impatience is going to result in me buying the wrong scope.

cheers! 

[newbie alert]

My take on your questions.. no 1 scope will do it all that's why there are variations,  tastes change from person to person so there's no one scope fits all

1, the 9.25xlt is probrably the best size in the range..smaller secondary to the others, not too big or too small, you started off saying for Luna visual and planetary imaging then in caption 1 you said not too good on widefield , and for use for deepsky later on.. I'd stick to planets and moon with this.. you will need to acclimatise this for 1.5-2  hours beforehand, especially if you store indoors..

2, the 180 mak, longer focal length and smaller secondary than the 9.25, better contrast, in my view probrably has a slight edge over the 9.25 but not by much, again cool down time needs to be considered.. sorry don't know anyone that uses a mak on dso,  it's not it's strengths..

3,

8 inch Newtonian , I'm not familiar with newts but there's a few varieties out there again for slightly different jobs.. let's say it's a f5 200mm with a 1000mm fl, it has less fl than both the above, you images will have star spikes, it's a marmite thing, luv them or hate them.. you will need to collimate most sessions unless it's on a fixed pier,  so look up the proceedure on this... for imaging I'd be inclined to go for the f4 Quattro  if using for deepsky..

BUT, I'd be inclined to strap the 4 inch frac to the mount, and try various things that ticks your box first and then at least you can make a decision.. 100mm on the moon will be sharp and impressive.. fov on the planets won't be that good but as you quite rightly said they're quite low and in the lower thicker atmosphere.. like a try before you buy

[newbie alert]

This will help with target fov

https://astronomy.tools/calculators/field_of_view/

[BS269]

15 minutes ago, newbie alert said:

My take on your questions.. no 1 scope will do it all that's why there are variations,  tastes change from person to person so there's no one scope fits all

1, the 9.25xlt is probrably the best size in the range..smaller secondary to the others, not too big or too small, you started off saying for Luna visual and planetary imaging then in caption 1 you said not too good on widefield , and for use for deepsky later on.. I'd stick to planets and moon with this.. you will need to acclimatise this for 1.5-2  hours beforehand, especially if you store indoors..

2, the 180 mak, longer focal length and smaller secondary than the 9.25, better contrast, in my view probrably has a slight edge over the 9.25 but not by much, again cool down time needs to be considered.. sorry don't know anyone that uses a mak on dso,  it's not it's strengths..

3,

8 inch Newtonian , I'm not familiar with newts but there's a few varieties out there again for slightly different jobs.. let's say it's a f5 200mm with a 1000mm fl, it has less fl than both the above, you images will have star spikes, it's a marmite thing, luv them or hate them.. you will need to collimate most sessions unless it's on a fixed pier,  so look up the proceedure on this... for imaging I'd be inclined to go for the f4 Quattro  if using for deepsky..

BUT, I'd be inclined to strap the 4 inch frac to the mount, and try various things that ticks your box first and then at least you can make a decision.. 100mm on the moon will be sharp and impressive.. fov on the planets won't be that good but as you quite rightly said they're quite low and in the lower thicker atmosphere.. like a try before you buy

Sorry should have made it more clear with the Deep sky imaging with the Celestron SCT - the secondary can be replaced with the hyper star which turns it into an f2.3 and around 500mm focal length I believe, or it could be used for smaller deep sky objects without the hyper star but with a reducer. This however would only be done once I was far more experienced in AP and is currently something I am not interested in. This scope would be mainly used for  visual and lunar/planetary imaging. if you need different scopes for planetary and deep space visual then I would prefer planetary. But I thought a standard Newtonian covered both. 

star spikes shouldn’t be an issue Due to what I said above, plus I also quite like them..

my 4” scope is a reflector not a frac (though I don’t know what one of these is), and yes I do intend to use this scope on my mount, if I can.. it’s a 27 year old TAL 1, I don’t know if scopes require anything in particular to fit into the mount, apart from tube rings. When I go to buy the mount I will check with the retailer if this can be achieved. This is another reason for getting a dob, I can use my current scope on the EQ6-R to practice AP whilst using my dob for visual! 

[BS269]

37 minutes ago, newbie alert said:

This will help with target fov

https://astronomy.tools/calculators/field_of_view/

If I get the Newtonian I could use the money I’d saved on a good powermate. Could probably buy it if I got the mak too but not sure I’d need it on that.

beginning to realise that the Barlow I bought with my baader EP may not be used as much as I expected 😂

[Cosmic Geoff]

I'd go for the Celestron C9.25.  I have read very positive reports of these, and suspect the negative reports could be over-fussy, or refer to older scopes made in years of poor quality control.  By the 66% rule, £800-£850 seems a sensible price for a used one.

You could be adventurous and buy one of the new 8" Classic Cassegrains.

Or get the Mak 180, which by all accounts is an excellent planetary scope for its size.

I would not recommend a Newtonian, unless you really need to shave a few hundred pounds off your budget. The SCT has a much greater depth of focus, so there will be no problem attaching imaging accessories such as atmospheric dispersion corrector, flip mirror or filter housing. Not so the Newtonian where you may have as little as 20mm focus range to play with.  Also the more compact SCT has an eyepiece conveniently placed that does not move around as much as that on the Newt.

At my location, the 'seeing' seems to be the limiting factor for planetary viewing or imaging.

[dweller25]

@BS269

You might want to consider the TS 8” Classical Cassegrain.....

https://www.teleskop-express.de/shop/product_info.php/info/p10753_TS-Optics-8--f-12-Cassegrain-telescope-203-2436-mm-OTA.html

[BS269]

1 hour ago, Cosmic Geoff said:

I'd go for the Celestron C9.25.  I have read very positive reports of these, and suspect the negative reports could be over-fussy, or refer to older scopes made in years of poor quality control.  By the 66% rule, £800-£850 seems a sensible price for a used one.

You could be adventurous and buy one of the new 8" Classic Cassegrains.

Or get the Mak 180, which by all accounts is an excellent planetary scope for its size.

I would not recommend a Newtonian, unless you really need to shave a few hundred pounds off your budget. The SCT has a much greater depth of focus, so there will be no problem attaching imaging accessories such as atmospheric dispersion corrector, flip mirror or filter housing. Not so the Newtonian where you may have as little as 20mm focus range to play with.  Also the more compact SCT has an eyepiece conveniently placed that does not move around as much as that on the Newt.

At my location, the 'seeing' seems to be the limiting factor for planetary viewing or imaging.

How long ago was the years of poor quality control? Just incase I do go for it so I know what years to avoid 😂 I do like the versatility of the SCT, I was just very concerned about getting a bad one.

I haven’t considered a classic Cassegrain, and I know nothing about it. What are the advantages of one of these? 

I am very interested in the mak but worried it’s the wrong time to buy one, given the position of the planets being low. Is there something to help improve viewing with this problem? 

a big newt on a EQ mount I don’t really like the sound of if I’m honest. I always thought one day I’d get a nice sized dob and if I have one of them I don’t see the need for another big newt. I like the idea of a more compact telescope on the mount.

this is too hard of a decision to make. Could really do with winning the lottery right now..

 

[BS269]

43 minutes ago, dweller25 said:

@BS269

You might want to consider the TS 8” Classical Cassegrain.....

https://www.teleskop-express.de/shop/product_info.php/info/p10753_TS-Optics-8--f-12-Cassegrain-telescope-203-2436-mm-OTA.html

This looks good! But I don’t fully understand the difference between that and an SCT, besides slightly longer focal length it’s fully reflective. Will it give better views than the SCT?

[Cosmic Geoff]

1 minute ago, BS269 said:

How long ago was the years of poor quality control? Just incase I do go for it so I know what years to avoid 😂 I do like the versatility of the SCT, I was just very concerned about getting a bad one.

There are one or two articles online about the history of the Celestron C8 (of which the C9.25 is a variant).  IIRC the C8's manufactured in the USA for the Halley's Comet apparition some decades ago were reckoned to have poor quality control.  The recent ones are made in China.   I don't know how long the C9.25 has been in production by comparison.  Recent ones made in China with Starbright XLT coatings are hopefully okay. 

There's a guy on this forum who is refurbishing a C8 several decades old.

[Cosmic Geoff]

2 minutes ago, BS269 said:

This looks good! But I don’t fully understand the difference between that and an SCT, besides slightly longer focal length it’s fully reflective. Will it give better views than the SCT?

I can't explain that in a brief reply - you'll have to read the 'small print'.  Performance is similar to a SCT but (for instance) there is no corrector plate to get dewed up. And the secondary mirror is hyperbolic (which used to be difficult to make but Chinese technology seems now able to do it affordably.)  There are one or two reviews on this forum from guys who have bought one.

[dweller25]

6 minutes ago, BS269 said:

This looks good! But I don’t fully understand the difference between that and an SCT, besides slightly longer focal length it’s fully reflective. Will it give better views than the SCT?

The big advantages of the CC over the SCT is that it has no front corrector so the scope will reach ambient temperature much faster which is vital for best planetary performance AND it will not dew up like an SCT does.

Also the optics are made from quartz which improves thermal stabilty.

[johninderby]

Having owned a couple of C8 SCTs and now the 8” CC I do prefer the CC. As well as the far quicker cooldown and no dewing problems also has a fixed primary and a proper crayford focuser so no mirror flop as well as the Crayfords 1:10 fine focus. Holds collimation far better than an SCT.

I fiited a Baader Steeltrack refractor focuser which has loads of focus travel. 👍🏻

 

Edited July 5, 2020 by johninderby

[Cosmic Geoff]

48 minutes ago, BS269 said:

I am very interested in the mak but worried it’s the wrong time to buy one, given the position of the planets being low. Is there something to help improve viewing with this problem? 

Because it's a specialised scope with a small FOV? There is not much you can do about the planets being low other than observe close to meritian transit, and use an atmospheric dispersion corrector. I'd rate an ADC as an essential accessory this year.

[BS269]

3 hours ago, Cosmic Geoff said:

I can't explain that in a brief reply - you'll have to read the 'small print'.  Performance is similar to a SCT but (for instance) there is no corrector plate to get dewed up. And the secondary mirror is hyperbolic (which used to be difficult to make but Chinese technology seems now able to do it affordably.)  There are one or two reviews on this forum from guys who have bought one.

I’ll have a look for some reviews then, Sounds like a good scope though!

[BS269]

3 hours ago, dweller25 said:

The big advantages of the CC over the SCT is that it has no front corrector so the scope will reach ambient temperature much faster which is vital for best planetary performance AND it will not dew up like an SCT does.

Also the optics are made from quartz which improves thermal stabilty.

Sounds good! I’ll definitely look more into it!

[BS269]

2 hours ago, johninderby said:

Having owned a couple of C8 SCTs and now the 8” CC I do prefer the CC. As well as the far quicker cooldown and no dewing problems also has a fixed primary and a proper crayford focuser so no mirror flop as well as the Crayfords 1:10 fine focus. Holds collimation far better than an SCT.

I fiited a Baader Steeltrack refractor focuser which has loads of focus travel. 👍🏻

 

Looks like a great scope! Do you know which UK sites you can buy one from? Also can you still use a reducer in this type of scope? What kind of accessories would you say are necessary for either visual or imaging?

sorry for all the questions, this seems like a great option and just want to know more about it before making my decision. 
 

cheers!

[BS269]

2 hours ago, Cosmic Geoff said:

Because it's a specialised scope with a small FOV? There is not much you can do about the planets being low other than observe close to meritian transit, and use an atmospheric dispersion corrector. I'd rate an ADC as an essential accessory this year.

Well I don’t know how much them being low down obscures the view. I don’t really want to get a mak and then the planets not even be worth looking at due to their position. I’ve just heard about an ADC though so maybe it’s still possible to get good views? 

[johninderby]

Can’t buy it in the UK but Telescope Express is a great dealer and delivers to the UK in about two days.

https://www.teleskop-express.de/shop/product_info.php/info/p10753_TS-Optics-8--f-12-Cassegrain-telescope-203-2436-mm-OTA.html

Not much needed in the way of accessories except of course for a diagonal and a finderscope. Don’t know of anyone using a reducer although an SCT type should work.

As it uses a crayford focuser that is an advantage for imaging and the fixed primary also helps and has a large illuminated image field of 45mm.

 

Edited July 5, 2020 by johninderby

[Cosmic Geoff]

37 minutes ago, BS269 said:

Well I don’t know how much them being low down obscures the view. I don’t really want to get a mak and then the planets not even be worth looking at due to their position. I’ve just heard about an ADC though so maybe it’s still possible to get good views?

The lower the object, the more atmosphere the light has to travel through, and the shimmering caused by the atmosphere is correspondingly worse.  Have you noticed how stars near the horizon twinkle more than stars near the zenith? And the lower the object, the more the atmosphere disperses the light into colours, acting like a prism.  This last can be fixed (reversed) using an ADC but the shimmering (=bad seeing) can't be fixed in an amateur situation.   In past years I have obtained useful images with planets at altitudes of 12 degrees or less.

Planets near the horizon can also be blocked by buildings and trees. That's another issue altogether, but one you should check before investing £££'s.  You can check the altitude of the planets at any given time using websites like this one: https://heavens-above.com/PlanetSummary.aspx?lat=52.0406&lng=-0.7594&loc=Milton+Keynes&alt=110&tz=GMT

and use a planetarium program in conjunction with what you can see in the southern night sky to estimate the height of any obstacles.

Or get up at 1 to 2 am this coming morning and take a look. 🙂

[BS269]

54 minutes ago, johninderby said:

Can’t buy it in the UK but Telescope Express is a great dealer and delivers to the UK in about two days.

https://www.teleskop-express.de/shop/product_info.php/info/p10753_TS-Optics-8--f-12-Cassegrain-telescope-203-2436-mm-OTA.html

Not much needed in the way of accessories except of course for a diagonal and a finderscope. Don’t know of anyone using a reducer although an SCT type should work.

As it uses a crayford focuser that is an advantage for imaging and the fixed primary also helps and has a large illuminated image field of 45mm.

 

I stumbled across your thread of when you first bought this scope and I have to say you’re really selling this to me! Now you’ve had more experience with it would you still say it surpasses the mak 180? I was thinking if it was possible to use a reducer I could still get some wider field DSO Use out of it, with possible AP as well in the distant future. Does a reflector scope like this need a corrector?

This scope seems to be a nice mid-way between the mak and the C9.25 XLT.. take away the long cool down time and dew build up. And it’s currently £200 cheaper than usual.. if I had the money I’d buy it right now. 

Does the scope have anywhere to put a piggyback mount on? I’d like to make more use of my tracking mount and do some Milky Way Photography too. I’ve seen a Celestron one but not sure if they fit all scopes.

[BS269]

37 minutes ago, Cosmic Geoff said:

The lower the object, the more atmosphere the light has to travel through, and the shimmering caused by the atmosphere is correspondingly worse.  Have you noticed how stars near the horizon twinkle more than stars near the zenith? And the lower the object, the more the atmosphere disperses the light into colours, acting like a prism.  This last can be fixed (reversed) using an ADC but the shimmering (=bad seeing) can't be fixed in an amateur situation.   In past years I have obtained useful images with planets at altitudes of 12 degrees or less.

Planets near the horizon can also be blocked by buildings and trees. That's another issue altogether, but one you should check before investing £££'s.  You can check the altitude of the planets at any given time using websites like this one: https://heavens-above.com/PlanetSummary.aspx?lat=52.0406&lng=-0.7594&loc=Milton+Keynes&alt=110&tz=GMT

and use a planetarium program in conjunction with what you can see in the southern night sky to estimate the height of any obstacles.

Or get up at 1 to 2 am this coming morning and take a look. 🙂

Sounds like it’s definitely still possible then! To be honest the most detail I’ve ever seen on Jupiter is Barely being able to make out the Red equatorial bands (is this the right name?) and even then I was blown away 😂 so there isn’t exactly much competition to beat.. I’m just being greedy for the best view possible.

sounds like an ADC is a worthy investment! And my views from where I observe I’d say are very good! There’s one tree that blocks a bit of my view but besides that I can see a lot of the sky in all directions.

thanks very much for this advice!

[Paz]

Of the 3 scopes you mention, I would recommend not going for a newtonian. Setting up a 10" newt on an eq mount will be a major undertaking that will lose it's novelty quickly, and for visual the eyepiece will swing all over the place forcing you to do a lot of "scope-yoga" and rotating of the ota in the rings to be able to use it.

The 180 Mak and c9.25 force you to make choices about observing/imaging objectives. If you want to keep more options open, and there is a lot to be said for that,  then the c9.25 wins (it's extra aperture is also winning). But I'm a big fan of maksutovs so don't tell anyone I said that!

If I was looking for something like this now I would be very interested in the classical cassigrain, the reasons being cool down time and that they potentially entail taking less of a flyer on quality control.

[BS269]

4 hours ago, Paz said:

Of the 3 scopes you mention, I would recommend not going for a newtonian. Setting up a 10" newt on an eq mount will be a major undertaking that will lose it's novelty quickly, and for visual the eyepiece will swing all over the place forcing you to do a lot of "scope-yoga" and rotating of the ota in the rings to be able to use it.

The 180 Mak and c9.25 force you to make choices about observing/imaging objectives. If you want to keep more options open, and there is a lot to be said for that,  then the c9.25 wins (it's extra aperture is also winning). But I'm a big fan of maksutovs so don't tell anyone I said that!

If I was looking for something like this now I would be very interested in the classical cassigrain, the reasons being cool down time and that they potentially entail taking less of a flyer on quality control.

I agree I’m not fond of getting a newt for it. I think the CC and the C9.25” have similar focal length so they should provide similar field of view. If I could use a reducer on the CC that would be great, but without by the sounds of it I’ll get better planetary views.

the CC is my top choice right now, with the mak in 2nd place. Which one I choose between the 2 will depend on How much money I want to spend!

thank you very much everyone for the advice, really appreciate it!

[John]

Many years back I found that an 8 inch F/6 dobsonian provided slightly better planetary views than my Celestron C8 did, rather to my surprise.

Given that the dob cost £150 (used) and the C8 about 5 times that I was happy to let the C8 go and invest in some nice eyepieces for the dob.

Still a big dob fan today