Which scope is best for doubles

[leo82]

Hi all, 

I’m planning on buying a new scope and I want to go down the double star route rather than grey fuzzys.

 I was going to get a star travel 120 but research has taught me f ratio needs to be slower, so I thought about the evo star 120.

The thing I liked about the star travel was its size, nice and compact, the evostar is significantly longer. 

So, I thought about a sky max 127 & now I’m back to the beginning not knowing what to get!

Any advice would be greatly appreciated.

[Stu]

Very tricky topic and you will get plenty of advice, anything from a 4" f15 refractor to a 20" dob I should think.

Can you narrow it down by saying what your budget is, whether it needs to be portable and what you plan to mount it on?

Stu

[ronin]

The evostar 120 should be a fairly good option for doubles. Think Bresser do a 127 that could be another option. At the end both are achro's and that makes some limitation. Refractors seem the instrument for doubles, for whatever reason Mak's and SCT's seem little used - maybe the intrinsic field of view is a problem in locating them.

Are you considewring a goto or manual at this stage.

A Stu says give an idea of a budget, this same question came up about 8 months back and out of devilment I said that the William Optics 132 FLT or better still their 152 FLT would be a couple of the best. The 132 starts around £3500, guess the 152 is special order.

Think about potential eyepieces, for clarity you are likely looking at something like the TV plossl range rather then a multielement item like the BST etc.

[leo82]

The straight answer is I don’t know.

For the telescope I’d be looking upto £300, I’m put off by the length of the evostar so I guess as compact as possible, mount depending on telescope I get.

[iPeace]

1 minute ago, leo82 said:

The straight answer is I don’t know.

For the telescope I’d be looking upto £300, I’m put off by the length of the evostar so I guess as compact as possible, mount depending on telescope I get.

Well, you've pretty much answered it then... the Mak 127 should fit your bill. Nice, sharp views, compact, tank-like build, easy to mount and drag around. Very popular.

[Peter Drew]

Cheap, long focus, portable = 127Mak.  

[Mr niall]

I cant give you an objective opinion I'm afraid. But I can give you an opinion on the SW Mak 127 as I've got one! I think it's absolutely brilliant. I'm working my way through "Turn Left at Orion" and have had a go at the most well known doubles up there and haven't come across anything that fazes the Mak yet. I have eyepieces that go up to 250x but I've read about people taking Maks like mine up to 800x (successfully) for certain tricky doubles. Would thoroughly recommend one - the small size and bomb proof construction is another massive plus for me.

Here's my go at the double double recently:

 

[M110]

I'll second the mak suggestion. I have the smaller Skymax 102 and have used it on quite a few doubles over the last few sessions and been impressed with the views considering its a small aperture instrument. I've not found a double so far that I haven't enjoyed the view of.

[chiltonstar]

+1 for a Mak; they are brilliant, and as I remember commenting a few years back, "there's a lot to be said for spherical surfaces"

Chris

[leo82]

Hmmm I guess the mak it’s going to be then.

Does the mak have any problems with the central obstruction? The reason I ask is with my reflector when I look at Mizar, I can/think see it’s companion. However, the spider vane shows up as a spike which gets in the way of the 2 stars?

Thanks.

[iPeace]

1 minute ago, leo82 said:

Hmmm I guess the mak it’s going to be then.

Does the mak have any problems with the central obstruction? The reason I ask is with my reflector when I look at Mizar, I can/think see it’s companion. However, the spider vane shows up as a spike which gets in the way of the 2 stars?

Thanks.

Well, it's there, but I honestly didn't notice it with the Mak 102. Just a nice, refractor-like view.

[Stu]

5 minutes ago, leo82 said:

Hmmm I guess the mak it’s going to be then.

Does the mak have any problems with the central obstruction? The reason I ask is with my reflector when I look at Mizar, I can/think see it’s companion. However, the spider vane shows up as a spike which gets in the way of the 2 stars?

Thanks.

No, the secondary for the Mak is mounted on the corrector plate so there are no diffraction spikes.

I know the benefits of maks, and they are very good scopes. Making sure they are cooled properly is important, as is collimation. In my experience they do not produce star shapes quite as clean as a good refractor but still, the resolution of a 127, 150 or even 180mm Mak is not to be sniffed at. I've never used a 127, my experience is with 140 and 200mm Orion Optics scopes. The 200 took a lot of cooling and often dewed up, but when working well it worked very well. The smaller 127mm will cool much quicker and has an excellent reputation amongst people who use them.

[chiltonstar]

Worth noting that the true aperture is more like 119 mm. 

Chris

[JG777]

A 130mm Newtonian might be all you need, very portable, very cheap,  fast cooling and an excellent performer. Can often be seen beating refractors at their own game.

Bit don't take my word for it the only doubles I observe are in a glass with ice, however this chap seems to know a thing or two..

 http://neilenglish.net/further-newtonian-adventures-with-double-stars/

 

[chiltonstar]

10 hours ago, JG777 said:

A 130mm Newtonian might be all you need, very portable, very cheap,  fast cooling and an excellent performer. Can often be seen beating refractors at their own game.

Bit don't take my word for it the only doubles I observe are in a glass with ice, however this chap seems to know a thing or two..

 http://neilenglish.net/further-newtonian-adventures-with-double-stars/

 

Neil has also "sung the praises" of other scope types for doubles as well, including Maks, eg:-

https://neilenglish.net/the-joy-of-the-maksutov-telescope/

Judging by the posts above, the OP has a newtonian (dob) already and finds the diffraction spikes obtrusive - I can see his point, although scope types are a personal thing, and you always have to accept some compromise or other.

Chris

[Moonshane]

The best scope for doubles is the seeing conditions.

[L8-Nite]

And, if you can find a copy, a most wonderful book which is predominantly on double stars is.......

"In Starland with a Three-Inch Telescope"  by William Tyler Olcott

[Mr niall]

4 hours ago, L8-Nite said:

And, if you can find a copy, a most wonderful book which is predominantly on double stars is.......

"In Starland with a Three-Inch Telescope"  by William Tyler Olcott

That sounds good just did a quick google - another one to add to the list!

[michaelmorris]

If you're after the best bang for your buck for observing doubles have you considered a Maksutov Newtonian?  The Skywatcher offerings are reported to give Apo refractor-like views at a fraction of the cost of an equivalent aperture apo refractor. 

[John]

40 minutes ago, michaelmorris said:

If you're after the best bang for your buck for observing doubles have you considered a Maksutov Newtonian?  The Skywatcher offerings are reported to give Apo refractor-like views at a fraction of the cost of an equivalent aperture apo refractor. 

Agreed. Superb scopes, especially the Russian ones like this (not my advert):

http://www.astrobuysell.com/uk/propview.php?view=131439

Alternatively one of the Orion Optics 140 maksutovs (used) might be within budget or even a used Skywatcher 150 mak-cassegrain if you get lucky.

My personal favourite scopes for double stars are my refractors but those are not within the stated budget.

 

[Timebandit]

 

I consider you have had some great advice on this thread. But personally I much prefer the refractor views on double stars . And have a refractor and reflector so I do not consider myself bias. I just feel the 120ed gives a cleaner crisp view when it comes to doubles.

If you do wish to get it right first time. Personally if it was me I would get along to a star party meet. And have a look through at a few doubles in some of the suggested scopes. You may then wish to hold on a while and save for a different scope choice, as this is usually cheaper in the long run than making a mistake first time round. Also do not rule out purchasing used gear, as a considerable saving can be made. We all are different and our eyes do  prefer certain characteristics of certain targets in certain scope types . But for me it's a refractor?  

[michaelmorris]

I think you should also strongly consider usability in your decision making process.  You should consider such factors as -

Length, weight, height, eyepiece position, vulnerability to high winds, how you are going to mount it, does it need to be easily transportable? etc.

There is an old adage  "The best telescope is the one that gets used the most"

[happy-kat]

You can even mount the 127mm mak straight onto your heritage dob base.

[Dave In Vermont]

There's are very good reasons that the 127mm SW Mak-Cassegrain is the most popular Maksutov over here. The apochromatic-like views, and the 127mm being the maximum size (both physical & aperture-wise) to be considered for a 'grab & go' telescope. A truly powerful instrument in a deceptively small package. Once you've used these, it becomes clear why they were the chosen scope for placement on battle-tanks by the WWII Soviet-Army.

Keeping their clarity and collimation through tank-warfare is no mean feat!

Starry Skies -

Dave

 

 

[Mr niall]

6 hours ago, Dave In Vermont said:

There's are very good reasons that the 127mm SW Mak-Cassegrain is the most popular Maksutov over here. The apochromatic-like views, and the 127mm being the maximum size (both physical & aperture-wise) to be considered for a 'grab & go' telescope. A truly powerful instrument in a deceptively small package. Once you've used these, it becomes clear why they were the chosen scope for placement on battle-tanks by the WWII Soviet-Army.

Keeping their clarity and collimation through tank-warfare is no mean feat!

Starry Skies -

Dave

 

 

Do those soviet ones ever come up for sale anywhere? I’d give my right arm for one!