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minty
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hi ive got a 114mm newtonian scope but would like advice on min specs to get good detailed views of planets, should i go for another newtonian? what size? or should i go the dobsonian rote? all advice will be welcome as i wish to make a well informed purchase of a new scope. thank in advance to all who can help. :clouds2:

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Welcome Minty,

The answer really depends on the budget! If cost is a factor then a 8" F8 Dob will do the trick I think. If not maybe a SCT or APO refractor - but then you're talking loads a money :clouds2:

Are you going to be wanting to take images in the future....? If so then the mount is vital and a dob won't do.

Cheers

Ant

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... would like advice on min specs to get good detailed views of planets, should i go for another Newtonian? what size? or should i go the Dobsonian rote?

Welcome aboard Minty,

For planets, you will need a long focal length (for higher magnification) and a small central obstruction (for greater contrast).  The two together produce a 'slow' focal-ratio ... about f8 or more.

There aren't many Newtonians that fit the bill though the new Orion Optics (UK) Europa 150 f11 springs to mind:

http://tinyurl.com/7rxpz

Alternatively, consider a Maksutov Catadioptric with at least 4" of aperture.  Something like this:

http://tinyurl.com/azb33

Or this:

http://tinyurl.com/cmxo4

Or, if you have really deep pockets you might consider this:

http://tinyurl.com/dfjcq

It does of course depend on your budget and other requiremants you might have.

Hope that helps,

Steve :clouds2:

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welcome Minty , a sct for me at F10 and can be reduced for DSOs as well and all round good performer, i use the Celestron GPS8 have two of them , the drives are very accurate and the scope performs very well , the go to system is spot on , and the optics are good as well ,

Cheers

Rog

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You've had lots of advice, but that doesn't stop me from putting my oar in. I have a 114mm reflector. Infact, I have two. I started with a Meade f/8, and as I got more sophisticated, I realized that I had a problem with my mirror, to wit: it was a spherical mirror, not a parabolic one. I had already improved my views dramatically by buying better eps, and whe I went to a star party last year, an American correspondent of mine brought along his Tasco 4.5". I had a look through it, and it was immediately obvious that the view was much better at high magnifications (>150x) So I bought it, and now use it almost exclusively. I have been able to see detail on Mars, and much detail on Jupiter. The Cassini division in the rings of Saturn still eludes me, but I can sometimes see surface markings on Saturn. Either of the two scopes is fine for DSOs, within the limits of magnitude.

You can doe quite a lot with that scope, with some extra eps and patience.

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Hi Warthog, you make some interesting points...

... I realized that I had a problem with my mirror, to wit: it was a spherical mirror, not a parabolic one.

A spherical mirror isn't always an indicator of poor performance.  The TAL-2 has a spherical mirror that produces excellent results and because spherical systems are far less subject to mis-alignment, it requires periodic alignment only.   

... correspondent of mine brought along his Tasco 4.5". I had a look through it, and it was immediately obvious that the view was much better at high magnifications (>150x) So I bought it, and now use it almost exclusively. I have been able to see detail on Mars, and much detail on Jupiter. The Cassini division in the rings of Saturn still eludes me, but I can sometimes see surface markings on Saturn.

This is curious?  A 4.5" should easily be able to see the Cassini division in Saturns rings.  At first, I wondered whether it was a contrast problem but, if you can see detail on Mars, in Jupiter's weather bands and the surface of Saturn .... I'm flummoxed :scratch:

Steve

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Hi Warthog, is it not just down to seeing conditions? when did you look at the planets was it on the same night sometimes i cant see the cassini either through a 5" APO THEN OTHER TIMES I SEE IT WITH EASE So i am wondering if that is the case the seeing can change very quickley Tom.

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