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To refract or reflect?


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OK gang, so after listening to your advice on a previous topic (basically spend a bit more if I can afford it) I have upped the budget a bit from around £150- £175 to about £200 (can't afford any more).

At this sort of price point, what are the merits of a refractor or a reflector?

My goals are studying the moon, looking at the planets and hunting for galaxies etc. I would like to image eventually, not now sure if this would be by way of DSLR or a webcam.

Back yard set up with occasional trips to rural common land to escape the light pollution.

Thanks folks.

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I would go manual reflector and worry about imaging later. The quality of the reflector is going to be better (not to mention bigger) than an equivalent cost refractor/tripod/mount. A decent sized Dobsonian at this price point every time for me.

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Useful refractors start around £350 for an appo doublet of about 70mm to 80mm and that is "scope only" I.e. no mount. Achros are a little cheaper but you will get spherical abberation and fringing. So really it's academic that a reflector would be the choice for your budget.

Get the largest aperture you can and the most appropriate mounting - for me that would either be a brand new 150P on a dobsonian base - or a second hand 200P Dobsonian. If you can find a good second hand 8" dob you wouldn't regret it. :)

(Check SGL classifieds or UK Astro buy/sell - probably the best two places to look).

Edited by brantuk
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Ignoring everyone, Which do you actually want?

Which one in your mind do you see yourself looking through. A post some time back coverd this and said to get the one you want as there is a greater chance of you using it the most.

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Tricky choices - from experience I'd say that it's a good idea to have a general purpose scope.  Your budget will restrict you to something fairly simple - or a lucky second-hand purchase.  For the Moon and planets you can get away with a scope of modest size on a fairly basic mounting. At high resolutions the blurring effect of the atmosphere dominates which means that the actual performance of larger apertures compared with their theoretical performance is usually disappointing (unless you are on a mountain top.) I've noted that some experienced planetary observers recommend an expensive ED or APO refractor of modest aperture.  The rest of us just use what we've got.

Unless you become a planet specialist, looking at them will not take up much of your observing time, so it would be desirable to have a telescope that works for deep-space objects as well. For galaxies, star clusters, nebulae and globular clusters, large aperture is a decided advantage.  It is also a decided advantage to have GoTo, otherwise you may suffer the frustration of knowing that your telescope will show you many fine objects if you could only find the damn things.  

On the planetary front, GoTo is also a massive time-saver for looking at Uranus and Neptune which can be tricky to locate otherwise, given that they are faint and look star-like at low magnification.  With GoTo you can also locate the brighter planets in daytime.

Reflector or refractor? Refractors don't have a central obstruction and should out-perform a reflector of the same aperture. But they become very expensive as the size goes up. Your choice.

Focal ratio - a feature rather than a problem.  It becomes an issue if you need an eyepiece to give high magnification on a f5 scope, or want to view one of the large deep-sky objects (rather few in number) with a f12 scope and find it won't fit in the LP eyepiece field.

Mountings - some amateurs clearly prefer the simplicity (and low cost) of the basic unpowered alt-azimuth mountings, while others would not be without their powered equatorial mounts or their GoTo.  Your choice.

 

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Thanks for the input CG- much appreciated.

I have a sneaking suspicion I should have grabbed the bull by the horns and taken the plunge last night on this- http://www.ebay.co.uk/itm/201770474750?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Came to look at it this morning and BOOM! beaten to it:hmh:

I am going to attend my local societies' Telescope Night tonight- who knows, someone may be looking to offload something.

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