Quote:
Originally Posted by Wavytone
Chris...
First question is whether you are interested in wide field photography, or are a visual observer (i'm a visual observer, no AP whatsoever). For AP focal ratio is the first priority where "average" image quality over a wide field will do, but visual observations of close double stars, lunar & planetary - these are all about image quality (resolution) on-axis.
A few years ago I sold all my gear and, in a bout of refractoritis, I bought a TS 130mm f/7 triplet APO to see what all the fuss was about. A significant aspect in my case is that my first "real telescope" was a superb refractor - a Thomas Cooke 4.25" f/15 on a beautiful bronze clockwork mount. Not only a beautiful antique, but one that works superbly. The TS 130mm refractor was very nice, optically everything you would expect.
However... one night I did a side-by-side comparison with a C5 and an old-school 15cm f/8 newtonian. Sorry refactor guys, stop reading here. At the same magnification the refractor and the C5 were indistinguishable... it's true. However the refractor didn't fare so well compared to the 15cm Newtonian - which had perfect optics and slayed the refractor on Jupiter at high power.
A few months later a Skywatcher 180mm f/15 Mak was advertised here on IIS which was optically 9/10 and cost ⅓ the price of the refractor. Side-by-side with the 130mm refractor, the Mak killed it on every object, bar none. Bang-per-buck, the mak was a clear winner. Always.
At X2 per mm (260X) on double stars the refractor was good. On the trapezium in Orion, E and F stood out in the mak but the refractor struggled.
Ultimately, in 2016... an acquaintance in the US decided to part with a rare scope - a Santel MK91. I had met the owner and the scope many years ago and when he decided to sell it I leapt at it.. However not cheap and I sold all my gear - the refractor, SW Mak, mount and eyepieces to fund this, AND mount a new mount to put it on.
No regrets... optically this scope kills Questar 7's, 10" and 11" SCTs.
In retrospect IMHO the SW 180mm Maks are a bargain - optical quality appears to be consistently better than 20cm SCTs, and its a perfect size and weight for a portable scope.
Stepping up to a 9" or larger scope is problematic - the weight and focal length are both significant and pose challenges that may be beyond some owners.
As for a 9" refractor ... that is way beyond portable.
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Ha! 9" refractor. I hit the gym fairly often, but even so... yeah nah.
Thanks for the stories, sounds like you've spent a lot of time looking through the different types. I've never attended a star party so the only scopes I've ever looked through are those I've owned. Would love a chance to experience something other than mine, particularly something that cost real money, just to see what the differences are.
I'm curious, though. When it comes to visual observing, aren't all telescopes basically limited by seeing conditions? I mean, wouldn't it take truly exceptional conditions to experience a significant benefit of one over another? Isn't sharpness very strongly affected by atmospheric blurring, isn't contrast affected by light pollution? Are the differences only really visible under perfect conditions?
Personally, I'm mainly interested in AP, which is why I got the Newts in the first place - they're supposed to be the best bang for an AP's buck. I was just surprised to learn that the bigger, heavier, faster Newt was actually only bigger and heavier - without actually being faster at all!
Having said that, I've got a 5-yr-old little girl who LOVES looking at the planets, so maybe there will be increased visual use in years to come.