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Manufactures of good long focaL length refractors

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#26 nightfisher

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Posted 01 February 2013 - 04:13 PM

Just a word of warning regards long focal length fracs, i have an Antares 105 f15 and it is hard on mounts, as a result i dont plan on keeping it, and cant find a buyer for it here in the UK, seems every one wants shorter apo`s

#27 Pete-LH

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Posted 01 February 2013 - 05:49 PM

Actually the D&G 5" f/12 or f/15 price is not so unreasonable ... but the wait is long.
Another route for 4" is to buy a Carton 100mm f/13 lens from S. Favorski and have a refractor constructed by Dan Crawford(same as the maker of the Crawford focuser mentioned above). He does very good work at a reasonable price and is pretty good with respect to timing as well.

http://www.cloudynig...d=classics&a...,,All_Forums,,&Words=&Searchpage=1&Limit=25&Main=5489833&Search=true&where=&Name=71159&daterange=&newerval=&newertype=&olderval=&oldertype=&bodyprev=#Post5497390

You can find a description in the Yahoo Carton group as well. Here is a pic of mine:

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#28 iluxo

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Posted 02 February 2013 - 05:49 AM

There is this http://skylight.mysh.../the-skylight-6

Whether production will resume is an interesting question ...

#29 bremms

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Posted 02 February 2013 - 09:18 AM

Nice, but still 3x the cost of a D&G 6" and you can't get one rigth now. Not too hard to find a used D&G.

#30 ukcanuck

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Posted 02 February 2013 - 03:38 PM

There is this http://skylight.mysh.../the-skylight-6

Whether production will resume is an interesting question ...


There are no production run plans for the Skylight 6, I build them to order only.

The previously mentioned Carton 100/1300's from Sheldon are a good place to start looking for a long refractor. I understood that Sheldon had now sold out (although I could be wrong), but he must have sold quite a few of these objectives over the last two years. :grin: So, it would be worth watching the CN Classifieds to see if any turn up (I guess Astromart would be worth watching too if you can).

Maybe even try a Wanted ad...who knows what you might turn up?

Regarding mounting, I test all my long refractors under 4" on a beaten up Meade LXD55 eq (converted to manual only...no motors). Not 'rock solid'...but perfectly capable. I can deal with some movement at the eyepiece and am in no rush. :imawake:

Long refractors reward the patient...:rainbow:

#31 Bill Friend

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Posted 03 February 2013 - 09:06 AM

Richard,

Is the Skylight 60mm/F15 still available? If not, are you planning to build more in the future?

Cheers,
Bill

#32 Bill Friend

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Posted 03 February 2013 - 09:12 AM

Bart,

Edmund Optics still offers long FL objectives, albeit pricey compared to what you'll find at Surplus Shed. Rumor has it Edmund lenses are fabricated in Taiwan.

http://www.edmundopt...es/large-pre...


Cheers,
Bill

#33 Bart

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Posted 03 February 2013 - 09:19 AM

Where do I begin figuring out what type of lens I should buy?

#34 ukcanuck

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Posted 03 February 2013 - 01:40 PM

Richard,

Is the Skylight 60mm/F15 still available? If not, are you planning to build more in the future?

Cheers,
Bill


Hi Bill, I've sent you a pm.

#35 Bill Friend

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Posted 03 February 2013 - 01:41 PM

Bart,

I think you have to consider the pros and cons of the lens figure/focal length and how you plan to use it. The better the lens figure, the more it will cost. The longer the FL and better color correction, the less portable it will be and the larger mount required. How do you plan to use it? For a quick peeks at the moon and planets you'll want something that's portable w/minimal cool down period (smaller aperture).

Portability is somewhat subjective. One persons 1000mm handy scope is another persons 40" stick that bumps into everything on the way out to the backyard.

Of course budget is another factor that ultimately decides what you can buy.

Cheers,
Bill

#36 nightfisher

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Posted 03 February 2013 - 02:53 PM

Im getting tempted to source an ISTAR 103mm f1200 and drop it into the antares with a crop to the tube, this would get rid of the lens with the chip, and shorten it into a more useful scope

#37 Mirzam

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Posted 03 February 2013 - 04:24 PM

You could set it up for binoviewing at the same time when shortening the tube.

JimC

#38 terraclarke

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Posted 03 February 2013 - 04:25 PM

Why not a Jaegers 103mm x 1575mm F15 air spaced achromat. They are very good lenses. Surplus Shed was selling them but recently sold out, however if you placed a want add you could probably find one.

Terra

#39 starman876

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Posted 05 February 2013 - 09:41 PM

http://www.buytelesc...sv-f11-plane...

here you go hurry if you want one

#40 mikebb

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Posted 06 February 2013 - 08:23 AM

Except for the 2.5" focuser, this Stellavue scope looks very much like the ones being sold by AstroTelescope(599) or Canadian Telescopes(499). Web search for more info.

Mike B

#41 PhilCo126

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Posted 06 February 2013 - 08:25 AM

Thought we were talking classic refractors/telescopes and wanted to suggest the Americans Alvan Clark & John Brashear, the German Carl Zeiss, the Dutch Piet G Meesters, Japanese Unitron ( sold as Polarex in Europe), etc... :doah:

#42 starman876

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Posted 06 February 2013 - 08:30 AM

I do not think they make telescopes anymore :shrug:

#43 terraclarke

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Posted 06 February 2013 - 10:13 AM

It is exactly the same telescope as the one I have, (pictured above)- from Hands on Optics with the exception of the labels and 2 & 1/2 inch instead of 2 inch focuser. The price there has gone up from 499 to 599 recently. They are all three made at Kunming Optical, except Vic checks out the scopes at SV and Gary at HOO. Both, btw, were involved in the original design as I understand it, but Vic baled shortly thereafter as he wanted to focus exclusively on apos.

Terra

#44 PhilCo126

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Posted 08 February 2013 - 12:45 PM

Just kidding... do You know about Peak2Valley in Great-Britain?
http://www.peak2vall...urservices.html

#45 xavier

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Posted 08 February 2013 - 07:42 PM

Just kidding... do You know about Peak2Valley in Great-Britain?
http://www.peak2vall...urservices.html

Very nice people. Contacted them for my Fullerscopes mount. They have classic stock left.

#46 PhilCo126

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Posted 10 February 2013 - 12:00 PM

Check the "New Skylight F15 refractor" topic ...
Skylight refactors:
http://skylight.mysh...kylight-gallery

#47 Jim Curry

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Posted 17 February 2013 - 06:46 AM

I built an OTA from the Istar 4" f/12. Perfect 1/6+ wave optics. It'll cruise at 200x without effort.

Jim

#48 Astro One

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Posted 29 March 2013 - 11:57 AM

To me this doesn't seem cheap. I got on the Hands On Optics sight and started shopping for a complete 4" Astro setup. In my cart I put a Vixen PORTA II mount, the 102 mm f/11 refractor, a stellarvue 50mm finder, a SV F2 mounting base, a SV Red Dot finder, and, SV mounting rings for the F50 finder. Total before shipping comes to $1,129.00! Maybe I am just cheap, but to me cheap would be to go with a 6" F8 Orion reflector. With a dob mount, their 8X50 RACI finder the total is 309.98 + tax, so for me it would cost approximately $335.00, now that is cheap to me. Shipping is free right now with Orion. I have a little reluctance with Orion because I owned their 8" reflector six years ago and though the scope performed well it is definitely built cheaply, it is not a piece of beautiful workmanship like my Obsession 15." My interest in one of these set ups is to view double stars. I have a larger scope for my deep sky work. I see myself using this close to home, sometimes right in my back yard complete with a street light near by; less than favorable conditions. Opinions and suggestions please.
Steve

#49 amicus sidera

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Posted 29 March 2013 - 12:10 PM

My question is this: why is Kunming is not making that 4" refractor at a longer focal length, such as f/15 or even better, f/20? F/11 is too short for that aperture in an achromat, in my opinion.

If I'm going to purchase a refractor, I want a refractor... long tube and near-zero RCA.

#50 Astro One

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Posted 29 March 2013 - 12:31 PM

I'm looking into this!






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