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Cotts
Just Wondering
Reged: 10/10/05
Posts: 906
Loc: Richmond Hill, Ontario
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This scope provides superb views (with a new Paracorr prototype that Al Nagler is working on specifically for scopes from about f/2.5 to f/3.5). Long lineups at Okie-Tex confirmed the quality. f/2.55!! I wouldn't have believed this.... I think the central obstruction is about 30% which isn't too bad...
I hope the designer (in photo) doesn't mind my posting this.
Dave
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David Cotterell
14th Floor Observatory
Richmond Hill, Ontario
200 mm Intes f/10 Mak-Cass
80mm WO Zenithstar FD
66mm WO ED
Losmandy G-11 mount with Gemini
Ioptron minitower
Canon XSi
Edited by werewolf6977 (09/18/09 05:35 PM)
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Cotts
Just Wondering
Reged: 10/10/05
Posts: 906
Loc: Richmond Hill, Ontario
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Here's the info...
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David Cotterell
14th Floor Observatory
Richmond Hill, Ontario
200 mm Intes f/10 Mak-Cass
80mm WO Zenithstar FD
66mm WO ED
Losmandy G-11 mount with Gemini
Ioptron minitower
Canon XSi
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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 Do they come in a 30" model?
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Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn: 
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bgilb
member
Reged: 07/05/09
Posts: 79
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For larger mirrors like 20"+. This is definitely the future. Maybe someone will soon come up with a homemade tester for fast mirrors that is accurate and simple!
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panhard
Mongo
Reged: 01/20/08
Posts: 5186
Loc: Markham Ontario Canada
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Amazing scope Dave.
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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How far off in the future is this for a 20+ size mirror, how will the cost compare to scopes today, how bad does the image suffer? When is the new paracorr coming out? Does it require a new paracorr or also new eyepieces? I think I'm in love. Seriously - how soon for 20+? 
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Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
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Jason D
Post Laureate
Reged: 10/21/06
Posts: 3293
Loc: California
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Such scopes better have the adequate mechanics to fine tune and maintain collimation.
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XT10 classic with premium optics
Tri-knob CR2 with compression rings
Round Table Platform
4.5" StarBlast
6" StarBlast6
TV EPs
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lymorkiew45
professor emeritus
Reged: 12/30/07
Posts: 735
Loc: In the dark, and way out there...
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Thats a unique, and nice scope, but I would think there would be some optical drawbacks besides disaterous coma, without the new paracor, in this design, so I would think the image would not compare to a standard size 14.5" scope, and would suffer greatly simply because of the design...clear skies... 
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Jorgen
Starfinder 16 dob: Zambuto Optics! 
DS-10
Orion XT12i: The optics are special! 
Z12
All the Lanthanum superwides!
Orion ultrablock filter
9mm Nagler type 6
15mm, 25mm, 35mm Ultrascopics
Orion Shorty Plus barlow
Orion Lazer Collimator
40" Webster: Under Construction 
http://cleardarksky.com/c/SanJoseCAkey.html?1
20 years in Southern Dragon Kung Fu, or dragon style embellished in magical arms.
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YankeeJeff
professor emeritus
Reged: 08/11/06
Posts: 537
Loc: Brooklyn, NY
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Well, Cotts thinks the views were superb. Anyone else view through this type of scope yet and care to comment?
Hi Jason - since I don't know much about the mechanics involved, are you saying it would likely be more difficult to collimate, and maintain collimation in a scope like this?
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Oh let the sun beat down upon my face, stars to fill my dream
I am a traveler of both time and space, to be where I have been
24Pan, 17T4, 13T6, 11T6, 9BTMB, 8TVpl, 7T6, 5T6, 3.5T6, 5/6BTMBs
Z10"Dob, Paracorr, 2xBrlw, Telrad, RACI,°Circles, )Spider
FBF, Brooklyn:
Edited by YankeeJeff (09/18/09 05:28 PM)
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Jason D
Post Laureate
Reged: 10/21/06
Posts: 3293
Loc: California
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Quote:
Hi Jason - not knowing much of the mechanics involved, are you saying it would likely be more difficult to collimate, and maintain collimation in a scope like this?
Correct
At F2.55, collimation accuracy needs to be better than 0.2mm. You need adequate mechanics to make fine tweak adjustments to the secondary and primary mirrors. Furthermore, the scope needs to maintain this stringent collimation as you change the ALT of the scope and as temperature changes.
Jason
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XT10 classic with premium optics
Tri-knob CR2 with compression rings
Round Table Platform
4.5" StarBlast
6" StarBlast6
TV EPs
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AV in CMH
sage
Reged: 11/07/05
Posts: 461
Loc: Columbus Ohio
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Is the future for newtonians really a transformation to a CHiefspiegler design?
Shorter,
No obstruction,
Anthony
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Achernar
Postmaster
Reged: 02/25/06
Posts: 5019
Loc: Mobile, Alabama, USA
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No doubt such telescopes would have to be very rigid, otherwise there would be annoying shifts in collimation that do weird things to the views. I'm sure eyepieces will have to be adapted to the very fast focal ratios that are going to be the norm for large telescopes. I don't see this becoming common for 8 or 10-inch Newtonians, it just wouldn't be practical.
Taras
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15-inch F/4.5 Dob under construction
10-inch F/4.5 Discovery Dob
6-inch F/8 Homebuilt Dob
4 1/4-inch F/4 Homebuilt reflector
A whole bunch of eyepieces, filters and other accessories....
Two curious cats
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Cotts
Just Wondering
Reged: 10/10/05
Posts: 906
Loc: Richmond Hill, Ontario
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Dozens of people includiong Al Nagler, Rick of Starmaster scopes and many other very experienced observers were blown away by this scope, not just me. If you want one a bit longer Rick of Starmaster has a 22" f/3.3 here which, with the same prototype paracorr, gives superb views across the field. As for what will be built in the future, check Mike Lockwood's site, visible in the second image I posted upthread. These guys know what they're doing.....
btw I am not connected in any way with this enterprise. Just really impressed.
Dave
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David Cotterell
14th Floor Observatory
Richmond Hill, Ontario
200 mm Intes f/10 Mak-Cass
80mm WO Zenithstar FD
66mm WO ED
Losmandy G-11 mount with Gemini
Ioptron minitower
Canon XSi
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Doug76
Postmaster
Reged: 12/05/07
Posts: 5537
Loc: SE Louisiana, future Texan
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Sounds like amateur versions of the big 8-10 meter scopes the professional observatories use. If it works for them in these short f/ratios, one should figure that proper engineering and corrective optics like the Paracorr being designed for these should work well also.
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Doug
Truckstop Astronomer
The Universe, the light of God, in all it's majesty
6 achro refractors 50mm-150mm
1 apo refractor 90mm
1 SCT 8inch
UO Abbe Volcano Tops
Faworski Ortho's
Panoptic 24mm
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Zoomit
sage
Reged: 12/04/06
Posts: 282
Loc: Tehachapi, CA
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I was observing with Steve Kennedy last month and he brought up an very interesting fact about these forthcoming überfast Newts. In order to get the maximum TFOV out of them, and still have less than a 6 or 7mm exit pupil, you need überwide eyepieces like the Ethos.
In fact, if you have an f/3 mirror, with a Paracorr, a 41mm Panoptic puts out a 12mm exit pupil, a 31mm Nagler puts out a 9mm exit pupil.
The exit pupil with a 21mm Ethos is 6mm.
For the f/2.55 Newt (w/ 1.15x Paracorr) like Mike made, the exit pupil from a 21mm Ethos is 7.2mm.
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Brandon
Newts: 18" f/4.6; 7.4" f/6.4
EPs: TV 26Nt5, 13E, 3-6NZ; Antares 2" 1.6x, Paracorr
Bino: 15x70, 12x50, 6x30
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llanitedave
Humble Megalomaniac
Reged: 09/26/05
Posts: 12932
Loc: Amargosa Valley, NV, USA
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Sounds like you'd want a barlow of some kind to go with them as well.
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"Since the process of science generates more mysteries than it solves, I predict that we'll never learn everything: and we'll continue to generate new ignorance at the speed of knowledge."
"S.O.E." (Sauron's Other Eye), with 16" Royce conical mirror: A permanent work in progress.
10" Homebuilt dob, old Coulter mirror
Under Construction: The "Eye of Sauron" Observatory!
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Zoomit
sage
Reged: 12/04/06
Posts: 282
Loc: Tehachapi, CA
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Good point. Planetary magnifications would need 2-3mm focal length eyepieces.
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Brandon
Newts: 18" f/4.6; 7.4" f/6.4
EPs: TV 26Nt5, 13E, 3-6NZ; Antares 2" 1.6x, Paracorr
Bino: 15x70, 12x50, 6x30
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mark cowan
Vendor (Obsidian Optics)
Reged: 06/03/05
Posts: 2156
Loc: salem, OR
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Quote:
For larger mirrors like 20"+. This is definitely the future. Maybe someone will soon come up with a homemade tester for fast mirrors that is accurate and simple!
Bath interferometer, good down to about f/2.5 at 20". See the Interferometry group on Yahoo for a lot more info.
Best,
Mark
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mark cowan
Vendor (Obsidian Optics)
Reged: 06/03/05
Posts: 2156
Loc: salem, OR
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Quote:
Is the future for newtonians really a transformation to a CHiefspiegler design?
Shorter,
No obstruction,
Chief won't go shorter than f/8 easily, won't go shorter than f/6 at all, SFAIK. These are for the smaller sizes (8" or so) BTW, larger sizes are more restricted. No free lunch.
Best,
Mark
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mark cowan
Vendor (Obsidian Optics)
Reged: 06/03/05
Posts: 2156
Loc: salem, OR
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Quote:
In order to get the maximum TFOV out of them, and still have less than a 6 or 7mm exit pupil, you need überwide eyepieces like the Ethos.
Yeah, that's something Uncle Al concluded as well, in discussing exactly how to go about coma correction at f/3 and below.
BTW Mike told me last month when he was talking about going to Okie-Tex with the f/2.55 that Al was bringing a prototype Ethos as well. Haven't heard any more.  Glad to hear the scope worked well, though!
Best,
Mark
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