astrodon
Carpal Tunnel
Reged: 04/07/05
Posts: 2552
Loc: Portland, OR, USA
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Lawrence-
In the photo of the Paracorr with the tunable top you can see that setting 5 is the lowest, for in order to reach that setting the tunable top with the slot in it must descend in order for the set screw to reach that level.
Hope I helped to clear this up, I know it is hard to get just by looking at the image,
~Don
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Eager to get the Cave 6" f/4 out with some 'high' (medium in this scope) power eyepieces!
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Lawrence Sayre
Abbe Normal
Reged: 10/16/04
Posts: 5128
Loc: N.E. Ohio
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OK, I finally realize that my intuitive view of the 5 being higher in the picture than the 1 was all wet, and I now trust that 5 is the lowest and 1 is the highest setting. Obviously the slide lever has to go up for the tunable top to go down, and visa versa. Thank you Don and Don!!! With that to go on, I've re-worked my spreadsheet once again, and I'm attaching it right here. I'm also now willing to believe that the TeleVue website chart is using the taller adapter for its 1.25" eyepieces. Please kick the tires with this spreadsheet, and let me know if it gives correct tunable top settings across the board.
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My philosophy, in essence, is the concept of man as a moral being, with his own happiness as the moral purpose of his life, with productive achievement as his noblest activity, and reason as his only absolute.
Ayn Rand (in the appendix to 'Atlas Shrugged')
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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Posts: 17639
Loc: Los Angeles
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Lawrence,
It worked for my 31 Nagler and my Type 6 Naglers.
It didn't work for the 17 Nagler, with a field stop to shoulder dimension of -0.03"
The spreadsheet erroneously gives a setting of 5 instead of 3.
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Don Pensack
www.EyepiecesEtc.com
12.5" Teeter/Zambuto, 5" Maksutov
Sustaining Lifetime IDA member
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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Posts: 17639
Loc: Los Angeles
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Lawrence,
I accidentally included the adapter height for a 2" eyepiece.
Doh! 
Your calculator works fine.
Don
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Don Pensack
www.EyepiecesEtc.com
12.5" Teeter/Zambuto, 5" Maksutov
Sustaining Lifetime IDA member
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Lawrence Sayre
Abbe Normal
Reged: 10/16/04
Posts: 5128
Loc: N.E. Ohio
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Thanks!!!
Whew, you had me worried there for a bit. I was beginning to wonder if I would ever get it right. A sanity tester for sure.
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My philosophy, in essence, is the concept of man as a moral being, with his own happiness as the moral purpose of his life, with productive achievement as his noblest activity, and reason as his only absolute.
Ayn Rand (in the appendix to 'Atlas Shrugged')
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Keith
sage
Reged: 05/14/05
Posts: 467
Loc: Costa Mesa, CA USA
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for the 30mm 1rpd, setting 3, works suprisingly well. When I later aquired the real deal 30mm widescan III, suprisingly, it wasnt as well correctable with the paracorr, possibly because it has a wider field stop. I kept both eyepieces. Since I also aquired a nice f10 OTA, I use the WSIII with it, and my most recently aquired 31mm nagler with the dob, with or without the paracorr. I have the older photo/visual model, and the vignetting bothers me, so I will likely add the visual model in the future, and keep the other for my 8"f4 for imaging.
my 2c in the 8.8 UWA discussion, I used it in the lowest setting (5) with the included 1.25 adapter in 1.25 mode, like suggested for the 9mm nagler and it worked very well. I dont think I tried it with the 14mm yet, which I aquired more recently.
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Cats (tubes): C11xlt, 8"Meade"R", Orion Apex90
APOs: TV101, Pronto(semi-apo)
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ACHROS: C102, Nexstar 80GTL
Mounts: CG11G, CG5-RA, SV M3
ST7XME, Pixcel255
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recovering eyepiece junkie
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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Posts: 17639
Loc: Los Angeles
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I went back and looked for my records:
14mm UWA (used as 2")--setting 1
8.8mm UWA (used as 2")--setting 5
The 31 Nagler would be better corrected at setting 6. The fact there is no setting 6 shows the Paracorr was designed long before the 31 Nagler. I find it "tolerable" with setting 5, however. 
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Don Pensack
www.EyepiecesEtc.com
12.5" Teeter/Zambuto, 5" Maksutov
Sustaining Lifetime IDA member
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Zooball
journeyman
Reged: 02/05/07
Posts: 9
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Thanks Don,
You just saved me a lot of work. I have both of those EPs and a brand new Paracorr PCV-2000 still snug in the box waiting for dark skies.
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sixela
Postmaster
Reged: 12/23/04
Posts: 13991
Loc: Boechout, Belgium
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Quote:
I woke up early this morning and I've been attempting to make a spreadsheet to calculate the ideal Paracorr tunable top setting based solely upon the field stop location of the eyepiece, and although in its present state it appears to give correct answers for all of the 2" TeleVue eyepieces, it gives incorrect answers for all of the 1.25" TeleVue eyepieces.
Probably means you haven't accounted for the extra 9.6mm caused by the Paracorr 2"-1.25" adapter.
Edit: never mind - late to the party...
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400mm f/4.46 self made Dobsonian on Tom Osypowski equatorial platform
Skywatcher 130mm f/5 BlackLine (finder, widefield scope and solar continuum scope)
Sumerian 250mm f/4.8 Alkaid (as travelscope without platform and on Tom O. platform above).
Edited by sixela (08/28/07 11:56 AM)
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bkushner
Carpal Tunnel
Reged: 11/26/06
Posts: 1807
Loc: Audubon New Jersey
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What about Ethos?
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Orion XT12i
Meade LX200 ACF
Ioptron Mini Tower
Orion EON80
Mallincam Hyper Plus
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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Posts: 17639
Loc: Los Angeles
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The position of the Ethos' focal plane is only 0.02" different than the Type 6 Naglers. That means setting 4 would be correct--the Nagler Type 6s WITH the adapter, and the Ethos WITHOUT an adapter.
I don't believe you could get the Ethos close enough to the Paracorr lens if used with a 1-1/4" adapter.
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Don Pensack
www.EyepiecesEtc.com
12.5" Teeter/Zambuto, 5" Maksutov
Sustaining Lifetime IDA member
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sixela
Postmaster
Reged: 12/23/04
Posts: 13991
Loc: Boechout, Belgium
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Can't. In 1.25" mode in a 2"-1.25" adapter, it doesn't insert with the 1.25" barrel completely seated in the adapter, because the 2" barrel contacts the adapter.
When used this way, the focal plane is much too far from a Paracorr lens, even with a zero-length adapter.
Ethos: 2" mode, top fully pulled out.
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400mm f/4.46 self made Dobsonian on Tom Osypowski equatorial platform
Skywatcher 130mm f/5 BlackLine (finder, widefield scope and solar continuum scope)
Sumerian 250mm f/4.8 Alkaid (as travelscope without platform and on Tom O. platform above).
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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Posts: 17639
Loc: Los Angeles
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It works fine in a TeleVue "High-Hat" 1-1/4" adapter, but, in general, the Ethos should be used as a 2" eyepiece in 2" focusers. And in the Paracorr too.
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Don Pensack
www.EyepiecesEtc.com
12.5" Teeter/Zambuto, 5" Maksutov
Sustaining Lifetime IDA member
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Mr. Bill
Postmaster
Reged: 02/09/05
Posts: 5219
Loc: Northeastern Cal
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Anybody know offhand what the settings for the 14, 10.5 and 7 mm Pentax XLs is?
I say "is" because they are all parfocal.
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The night sky is the palette....
My optics are the brushes....
The Milky Way is the masterpiece
Member IDA
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sixela
Postmaster
Reged: 12/23/04
Posts: 13991
Loc: Boechout, Belgium
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Quote:
It works fine in a TeleVue "High-Hat" 1-1/4" adapter,
That doesn't fix the issue either, because the reason it works is because the high-hat adds extra length.
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400mm f/4.46 self made Dobsonian on Tom Osypowski equatorial platform
Skywatcher 130mm f/5 BlackLine (finder, widefield scope and solar continuum scope)
Sumerian 250mm f/4.8 Alkaid (as travelscope without platform and on Tom O. platform above).
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Mr. Bill
Postmaster
Reged: 02/09/05
Posts: 5219
Loc: Northeastern Cal
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Quote:
It works fine in a TeleVue "High-Hat" 1-1/4" adapter, but, in general, the Ethos should be used as a 2" eyepiece in 2" focusers. And in the Paracorr too.
That's what TV's Ethos instruction sheet plainly says....
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The night sky is the palette....
My optics are the brushes....
The Milky Way is the masterpiece
Member IDA
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Starkler
scholastic sledgehammer
Reged: 11/04/05
Posts: 785
Loc: Australia, Melbourne
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Quote:
Anybody know offhand what the settings for the 14, 10.5 and 7 mm Pentax XLs is?
I say "is" because they are all parfocal.
The Pentaxs appear to perform best with the tunable top set to the highest setting (which requires the max amount of focuser in-travel). I had to cut 15mm from my truss poles to accommodate but its worth it 
I find the paracorr works wonderfully as a field flattener, nicely mitigating the often criticised field curvature in the 14 and 21mm pentaxs
A note of caution! A friend handed me an OIII filter to try on my 31nagler. Dont try it as it hits the paracorr lens
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Geoff
15" SDM truss dob | Vixen r130sf | GSO 10" dob
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Starman1
Vendor (EyepiecesEtc.com)
Reged: 06/24/03
Posts: 17639
Loc: Los Angeles
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Quote:
A note of caution! A friend handed me an OIII filter to try on my 31nagler. Dont try it as it hits the paracorr lens
Ouch.
Note: 2" filters should be threaded on the bottom of the Paracorr for safety's (and convenience's) sake.
And don't use 1-1/4" filters on the bottom of the dual 1-1/4"/2" eyepieces when used as 2" eyepieces either. The filter will hit the lens if a lower setting is used.
If you use a Paracorr, it is safer to use all 2" filters and thread them on the bottom of the Paracorr.
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Don Pensack
www.EyepiecesEtc.com
12.5" Teeter/Zambuto, 5" Maksutov
Sustaining Lifetime IDA member
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Olivier Biot
Amused
Reged: 04/25/05
Posts: 24589
Loc: 51°N (Belgium)
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For that reason I'm designing a 2" filter wheel that goes right below the ParaCorr.
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I think you're worth a double serving of happiness!
Tal-200K (#199) with JMI NGF-Mini2M focuser on GEM3 • Astro-Tech AT80ED • Orion Sirius EQ-G with wireless EQDIRECT • Astro-Tech Voyager • Celestron Regal LX 10x42 • Helios 15x70
ATM projects: 14" f/5 truss Dobson: first light Jul 1, 2011  - currently in 'tweak & widget' mode 
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Shawn H
Postmaster
Reged: 05/16/07
Posts: 6692
Loc: Equatorial Guinea, West Africa
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Lumicon sells thier coma correcter for about 100 euros less than TV's paracorr in France, I'd love to hear if anyone has done a side by side comparison!
Shawn Haggerty Avignon, France
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18" David Lukehurst truss Dobson with Sky Commander flash 4 DSC's & Moonlite CR2 focuser & Astrocrumb filter slide
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