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List of Paracorr settings for all brands of EP's

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#201 Starman1

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Posted 02 December 2013 - 12:26 AM

Anyone input the Delos line into the settings?

All the Delos eyepieces except the 17.3 and 14 will use setting "D" with the Paracorr's supplied 1.25" adapter.
The 17.3 and 14 will require setting "A" for right now, also using the 1.25" adapter.
There may be another, lower-profile, 1.25" adapter for the 17.3 and 14.0 a little later on, as the "perfect" correction for those two will require a setting a little farther in than setting "A".
But "A" will still correct a lot better than no Paracorr, in the same way that the original Paracorr didn't completely correct the 31 Nagler or 21 Ethos but they still were improved a lot over no Paracorr.


Don, will the 17.3/14 Delos only come close to working optimally with the Type 2 ParaCorr? I tried both in my Type 1 (PCV-2000) on setting 1 and the 14 Delos edge performance compared to the XW 14 left much to be desired in the f/4.3 STS 11.


TeleVue now makes an "In Travel" adapter that drops the shoulder of the 17.3 and 14 Delos 1/8" below the top of the Paracorr. If the 17.3 and 14 are used with this adapter, they become parfocal with the 12-3.5mm range when those are used with the standard adapter that comes in the Paracorr.
If there is an optimum setting for the 3.5-12mm Delos in the Paracorr 1 (and they would all use the same setting), the use of the In-Travel adapter will allow the 17.3mm and 14mm to use the same setting as all the other Delos eyepieces.
Since the short focal length Delos are parfocal with most of TeleVue's 1.25" eyepieces, and none of them used setting 1 in the original Paracorr, the key is to use the correct setting for the other 1.25" eyepieces (I can't remember if it was setting 2 or 4 when using the supplied 1.25" adapter) and use that same setting for the Delos range.
If the 17.3mm and 14mm Delos are then used with the new adapter, that setting would also be optimum for them.

#202 Starman81

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Posted 02 December 2013 - 11:38 AM

TeleVue now makes an "In Travel" adapter that drops the shoulder of the 17.3 and 14 Delos 1/8" below the top of the Paracorr. If the 17.3 and 14 are used with this adapter, they become parfocal with the 12-3.5mm range when those are used with the standard adapter that comes in the Paracorr.
If there is an optimum setting for the 3.5-12mm Delos in the Paracorr 1 (and they would all use the same setting), the use of the In-Travel adapter will allow the 17.3mm and 14mm to use the same setting as all the other Delos eyepieces.
Since the short focal length Delos are parfocal with most of TeleVue's 1.25" eyepieces, and none of them used setting 1 in the original Paracorr, the key is to use the correct setting for the other 1.25" eyepieces (I can't remember if it was setting 2 or 4 when using the supplied 1.25" adapter) and use that same setting for the Delos range.
If the 17.3mm and 14mm Delos are then used with the new adapter, that setting would also be optimum for them.


Thanks Don. The setting for 1.25" TV eyepieces in the ParaCorr Type 1 is setting 4, so I'll have to try them out with the In-Travel adapter.

#203 Phillip Creed

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Posted 07 April 2014 - 07:34 PM

Paracorr Type-1:

30ES-82: Setting ~ 1.7 (closer to "2" than to "1").

This would put it at around the same setting as a 20T5, if you're thinking about a Baader MPCC for this eyepiece.

Clear Skies,
Phil

#204 charles genovese

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Posted 26 September 2014 - 02:02 PM

My understanding of coma correctors is they should be a fixed distance from the primary ( or correspondingly a fixed distance inside the focal plane). Therefore th proper way to do this is to set the focuser to maintain the paracor at the proper location and actually focus using the paracor tunable top!

#205 MSWcdavis

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Posted 14 January 2015 - 08:35 PM

I haven't read anything about paracorr settings for the 30mm 82degree Explore scientific eyepiece.  Any suggestions anyone (type 1 paracorr for 32mm ES 82)


Edited by MSWcdavis, 14 January 2015 - 08:36 PM.


#206 star drop

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Posted 15 January 2015 - 10:02 PM

I haven't read anything about paracorr settings for the 30mm 82degree Explore scientific eyepiece.  Any suggestions anyone (type 1 paracorr for 32mm ES 82)

Post number 203 by member Phillip Creed, two posts above yours in this thread answers your question.



#207 MSWcdavis

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Posted 15 January 2015 - 10:37 PM

 

I haven't read anything about paracorr settings for the 30mm 82degree Explore scientific eyepiece.  Any suggestions anyone (type 1 paracorr for 32mm ES 82)

Post number 203 by member Phillip Creed, two posts above yours in this thread answers your question.

 

 

sorry i searched the thread with explore scientific not "ES" - didn't see that post

 

my bad



#208 MSWcdavis

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Posted 16 January 2015 - 09:01 PM

another simplistic question

 

what is the first mark on a paracorr?

 

is it the lowest mark, or the highest?

 

 

does it go 1,2,3,4,5

or 5,4,3,2,1

 

i'm assuming the former but want to check



#209 star drop

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Posted 17 January 2015 - 09:58 PM

Mark one is the longest configuration and mark five is the shortest configuration.



#210 Starman1

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Posted 18 January 2015 - 11:49 AM

My understanding of coma correctors is they should be a fixed distance from the primary ( or correspondingly a fixed distance inside the focal plane). Therefore th proper way to do this is to set the focuser to maintain the Paracorr at the proper location and actually focus using the Paracorr tunable top!

Yes, but the coarse focusing by the tunable top, though fine for finding the correct setting for an eyepiece, isn't quite fine enough for focusing in any scope short enough to need a Paracorr.

You'll still end up using your focuser.  Because if you don't use your focuser, you;ll never achieve the very finest of focus.

And once you've used your focuser, even for a millimeter of movement, the Paracorr won't be at the optimum position any more.

So we "pre-dial" the settings for the eyepieces and tweak the focuser for best focus.

Plus, many eyepieces' best settings are in-between settings on the Paracorr.  It's unlikely that you'll pre-set the Paracorr's top to "D+" for instance.

So, after recording all the best settings for your eyepieces, you'll round them off to the nearest letter and just dial in the focuser.

That only results in about 2mm of focuser travel, which isn't significant for coma correction.

 

It might interest you to know that eyepieces TeleVue says are parfocal on their specifications list are not actually parfocal.  The term parfocal means the eyepieces

focus at approximately the same point, not that they focus at EXACTLY the same point.  So two eyepieces that are listed with the same Paracorr setting may require a slight tweak of the focuser to bring them to focus.  Ideally, the Paracorr's tunable top would be moved slightly but in practice one doesn't do that.

 

It can be easier to adjust the Paracorr's top if all your eyepieces are made parfocal before using the Paracorr.  That way, since all your eyepieces use the same setting, you won't even need to adjust the Paracorr's top unless you borrow an eyepiece.  To parfocalize your eyepieces, you start with your eyepiece that needs the most in-focus of all and freeze the focuser at that point.  Then, add spacers and barrel extenders and parfocalizing rings to your other eyepieces to put them in focus at the same setting of the focuser.  When all your eyepieces are in focus at the same position of the focuser, they are all parfocal.  After that, they will also all use the same setting on the Paracorr.

I didn't do that completely, as two of my 7 eyepieces use the in-most setting of the Paracorr, while 5 use the out-most setting.  That was easy to remember.




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