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Using Original Paracorr - tips?

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#1 zakry3323

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Posted 07 December 2018 - 10:21 AM

Long story of kindness and generosity short, a CN member gifted me an original Paracorr to give my dad for Christmas to use in conjunction with his eyepieces on his F/4.5  16" Lightbridge. 

I've been on TeleVue's website...and can only find instructions for the Paracorr Type 1/Type 2. 

The original does not have a tunable top, and I'd like to try to help him figure out how to get the spacings correct for his various EP's. 

If anyone has any tips, or can share a scan of the instructions (Did it come with instructions?), I'd really appreciate it!

Nope, I'm not going to buy the ATT-2125 Tunable Top separately: I'm spending the remaining Christmas budget on some other fun upgrades for him :)

Thanks!



#2 csa/montana

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Posted 07 December 2018 - 10:26 AM

This thread is moving to Equipment for better fit of topic, and more assistance.


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#3 Jon Isaacs

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Posted 07 December 2018 - 11:21 AM

Zakry:

 

I have owned all three Paracorrs (actually 4 if you include the 1.25")

 

This the way I see the original Paracorr without the Tuneable Top:

 

The spacing was designed to correct the coma in the 1.25" TeleVue eyepieces as well as the 2 inch eyepieces of the time.  The 2 inch eyepieces would have been the 20mm Type 2 Nagler, the 32mm and 40mm WFs and maybe the 35mm Panoptics.

 

In any event, these 2 inch eyepieces all require a tall spacing.  With the Tuneable Top, it's nearly fully extended.  Few eyepieces require more extension and for those that require a more inward position, there's not much you can do about it.

 

In terms of 1.25 inch eyepieces, I think the spacing is close for most 1.25 inch TeleVue's.  In my experience, other eyepieces require a little more inward focus, not much you can do about it.

 

So I think the short story is that you just use it and don't worry about it.  It might not be optimal but it will be quite good.  I remember looking up the flange to focal plane spacings for the Explore Scientific eyepieces.  The 20mm 100 degree requires an inward position like the 31mm Nagler, 21mm Ethos but otherwise, they all seemed to spaced outward like the 35mm Panoptic. 

 

Jon



#4 zakry3323

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Posted Yesterday, 03:04 PM

Zakry:

 

I have owned all three Paracorrs (actually 4 if you include the 1.25")

 

This the way I see the original Paracorr without the Tuneable Top:

 

The spacing was designed to correct the coma in the 1.25" TeleVue eyepieces as well as the 2 inch eyepieces of the time.  The 2 inch eyepieces would have been the 20mm Type 2 Nagler, the 32mm and 40mm WFs and maybe the 35mm Panoptics.

 

In any event, these 2 inch eyepieces all require a tall spacing.  With the Tuneable Top, it's nearly fully extended.  Few eyepieces require more extension and for those that require a more inward position, there's not much you can do about it.

 

In terms of 1.25 inch eyepieces, I think the spacing is close for most 1.25 inch TeleVue's.  In my experience, other eyepieces require a little more inward focus, not much you can do about it.

 

So I think the short story is that you just use it and don't worry about it.  It might not be optimal but it will be quite good.  I remember looking up the flange to focal plane spacings for the Explore Scientific eyepieces.  The 20mm 100 degree requires an inward position like the 31mm Nagler, 21mm Ethos but otherwise, they all seemed to spaced outward like the 35mm Panoptic. 

 

Jon

 

Perfect, this is everything I needed to know! Thanks a lot!!


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