Hi,
Can anyone please share their experiences with a Paracorr 2 using a linear binoviewer in a Dob. What setting would be best. Do you use the settings designated for the eyepiece or a setting for all eyepieces. Thanks for your input.
Jim
That binoviewer must use the included 2X Barlow to move the focal plane out far enough to get it to focus in a newtonian.
I doubt that it will work in a PowerMate, but here is how to tell:
--focus one of the eyepieces in the Paracorr after finding the correct setting for that eyepiece.
If you don't know the correct setting for the eyepiece, insert another eyepiece for which you DO know the setting and focus the scope with that eyepiece.
Then, without touching the focuser, insert the eyepiece you plan to use in the binoviewer into the Paracorr and focus it using the tunable top.
--remove the eyepiece and place it in the binoviewer along with its mate.
--without touching the focuser, put the binoviewer + Barlow in the Paracorr (make certain the Barlow doesn't stick out of the bottom of the 1.25" adapter by more than a couple mm).
--focus the binoviewer by turning the tunable top to focus (you'll have to rotate the binoviewer after it's focused, of course).
--if it came to focus, record the setting and use that setting every time you insert the binoviewer with those eyepieces the next time.
--repeat the 'focus with the tunable top' of the Paracorr for all other eyepiece pairs, recording the settings for each. You will dial the top to those recorded settings every time you use the binoviewer with each pair of eyepieces.
If it does not come to focus at setting A, and you need just a little more in focus of the eyepiece, buy or use a 1.25" adapter on the binoviewer that is a lot shorter than the Paracorr adapter.
The Paracorr adapter is 10.5mm tall above the Paracorr, and there are adapters out there of 1mm height (Baader Push-Fix), -1.5mm (Tele Vue In-Travel adapter) and even more (Astrosystems Ultra Low adapter).
After changing the adapter, focus using the tunable top and binoviewer, after setting it correctly with a single eyepiece and no binoviewer, to get it to focus somewhere in the range of the tunable top.
If it does not come to focus at setting H, and you need a little more out focus, you can gain 6mm with the Tele Vue Hi-Hat adapter (it's 16.5mm tall) or simply by pulling the binoviewer out of the Paracorr until it's in focus.
(after setting the Paracorr properly with a single eyepiece without the binoviewer). If you feel that is unsafe, you can add a barrel extender to the Barlow to allow you to safely pull the binoviewer farther out.
If that isn't sufficient, either way, you cannot use the binoviewer in the Paracorr. You might be able to use it without the Paracorr, in that case.
Remember, every pair of eyepieces will take a different setting of the Paracorr unless your different pairs of eyepieces are parfocal.
Edited by Starman1, 03 March 2024 - 05:13 PM.