AS of NSW
AS of Hunter Valley
Fact: I like reflectors and big ones. All the refractors I own are either finderscopes, binoculars, or riflescopes.
18"/F4.5 Obsession #1333 fully optioned (OMI Optics)
14"/F4.5 SDM #33 fully optioned (Zambuto Optics)
10"/F5.3 SDM #50 fully optioned (Suchting Optics)
Pentax XW's, T4 & T5 Naglers , UO HD orthos, 6mm Delos, 8mm Radian, 8.5mm Pentax XF, 13mm Ethos. 12mm Celestron Illum Astrometric eyepiece. Rainbow Optics Spectroscopic Eyepiece Set. Orion Optics UK 250 lpi Ronchi grating eyepiece. 2" Astronomiks UHC, OIII & H-Beta filters, 2" DGM Optics NPB filter. 2" Variable Polariser. 2" Hoya colour filters.
Leupold 10x42 & Pentax 16x60 binos.
Quote: I was going to get SIPS on my 11" F/5 Teeter STS with Zambuto optic but after concerns with barlowing decided a Paracorr 2 would suit me best. It turns out that SIPS can only be used with a barlow that's parfocal with the eyepiece used in it. For me that works out to a grand total of one A team eyepiece with 5 barlows which is far from ideal. With the adjustable Paracorr I should be able to use at least some eyepiece barlow combos that aren't parfocal. I probably wouldn't use the Paracorr when barlowing most of the time and it's much easier to take out than the SIPS. I'll buy from Astronomics so they can get in on my newt action. I bought an excellent passive-laser collimation set on CNC so no sale for them there. As to the newt Rob says we are waiting for the optic with June is still the ETA! David
Quote: You misunderstood what "SIPS can only be used with a barlow that's parfocal with the eyepiece used in it" meant.
Quote: Quote: You misunderstood what "SIPS can only be used with a barlow that's parfocal with the eyepiece used in it" meant. So here's a question for you Don:If one thinks of a Barlow and an eyepiece as a new, unique eyepiece, why is it that you can't just focus it as you would any other eyepiece? Jon
Quote:Quote: Quote: You misunderstood what "SIPS can only be used with a barlow that's parfocal with the eyepiece used in it" meant. So here's a question for you Don:If one thinks of a Barlow and an eyepiece as a new, unique eyepiece, why is it that you can't just focus it as you would any other eyepiece? Jon Well, having spoken to TeleVue about it:The SIPS Paracorr lens is placed in a specific place in the light cone of the telescope. Once that is dialed in, what happens after that, you are correct, doesn't matter, where barlows are concerned.Though it is possible that some older, very long, barlows might protrude hazardously far into the focuser, so long as the barlow doesn't impact the lens, there is no problem with using any barlow with the SIPS.2" Barlows cannot hit the lens, and 1.25" barlows will automatically be pulled back by the 1.25" adapter in the focuser. Drop-In adapters wouldn't be recommended, obviously.It's also possible that certain standard barlow+eyepiece combinations might run out of focuser travel due to inward focuser movement, but this might be true without the SIPS lens, too.Having a barlow that is parfocal with the eyepiece is a convenience, but not required.Jon, your question was spot-on, and a good one. Thanks.
Jeff -----TEC 140, Stellarvue SVR90T, SV115T20 and AT65EDQ refractors,Webster D14, C11 EdgeHD Lunt LS60THa solar scope double stacked with LS60FHaTelevue Pan 41; Ethos 21, 17; Nagler 31T5, 9T6, 7T6, 5T6, 3.5T6; Delos 10, 12, ES25, 14, 9Astro-Physics 900GTO with Rob Miller Tri36M TripodDM-4 Mount-Extension-Tripod w/ Sky CommanderDM-6 Mount-Losmandy Adapter/Extension-Berlebach Planet w/ Argo Navis