Orion ED80 - AT Voyager with TNT,pier ext.,Vixon steel tray and Manny's mod.
Omni 120 cg4 with Orion pier ext. and RA drive, Binotron-27 (25mm & 17mm Sterlings)
Orion XT10(Original F/5) SkyStopper Equatorial Platform
Jason Constellation Model 311(Modified with 1.25"Crawford Machine focuser & rings)
10" F/4.7 Modified Skywatcher Reflector, 38mm Orion Q70, 17mm Modified Ultima LX, 10mm TeleVue Delos, 7mm Pentax XL.
Quote:Given the $50 price difference between them and the ~10% change in magnification, is there any reason to prefer one over the other in my scope? Does one perform better in a slightly-speedy f/4.9 scope?
14" Strut; 10"XT; 102ES; 22 in Process; 3.5,5,7,10,14,20mm Pentax XW; 17.3 & 12mm Delos; 27mm Panoptic; 20&24mm ES 68; 24mm ES 82; 30mm ES 82; 6&10mm BCO;
“I am the only person to ever ace a 1951 USAF resolution test. My 'to observe' list says 'done'. I do not use charts or atlases when I starhop; men do not use maps. One of my sketches won an SBIG deep sky imaging contest. I am the life of star parties I have never attended. I never say anything looks like a faint fuzzy - not even a faint fuzzy. Pilots aim green laser pointers at me. Don Pensack proofreads my CN forum posts.” - The Most Interesting Astronomer in the Universe
Quote:There is a slight coma in the EP from my Zambuto mirror but if I find that disturbing the Type I Paracorr kills that coma on the edge off.
C10NGT, Z8, 150 Rumak, XLT 150, C6, C5, SW5 Newt, 4.5 Ball, C102GT, C90, ST80, A70LF; 15x70, 25x100; Burgess BV; Paracorr II; T6 2.5, XO 2.58/5.1, Ethos-SX 3.7, Delos 4.5, TV Plossl 7.4-26, BCO 10, Hutech HC 12.5, Sterling 12.5-25, ES100 14, CZJ H 16/25, CZJ O 16, M5k UWA 24, T5 31, Ultrascopic 35, Titan-II 40; Bino Pairs M5k UWA 6.7, Baader Zoom 8-24, M5k SWA 24, TV Plossl 26, RKE 28.7; Zooms NZ 2-4, NZ 3-6, Leica ASPH 8.9-17.8, Baader 8-24; Baader Zoom Barlow, VIP Barlow
Quote:I'd go with the 28mm ES 68 or the 24mm ES 82. Both are smaller and lighter and much less likely to generate balance problems with the scope, and each produces an exit pupil that should be fully usable by any eye even with a fair amount of light pollution. 1.5 degrees of TFOV is *plenty* and the contrast with the slightly smaller exit pupil should be better.Regards,Jim
Teeter STS 11 f/4.3 Zambuto | XT8i | XT8g | XLT 150 | C90 | EON 80mmAT Voyager and Nexstar SLT mountsEyepieces: Mostly TeleVue and PentaxDenk II BV'er, Earthwin PFS-SE, Pentax 10x50 PCF WP II
10" OO VX, 6" iOptron Mak-Cass, Orion 100ED
My eyepieces are made from the waste product of exploding stars. 10XTi 102XLT ST80A(2" Focuser) XW: All; XO: 2.58 Televue: Naglers-T1 Smoothside-full set, 17T4,12T4,Ethos 17,4.7; plossels-40,32,20,17,&7.4mm; Pans-22,24mm; Delos-6,8,12,17.3mm ES100: 5.5,9*,14,20 ES82: full set ES68: 16,20,24,34 NLV: 5,9,10,15 Ortho: HD-7,9; OPS-9,12 Meade RG 7mm Other: Pentax 12.5K(.965), 10mm Parks Zoom: Nag3-6 *=on b/o DAS Dark Site
Quote:One way to solve balance problems in a Dob is to attach a counterweight toward the bottom end underneath the OTA (longitudinal balance) and another smaller counterweight toward the sky end opposite the focuser/finder/Telrad complex (lateral balance). Set up the weights to balance for the heaviest eyepiece you will use. Then if you put a much lighter eyepiece in the focuser, you can compensate for the loss of weight by attaching a magnetic weight or two on the OTA near the focuser. IMO & IME, this makes very good sense because you are putting weight back where you've taken, not somewhere else on the scope.This will work even if your Dob mount - like mine - does not have detention on the altitude bearings. And IME this method is more convenient, more stable and makes more sense mechanically than moving a weight up and down the back of the OTA.Using this method, I can easily balance for my ES 82 30mm or my lightest ortho. It works just as well in my 5" Dob as in my 10".Mike
Quote:Why anybody would want to fuss with something else while putting in / pulling out eyepieces is beyond me. No thanks.
Quote:It's all six of one/half dozen of the other. The bother is more up front in that, once the eypeiece is changed, we're back to viewing without "nudging". That being said, I have no problems with "nudging". While I love my refractor and EQ mount, I'd just hate to think of putting a 10" on an EQ mount---what a monster....talk about a balancing act.....
Quote:Are you talking about a 10" Newt on a GEM? That is the worst of all possible worlds. Tried it once but never agai
Quote:IME, there are a number of problems involved with mounting Newts on GEMs: an 8" or larger Newt on a GEM can be a bear to mount and handle (6" or smaller are OK); the focuser gets itself in precarious positions (rotating rings fix the problem, but are a bother); the focuser is often too high unless the observer stands; the extra weight and cumbersomeness of a GEM makes the scope more of a chore to move and setup; the OTA can hit the legs when pointed toward zenith. A better solution to heat rising from the ground is to only set up on grass and/or put a carpet under the scope.
In general, I prefer a Dob to a three-legged Newt.
I agree about GEM's putting the scope in all kinds of weird positions. This is where the fork mounted CAT comes into play with good positions to the telescope for every kind of orientation in the sky.
I think the fork mounted CAT is the way to go of you want tracking.
Quote:CATs certainly are handy but I believe a Newtonian with top notch optics is capable of providing better views. This is the eyepiece forum so it is probably best that it not drift too much more off topic. I will just say this:
Done right, a big Newtonian on a GEM is difficult to match when it comes to the quality of the view.
Quote:I'd never go the 10" on a stick route. The 4" refractor is enough for slewing around as it is. I have other means to determine wind direction without using a Newt as a windsock.....To each his own though...
Quote:Quote:I'd never go the 10" on a stick route. The 4" refractor is enough for slewing around as it is. I have other means to determine wind direction without using a Newt as a windsock.....To each his own though... I would never put more than a 6" Newt on a GEM, even on a perfectly calm night. That's my preference based on my experience, even before I start to consider the wind factor. But I've observed with my 10" Dob in wind gusts as high as 25 mph. The scope did not move at all. Mike
C14 XLT, CGE NexSTAR 11 GPS + 120ST APM/TMB 130/780, AT111EDT SW EQ5P (2" Tripod/20" Pier) XW's 3.5mm - 20mm, 28mm RG, TVZ 2-4 ES14mm/20mm 100° UWAN 28mm,Paragon 40mm, TV55, Meade 2X 2" TeleXtender TMB SMC 4mm-16mm, Pentax 0-18, CZJ 0-25 EarthWin PFS-DBSE, WO DuraBright, AP MaxBright TV Bino's Bino Sets X 2: UO H.D's ~ 5mm-18mm, TV Pl.(NJ's)7.4mm - 40mm 16T5's, 24mm Pans Canon 18X50 IS Pentax 7X35 (9.3°
Quote: The problem with large fork mounted Cats is that you're OTA is dependent on potentially unreliable electronics...
Quote: Quote: The problem with large fork mounted Cats is that you're OTA is dependent on potentially unreliable electronics... There were three guys with a 12 inch LX-200 GPS that used to share a "secret spot" with my wife and I. I had my 12.5 inch Dob which was pretty reliable, never had any electronics issues... On more than one occasion, they would set up the LX-200, that took quite a while, then I would hear some wild slewing of the motors, some discussion, some more wild slewing of the motors. I would wander over, the controller was giving them an error. They would tear it down.. And they then strolled over my way...Their backup was me... Jon