Telescopes: Celestron 14" SCT..Meade 10" ACF/SCT..Stellarvue 4" ED APO Mounts: UA UniStar Deluxe duel clamping saddle on a Celestron CGE tripod...UA UniStar Deluxe on a Meade field tripod and a UA UniStar Light on a UA light surveyor tripod. All with custom made "Manny Miles" eyepiece trays. Binoculars: Garrett Optical 10x50 Oberwerk 15x60. Eyepieces: TV Naglers, and Plossl's. Also Pentax 20XW, a Baader 31 Aspheric and a TMB 40 Paragon.
Quote:Thanks for the information. Do you know of any prism diagonals that come in the 2" size? Seems all the ones I see for sale are 1.25" models. Would like to try a 2" model in my larger SCT. Take care.Bill
Quote:Sadly, most consumers are focused only on reflectivity numbers rather than quality.
Quote:On axis, color correction should be slightly improved but I also agree with Don that there are certain limitations the prism has at faster focal ratios. Perhaps you are both discussing a trade off since you and Don have slightly different thoughts here, and perhaps if you were to use a 2" prism, more of the false color may be seen around the periphery with wider angle eyepieces.
WO Megrez 120 ED on GP Mount
WO ZenithStar 80 ED II on Porta II
10" Meade LightBridge/Paracorr
Orion ED 100 on Polaris Mount
Astro-Tech 8" f6 Dob
Bushnell Ares 5
Meade 226 2.4" f11.7
SpaceScope 2.4" f15
Quote:One problem I have with my cheap 1.25 prism is the sloppy fit in the eyepiece holder. On my Celestron, it is so bad that when the setscrew is tightened it mis-aligns the eyepiece causing distortions that are clearly seen. Does anyone make a 1.25 prism diagonal with a compression ring?
Quote:Clive, that's a good idea. I may just set something up like that.
Quote: a good prisms IMO, is unrivaled. This of course, will depend on certain optical perimeters of the telescope. The prism is the clear winner.
Quote:Baader ofers a "Precision Amici Star Diagonal" is that better than the "click lock 2" diagonal"(or other hi end 2" mirror) for lunar and planetary details?
Quote:Quote: a good prisms IMO, is unrivaled. This of course, will depend on certain optical perimeters of the telescope. The prism is the clear winner.
in what kind of telescope does the prism is superior?
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:One advantage of a 90 degree prism diagonal over a mirror diagonal, is that the prism can deliver a right-side-up correct-right-to-left image, the same orientation that you see naked-eye and on star charts. You don't have to deal with the unnatural, contra-intuitive, reversed orientation. That is a huge credit in my ledgerbook.
I usually insert a 90 degree prism diagonal in my refractors , unless I want to use 2" eyepieces in my ST80 or C4-R. Then I resort to a 2" dielectric diagonal. (Great for Rich Field views of the Veil and suchlike.) If I could afford a 2" prism diagonal, I would get one.
I imagine, though, that a 2" prism diagonal and a big 2" eyepiece would be quite a heavy load for my ST80.
I almost always use the 1.25" prism diagonal in my 6" Mak. It makes Lunar observing with the Rukl atlas much, much easier.
Quote:One advantage of a 90 degree prism diagonal over a mirror diagonal, is that the prism can deliver a right-side-up correct-right-to-left image, the same orientation that you see naked-eye and on star charts.
Quote: I myself, normally do not use dielectric coated diagonals and have always preferred a high quality, aluminized diagonal regardless, but a good prisms IMO, is unrivaled. This of course, will depend on certain optical perimeters of the telescope. The prism is the clear winner.
Quote:Baader, Takahashi, HuTech, Carl Zeiss. Not really sure about that last one--it will depend on the attached adapter.
--------------------Clear Skies, PJ Refl.- 203/1420; Refr.- 110/616, 75/500; Bino.- 15X60, 10X50, 8X30 __________________________________________________
Happy owner of--
A Mag 1, 12.5 inch Porta Ball
A Dual Axis Equatorial Platform
A PST Double Stack