I have been thinking of buying two Vixen 39208 NPL 30mm Telescope Eyepieces for my Williams Optics Binoviewer. I kind of think these 4- element PLOSSL series eyepieces are about as large as a 1.25 barrel will allow.
My reasoning has two objectives, 1) widest possible views, and 2) with many of my optical systems, I have to barlow with an Orion shorty 2x (with body removed) to bring about focus. When I am forced to use a barlow, I don't want all that magnification.
Yesterday I took my Lunt LS60T Ha B1200 out and looked at the Sun. Since Eddgie said somewhere that the B1200 allowed him enough backfocus to use his bino, I tried my more primitive WO. First without any barlow, and that didn't work, so I tried the 1.6 that comes with the WO binoviewer package. That didn't work, but it almost did, it just ran out of adjustment back space. I almost gave up and was about to order a WO 2x barlow that screws into the nose piece, when I remembered a bag of odd optics that came with my used Vixen (Orion) R200SS. In there was an Orion Shorty 2x and I remember reading that it can be taken apart. The optics screwed into the nosepiece and I had plenty of backspace. (loved showing my wife what the sun looked like with two eyes!)
Looking at the sun with two 20mm lens was almost too big, the sun just barely fit into full view. It felt like a 9 mm in mono view, a bit too close for my manual tracking with a Vixen 3992mini Mini Porta Mount. Every two minutes I had to re-center the sun.
I suspect 30mm will work OK for solar observation, because there is lots of light, and a little distortion around the edges may not be a distraction. But I want to do a variety of sky viewing. I want to buy a Vixen 2604 R130Sf Telescope, because it seems to be the ideal grab and go telescope. I also suspect that a binoviewer will work If I connect in with a T-2 adapter. It seems that the Vixen R200SS and smaller R130Sf both allow T-2 threads half way off the focuser and before the eyepiece. This backfocus was to allow camera connections, but it seems to me to also allow a binoviewer to fit nicely into the optical path. Why not try to have two eyes on the sky?
Having fallen in love with astronomy, I want to have several choices in equipment. I have the 'big aperture' covered with a 17.5 inch F6 dob, and a NS11 GPS. (just bought a Hyperstar III so in a few weeks M11 will be my focus). I also put the R200SS on a Celestron Cg-5, which leaves an unused GP2 mount. That will nicely hold a R130Sf. My hope is to have appropriate equipment to quickly get some sky viewing time in. Even better if I can use both eyes.
(M11 is my current favorite using the C-11 and WO bino raw. My next favorite is mono viewing with a 2 inch 16mm 100 degree Zhumell) (With my 17.5 inch F6 Dob my favorite is M5, but It is hard for me to find.)
I have been reading these binoviewer posts and no one talks about the little Vixen 30mm eyepiece. Is there something I am missing? My hope is that it will work well for the money spent. Has any one tried using these in a binoviewer, and did they have any success?