I have been testing some eyepieces in the WO Binoviewer

[avtaram]

I have WO Binoviewer which I use in my Evostar 120ed ds pro and Zenithstar ZS71 ed.

The Binoviewer came with a pair of WO 20mm WA eyepieces and I had acquired a pair of 15mm Meade Super Plossls.

I use the Binoviewer mainly for viewing The Moon and these eyepieces give beautiful immersive 3D views of The Moons surface. You get the feeling that you are actually flying over the surface of The Moon, especially if you have a dark towel draped over your head to cut out any extraneous light.

I should add that in order for the Binoviewer to come to focus in both scopes I needed a 1.25" Diagonal and the 1.6X Barlow that came with the Binoviewer had to be placed between the focuser and the Diagonal. This would make the Barlow more like a 2X or possibly a little more.

Even so I wanted a little more magnification and Zoltan at 365 Astronomy very kindly lent me some eyepieces to test so I could choose the pair best suited for my needs.

Magellan WA 12mm :

While this eyepiece produced a clear sharp image there was vignetting in about one third of the FOV. this gave the effect of looking through a tunnel.

To me this was very off putting and there was no sense an immersive 3D effect.

For this reason I thought this would not be suitable for this Binoviewer.

Abbe Ortho 10.5mm :

This eyepiece gave a sharp image with good contrast but vignetting was even more than in the Magellan. Again I found this unsuitable.

Columbus UWA 11mm 80* :

The image was sharp but I was surprised at how much vignetting there was.

Rather than looking through a tunnel it was like looking through a drain pipe.

Not suitable at all.

Celestron Omni Plossl 9mm :

Good sharp image but there was vignetting on about one third of the FOV.

Again not suitable.

Celestron Omni Plossl 12mm :

Again good sharp image but there was still a little vignetting around the edge and for me this was still off putting so I judged it as not suitable.

SkyWatcher Ultra Wide 9mm :

When I first looked through these eyepieces my immediate reaction was a loud WOW.

Good sharp image that covered the full FOV. That immersive 3D image I was looking for was there right in front of me and it was magic.

This eyepiece is definitely suitable for the WO Binoviewer.

Avtar

[brantuk]

That's very useful to know - I might just get a pair of the SW UW 9mm's to try with mine based on what you say - so thanks for that.

To block out light from the sides entering your eyes and reflecting in the eyepieces you can get a pair of Winged Eye Guards. They do them at Sherwoods amongst other places. http://www.sherwoods-photo.com They do help create that immersive flying illusion.

[brantuk]

Well - I've ordered them - actually I've dropped the hint to my missus for a xmas pressie lol

[Mark in Macc]

Thanks for the heads up on these. I might ask to borrow a pair at a longer focal length to try. Suitable EPS for binos are not 2 a penny.