This “Review of Various Eyepieces for a Binoviewer” has been kindly written by one of our customers who needed a pair of eyepieces for his binoviewer, but wanted to try them before his final decision.

William Optics Binoviewer

We agreed to supply the eyepieces and in return he has written an unbiased review of some of our eyepieces.  We only added the links, images and few notes as you will see… So, here it goes:

Various Eyepieces from 365Astronomy for a Binoviewer

Reviewed eyepieces:
William Optics SWAN 15mm Eyepiece
Magellan Wide Angle 12mm Eyepiece
Magellan Wide Angle 17mm Eyepiece
Skywatcher Extra Flat Wide-angle 16mm Eyepiece
Columbus UWA 16mm Eyepiece
Columbus UWA 11mm Eyepiece

Had some eyepieces to review with a need to buy a higher magnification pair to use with my William Optics bino-viewer attached to a 5 inch Konus refractor F7. At the moment I`m very pleased with stunning images I`m getting with the William Optics 20mm WA eyepieces that came with the bino-viewer, (these look similar to the “Magellan” WA eyepieces offered by 365 Astronomy) and for low power, I use a pair of EF 27mm eyepieces (similar to the Skywatcher extra flat offered by 365 Astronomy). Both of these eyepieces give me what I want, a sharp focus across the whole bright image and a nice black sharp edge to the field of view, together with ease of use… i.e. no kidney beaning and decent eye relief.

I use the scope a lot for terrestrial viewing and a little on the Moon and planets, and enjoy nothing better than to show the uninitiated just what beautiful images a basic scope can give when set up properly, and in particular with bino-vision, especially after they`ve been looking through a flimsy keyhole of a scope that many people buy as a first scope.

SkyWatcher ExtraFlat Wide-Angle 16mm 1.25-inch Eyepiece

So, for my third pair of eyepieces I want something a step more powerful than above, but with similar qualities. The William Optics SWAN 15mm from 365Astronomy was a very good all-rounder, and a neat and professional look to it. It gave one of the sharpest images and large FOV (field of view. The editor). Against was its minimum eye relief to see the full field of 72 degrees, and a bit too expensive for me especially as needed two for my bino-viewer.

I really liked the look of the next eyepiece, the Skywatcher ExtraFlat Wide-angle 16mm, it was a better price for me and a pleasure to use, with its extra eye relief, a great all round eyepiece with flat field and sharp edge to the 60 degree FOV, but you must use the extendable eye cup to ensure the eye keeps good central position and distance. (a perfect eyepiece for spectacle wearers).

11mm Columbus UWA Ultra Wide Angle Eyepiece with 80 degree field of view

Next up were two less expensive eyepieces, the Magellan WA 17mm with 65 degree FOV and the Columbus UWA 16mm with a whacking 80 degrees. Magellan being similar styling to the Williams Swan, and the Columbus a longer tubed style (Plossl ?). Both eyepieces fared well in all areas, the Magellan being equal to the WO SWAN in sharpness, but lacking a very little in contrast, it also had a little more eye relief than the Swan. (These differences might be due to the difference in focal lengths. The editor).

The Columbus also was very good for sharpness and flatness and contrast,  together with the very large FOV of 80 degrees, but of course you do pay for this extra large FOV by a bit more focus drop off at extremities of field, which is only to be expected with 80 degrees! You must keep your eye close to lens to see the full 80 degrees.

From the eyepieces above I personally would have chosen the Skywatcher EF16 to suit me best, I particularly liked the eye relief, which made it very pleasant to use, and no real negatives, but, I`d now decided I needed a bigger jump in magnification than the 16mm range would give me, I therefore checked out the Columbus UWA 11mm 80 degrees, and the Magellan WA 12mm 60 degrees. Both had similar qualities to their longer focused stablemates above, but I did notice that the Columbus gave a blacker sky around the moon than all the others and also its magnification was more like a 9mm eyepiece than an 11mm ?

My personal choice in the end was the Magellan WA 12mm 60 degrees, which gave me slightly better eye relief, the jump in magnification I was after, a clear and very discernible black edge to the FOV, and a very sharp image, even after trying it with my Williams 1.6 X Barlow. With my set-up now, I can pick out the undulations on the sides of the moon`s craters walls, or I can see the hairs on a fly’s leg at 15 yards, all in bino-vision. I`m happy.

Tom Daly

 Edited by Zoltan Trenovszki
www.365astronomy.com