Antares BinoViewer i (pre-owned)

Used, in great condition

Antares BinoViewer (pre-owned)

In many cases, the Binocular Viewer is a clear step ahead of observing through a telescope's single eyepiece. By using both eyes simultaneously to observe, you see up to 40 percent more detail than you do when using only one eye to squint through an ordinary single eyepiece diagonal. Lunar and planetary details snap into focus with a clarity that makes these objects seem almost three-dimensional. Deep space objects, such as globular clusters, take on a solidity and seeming depth that renders them almost three-dimensional, as well. Of course, you're not actually seeing a true three-dimensional image (you are looking through your telescope's single objective lens, after all). However, the human brain is hardwired to assume that two eyes give you a stereo image, so binocular viewing gives many people the illusion of three dimensions. Whether it's true three-dimensions or not, binoviewing is more detailed and aesthetically more pleasing than single-eye viewing.

It is solidly built, with many nice touches you'll appreciate. Rubberized black paint coats the dimpled body to give you a sure grip on cold, dewy nights. Its fully multicoated BaK-4 prisms give you high light transmission. There is no vignetting or light cutoff at the edges of the field such as you get with lesser quality BK7 prisms. The thumbscrews holding the eyepieces are metal, not flimsy nylon or plastic that can be affected by cold weather.

The 1.25" adapter tube is threaded for filters, which comes in handy if you decide to use a contrast-enhancing filter or neutral density (Moon) filter for long planetary or lunar viewing sessions. 

The Stereo Binocular Viewer can be used as-is with any catadioptric telescope using 1.25" accessories, as Schmidt- and Maksutov-Cassegrains typically have enough back focus to accommodate the extra light path of the prisms in the Binocular Viewer. Achieving focus with a refractor or reflector having limited available back focus might be a problem, however. Some refractors and reflectors have removable focuser drawtube sections for astrophotography. Removing the drawtube section will usually provide enough additional in-focus to use the Binocular Viewer. For those refractors and reflectors that do not have enough available back focus, a 2x Barlow placed in front of the Stereo Binocular Viewer will act as a transfer lens and usually allow the Binocular Viewer to reach focus. Any brand of physically short Barlow will usually work quite well.