Antares 1.6x 2" barlow for binoviewing

[esculapius1975]

Has anybody used this barlow for binoviewing (microscope derived zeiss binoviewer). I need to extract the focal plane of a 12" dobsonian to get in focus with a binoviewer. How many centimeters this barlow gains? Will a 2x or 2.5x barlow be more forgiving trying to focus with the binoviewer or should this be just fine?

[Louis D]

Focal length matters more than stated magnifying power because you'll be adding 100mm or more distance between the eyepiece and the barlow element unless the barlow optics element can be directly attached to the nose of the binoviewer.  That 1.6x is fairly short as I recall, so it will still boost power quite a bit because you're adding that extra separation distance.

[John]

The current Antares 1.6x barlow has the same optics but positioned differently within the body to allow for the 2" filter thread and the twist lock 2" barrel. I had one of the new ones a while back and found that I could not bring eyepieces to focus with it in any of my scopes whereas the original design, which I owned a year or so before, worked fine 

I got a refund from the retailer on the 2nd unit and they admitted that they had quite a few returned for the same reason.