I had a chance to look through a BTX a couple of weeks ago and today I updated my http://www.pt-ducks....#CR-binoviewing info with a BTX small test and comparing it to my STX as also to my CR-binoview combo. I found some interesting points that no one mentioned until now:
- there are absolutely no ghost images at all!!! My MARK V have these if I look for...;
- there is no polarising effect within both ocular sides;
- within some lowlight conditions the BTX bested my STX! This might be interesting for astro use although others mentioned a small increase of CA compared to the STX, that also shows minor CA - having used extensively my Optolyth 100, I hardly notice any CA on my STX95... The X85 is supposed to be better corrected for CA but I never tested one.
More info and photos at the page.