I started my first observation during daytime, using 10mm Vixen SSW eyepieces (50x).
Immediate irritation: AOK had supposedly aligned the two tubes before I got them, and I had anticipated that I had to just fine-tune alignment using the two knobs on the EMS, but there was not enough left-right / up-down travel on those. So I had to first roughly re-align the tubes again. This turned out to be much easier than expected. The manual downloaded from AOK’s website indicated 4 screws on the side of and below the mounting platform, two of which work in “push” and two in “pull” function, allowing alignment of the tubes horizontally and vertically. It took me about 5 minutes to perform the entire procedure, including searching for the right size screwdrivers (I remembered only later that AOH had actually provided me all the necessary tools, which I had already stored), and I did not even have to dismount the Borg from the tripod.
Then back to observing. I chose a street sign 1.2miles away to focus for both eyes, then fine-tuned the alignment with the two knobs on the right-hand EMS, first vertically, then horizontally, as recommended by AOK. Checking the result by taking my eyes off the eyepieces, waiting for a few seconds, then looking through the eyepieces again – perfectly aligned! Sharp and bright image, as hoped for.
Later that evening, first light on a partly cloudy sky observing Venus at 9:30 pm, using 7mm DeLite eps (71x). Conditions were not great, but I got an outstandingly clear and crisp image of crescent Venus in the Borg. For comparison, I put the Borg side-by-side with the Oberwerk 100XL ED (9mm Nagler eps, 62x). Venus stood already relatively low, and the air turbulence impacted the image quite a bit, more so in the Oberwerk than in the Borg, which I found surprising, I would have guessed the opposite, due to the higher magnification of the Borg. The Oberwerk showed just slightly more color than the Borg (which didn’t show any), not too bad, but noticeable. Also, due to Venus’ brightness, there was a tiny bit of a “halo” around the planet’s image in the Oberwerk, which was totally absent in the Borg.
On May 20 at 9:20 pm, the sky was clear, and this time, I compared the Borg side-by-side with the Kowa Highlander. I used 9mm Kowa eyepieces, of which for some odd reason I happen to have two pairs, in both instruments (note: while you can only use Kowa’s own eyepieces in the Highlander, the Borg, like many other binoscopes - e.g. Vixen or APM – works well with Kowa eyepieces). The 9mm Kowa eps give 50x magnification in the Highlander and 55x in the Borg. I found the image very comparable in both instruments, nice sharp image with no color fringes in either; the Borg with its larger aperture was a bit brighter, despite the slightly higher magnification.
Learning from that evening: after a change of eyepieces, you may have to fine-tune the conditional alignment on the Borg. Since this is effected by using the two knobs placed at the right-hand EMS, it takes 5 seconds and is no issue at all (concerns in some threads that this might be complicated and / or time consuming are totally unfounded), it is actually easier and provides better results than the adjustments I have to perform on the eps holders of my APMs or Obies after changing eyepieces).
May 24 afternoon: daytime observation of various targets, comparing the Borg (Nagler 9mm, 55x) with the Swaro BTX (60x95). The image in the Borg was clearly brighter – no surprise -, sharpness** better in the Borg, contrast** however about the same, which shows that brightness alone is not “always everything”.
** I am using the terms sharpness and contrast here “literally”:
Sharpness = how small is the transition area between light and dark in the image
Contrast = how strong is the difference between light and dark sections in the image
May 26 early evening: observing the 4 day old crescent moon with the Borg (9mm Nagler, 55x), the Kowa Highlander (9mm, 50x) and Oberwerk 100 (9mm Kowa, 62x). No color fringes in the Borg and the Highlander, very little in the Oberwerk. Detail recognition is best in the Borg, second Highlander, last Oberwerk (the latter also exhibited difficulties in achieving a fully aligned image, I had to re-insert and rotate the eps several times and I also switched with the eyepieces from the Borg until I got satisfactory alignment of the images in the two tubes. My sample of the 100XL Obie is unfortunately more prone to double images than my 82XL).