In addition, on the right side, there is a small opening about 15 ° at the bottom of the right eyepiece tube. A little external light penetrates into the right tube. Is that also normal?
Iy fou are talking about the whole close to the bridge, which is closed when you move both parts of the binoviewer to the closest pupil distance: This is normal and necessary to adjust the interpupillar distance; but intruding light is no problem.
It happens "in the brain" that both light trains become reunified. And what actually happens there is that the image all of a sudden does NOT look dimmer but that fine detail and most subtle color differences within planetary surfaces become recognizable much easier and that observation happens effortlessly without fatigue - even when observing over a long time. Regardless of light throughput - the real virtue of a binocular viewer does lie in the optical quality of the glass and utmost care in optical surface polish, in perfect angle orthogonality of each prism, an immaculate beam splitter quality, highest degree of optical adjustment of all optical elements at any interpupillary distance - and only lastly: utmost coating quality. These are the most necessary criteria (in this order) for supporting an undeteriorated viewing experience with both eyes - even at highest magnification work. So - whatever anyone else is claiming - the Mark V has the best light throughput and the highest quality prism surfaces and adjustment - and and and - of any commercial astro-binocular viewer in the market.
I am using a Takahashi 120 refractor (TSA-120) F/7.5. Would Glasspathcorrector Factor 2,6 be a good choice?
Also, I like to ask you for what Diagonal to chose for this Bino. I have the Baader 2" ClickLock Diagonal Mirror # 2956100, for a year and I am very, very pleased with it!!
Should I choose this diagonal # 2956100, or should I chose Baader 2" ClickLock Diagonal Mirror M68 thread (Zeiss) # 2956100Z for the Mark V Großfeld (Giant)-Binocular with Glasspathcorrector Factor 2,6 ?
To attach the Hyperion Zoom, we recommend to use the adapter "A" for spotting scopes which is included with the eyepiece, because it saves you some more millimetres of backfocus.
Respectively for the 1,25" ClickLock see this Item:
Manufacturer Baader Planetarium SKU (#) 2456410 EAN Code 4047825010971 Weight (kg) 0.795
You may also be interested in the following product(s)
As low as: € 425.00
€ 215.00 Price excl. German VAT tax (19%): € 180.67
€ 99.00 Price excl. German VAT tax (19%): € 83.19
€ 180.00 Price excl. German VAT tax (19%): € 151.26
€ 92.00 Price excl. German VAT tax (19%): € 77.31
€ 96.00 Price excl. German VAT tax (19%): € 80.67