For my binoviewer setup, something in the 20-21 focal length range would end up being my "high power" eyepiece, which would present approximately 400-500x in my scope. Nights that I can use that magnification are rare, but the past few observing sessions would have benefitted from that kind of magnification.
Given the stock issues with the 20mm TV Plossls, I've also be considering the 21 Edmund RKEs.
Has anyone done any comparisons between the two either mono or binoviewing?
(note that anything below 20mm is just too much magnification for my setup, else I'd be looking at some 18 abbe Orthos or 18.2 DeLites. Above this I have a pair of 25mm Zeiss E-PLs that I love).
the 21mm RKEs are certainly a very good choice, and not breaking the bank.
The f=20mm eyepieces are in my current arsenal underrepresented,
the best one is the Leica HC 12,5x/16 Plan M #506515, f=20mm, AFOV 45°,
with its lenses sequence (1 - field stop - 2 - 1 - 1) concave concave out, a bit oversophisticated. With its intrafocal design and internal focusing (M) on the field stop, I can play to get the best performance across the field, whenever I have "Lust" to do it. The field stop is not fringing.
I have also the Carl Zeiss S-Pl 12,5x/16 #44 40 49 f=20mm, but somehow my eyes prefer the Leica.
The third one is the old Swarovski 22x Habicht f=20.9mm AFOV 55°, not bad either, but the adapters to 1.25" are as good as unavailable.
Wishing you the best choice,
Edited by j.gardavsky, 24 September 2021 - 10:08 AM.