C10NGT, Z8, 150 Rumak, XLT 150, C6, C5, SW5 Newt, 4.5 Ball, C102GT, C90, ST80, A70LF; 15x70, 25x100; Burgess BV; Paracorr II; T6 2.5, XO 2.58/5.1, Ethos-SX 3.7, Delos 4.5, TV Plossl 7.4-26, BCO 10, Hutech HC 12.5, Sterling 12.5-25, ES100 14, CZJ H 16/25, CZJ O 16, M5k UWA 24, T5 31, Ultrascopic 35, Titan-II 40; Bino Pairs M5k UWA 6.7, Baader Zoom 8-24, M5k SWA 24, TV Plossl 26, RKE 28.7; Zooms NZ 2-4, NZ 3-6, Leica ASPH 8.9-17.8, Baader 8-24; Baader Zoom Barlow, VIP Barlow
The opinions expressed herein are solely mine as an amateur astronomer hobbyist & consumer. Information herein was correlated from experience, discussions with others, & research from multiple sources freely available at time of posting. All reasonable care & skill was used, but no warranty is made as to accuracy, & liability cannot be accepted for errors/omissions. This is for information only and not intended nor implied to be a substitute for professional advice.
Quote:Ahh... the orographic clouds of Mars!
Quote:John, I wish you hadn't mentioned those MonoCentrics and the barlows, as both are high up on my list of 'most desireable items to acquire.' I am trying hard to exercise restraint and to not blow the budget! I am glad to hear that your experiences with both of those have been great so far, thanks for sharing. It is very tempting to collect more of a series, or a specific make, after a successful purchase has been made. That is partly why I am hedging here, as knowing myself, I will not easily be able to stop at just the purchase of one item from those different lineups of eyepieces and barlows , if I end up being satisfied with the first one I choose here.
17.5" Dob "Beta Version"
NP 127 on a CG-5 and CGEM DX
25x100 and assorted other binos
Naglers, Ethos and various others.
Quote:It was an interesting experiment, just handle the pieces on a tray with raised sides because you will drop something and the soft plastic tweezers hold the lenses better than metal or bamboo. Otherwise ZZIIINNNGGG... where did that lense go?
Quote:Comparison lens Pentax XO 2.5mmRuby- too dark, a double image like misaligned binocs.Saffire- worse than ruby.N-LasF9- almost as good as Pentax.BK-7- about same as laser ball.Fused Silica- Best, same as Pentax.
Quote:Personally I find they have too much scattered light probably due to the lack of anti-reflection coating.
Quote:I would say this is probably due to a less than well polished surface.
Quote:Since a spherical lens is of course strongly curved, and since it is a singlet, there is no issue with ghosting or reflected light bouncing between elements or anyplace that can cause ghosting, further reducing contrast due to this, in addition to the contrast loss from scatter.
Quote:Quote:I would say this is probably due to a less than well polished surface.You know Bill I’m not sure that it’s from the polish or what it’s from. I believe I’m using the same "tech-spec" spheres from Edmunds that you are.All I know is that the Ball eyepieces seem to have sharp focus at their very narrow sweet spot. But I find the contrast of to be a bit washed out.Quote:Since a spherical lens is of course strongly curved, and since it is a singlet, there is no issue with ghosting or reflected light bouncing between elements or anyplace that can cause ghosting, further reducing contrast due to this, in addition to the contrast loss from scatter. Well I wouldn’t say there isn’t any place that can cause ghosting. Remember, at least a couple of us saw ghosting with the lanthanum balls that made them unusable. The housing of the eyepiece even if it is well blackened can still reflect light. And what about within the ball itself?I can speculate on why I see what I see but in the end unless I were to try to systematically eliminate the cause I’m only guessing.
Tak FC100 Tak FS152 10" f/6 Zambuto dob 24" f/3.3 Starstructure