Come join the friendliest, most engaging and inclusive astronomy forum geared for beginners and advanced telescope users, astrophotography devotees, plus check out our "Astro" goods vendors.
Come join the friendliest, most engaging and inclusive astronomy forum geared for beginners and advanced telescope users, astrophotography devotees, plus check out our "Astro" goods vendors.
An easily recognizable difference in the lens form and groupings can be seen on the 40mm and 30mm XW eyepieces.
The last group in the old XW 40mm includes three lenses, with its first lens flat out, followed by a double concave lens, and finally by a biconvex eye lens.
In the new XW40-R version, the last two lenses are cemented into the eye doublet.
The last group in the old XW30 includes again three lenses, with its first lens flat out, followed by a double concave lens, and finally by what's looking like a meniscus eye lens convex out.
In the new XW30-R version, the last group begins with a cemented doublet, followed by a meniscus eye lens.
Herewith the new XW40-R and XW30-R are replacing two lenses with a doublet, and flip this doublet for the both focus lengths.
These differences may be due to the economic availability of the special glass materials, as this economic availability changes with time.
During one of the last shoppings at Intercon Spacetec, I have added the old SMC Pentax XW-30 to my arsenal as a luxury wide field star-hopping eyepiece. The most difficult nebulae will be still observed within the small AFOV (45°) Leica L Plan 32mm eyepiece, having just 4 thin lenses inside for the maximum light throughput and contrast.
Thank you for reading,
JG
6" F/5 Sky-Watcher achro, 2" BBHS Star Diagonal, 2" zenith prism, 1.25" Takahashi prism Leica 82mm APO Televid Eyepieces: Docter UWA; Leica B WW and WW Asph. Zoom; Leica HC Plan S and L, monocentric; Pentax SMC XW, O-, XO; Tak MC O, Carl Zeiss B WW, and Pl, E-Pl, S-Pl, W-Pl;
Swarovski SW; Baader Symmetric Diascope Edition; Nikon NAV SW, ; TMB supermonocentric; Rodenstock; Vixen HR; TV Delos Filters: Astrodon, Astronomik, Baader, Balzers, Zeiss West and East, Lumicon Binoculars (7x42 up to 15x85): Docter Nobilem, Leica Ultravid, Nikon Astroluxe, Swarovski EL Swarovision; BA8 (Kunming Optical)
Thank you for the report JG.
Interesting that with the new glasses available they were able to eliminate a lens in the design.
Gabrielle See Far Sticks: Elita 103/1575, AOM FLT 105/1000, Bresser 127/1200 BV, Nočný stopár 152/1200, Vyrobené doma 70/700, Stellarvue NHNG DX 80/552, TAL RS 100/1000, Vixen SD115s/885 EQ: TAL MT-1, Vixen SXP, SXP2, AXJ, AXD Az/Alt: AYO Digi II, Stellarvue M2C, Argo Navis encoders on both Tripods: Berlebach Planet (2), Uni 28 Astro, Report 372, TAL factory maple, Vixen ASG-CB90, Vixen AXD-TR102 Diagonals: Astro-Physics, Baader Amici, Baader Herschel, iStar Blue, Stellarvue DX, Tak prism, TAL, Vixen Eyepieces: Antares to Zeiss (1011110) The only culture I have is from yogurt
Lady Fraktor wrote: ↑Mon Apr 19, 2021 4:11 pm
Thank you for the report JG.
Interesting that with the new glasses available they were able to eliminate a lens in the design.
Hello Gabby,
bonding two lenses together, they have eliminated just 1 air gap, not a lens.
Best,
JG
6" F/5 Sky-Watcher achro, 2" BBHS Star Diagonal, 2" zenith prism, 1.25" Takahashi prism Leica 82mm APO Televid Eyepieces: Docter UWA; Leica B WW and WW Asph. Zoom; Leica HC Plan S and L, monocentric; Pentax SMC XW, O-, XO; Tak MC O, Carl Zeiss B WW, and Pl, E-Pl, S-Pl, W-Pl;
Swarovski SW; Baader Symmetric Diascope Edition; Nikon NAV SW, ; TMB supermonocentric; Rodenstock; Vixen HR; TV Delos Filters: Astrodon, Astronomik, Baader, Balzers, Zeiss West and East, Lumicon Binoculars (7x42 up to 15x85): Docter Nobilem, Leica Ultravid, Nikon Astroluxe, Swarovski EL Swarovision; BA8 (Kunming Optical)
)