I like were this discussion is going. Hand figured doublets and triplets come at premium. Most of us are looking at mass-produced scopes in particular in larger aperture
At one point I had a choice between similarly priced ES
triplet and SW
120mm ED doublet. My understanding is that the larger scope gets the harder is to get the same level of CA
correction in a doublet compared to triplet. So, I went with ES
, because it was triplet, had larger aperture
(hey, every mm counts!
) and I knew that I can rely on ES
customer service if there will be any issues.
I was very happy with ES
127mm performance. I don't believe I saw as sharply defined airy disks in my other fracs which all happened to be doublets. It could be just seeing, I did not do comparison on the same night, also the aperture
sizes are different. But we are talking about cumulative experience based on multiple sessions. At one point I had ES
102mm triplet and now have Stellarvue 102mm doublet. I don't believe I ever saw Jupiter as sharply defined in SV
compared to ES
, but the color saturation seems better in SV
(the colors could be because of upgraded diagonal). Again apples to oranges, different nights. Maybe higher position of Jupiter.
I did not think of it much until I read Jones comments, which seem to match my experience.
Scopes: Stellarvue: SV102 ED F7; Celestron: 9.25" EdgeHD F10, 8" SCT F10, Omni XLT 150R Achro F5, Onyx 80ED F6.3; Meade: 80ST Achro F5.
Mounts: ES: Twilight I; Bresser: EXOS2; SW: SkyTee2, AzGTi; UA: MicroStar.
Binos: Orion: Binoviewers, Little Giant II 15x70, WorldView 10x50, Nikon: Action EX 16x50 & 8x40.
EPs: Pentax: XWs & 2xXFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: 2xBCOs, Aspherics, Mark IV, Meade: Plossls.
Diagonals: Baader: BBHS silver mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: Positive lock prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC, Orion: UltraBlock, SkyGlow.
Observing: DSOs: 2246 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 1770, S110: 77). Doubles: 1448, Comets: 18, Asteroids: 97