I'm shopping for my second and backyard scope, and currently looking at the new TS 150mm f/8 doublet and the APM 140mm f/7 doublet. Looks like they both have FPL-53 glass and similar weight, but the APM is easier to purchase in the US and seems shorter. Wondering if the 10mm or mechanical qualities would make any difference? How much better are they compared to a 115mm triplet?
I'm happy with my first scope, an AT115EDT, which I hauled around mainly for DSO imaging with QHY 294M and Sony a7 FF OSCs, but occasionally also visual and planetary. Since I got a proper backyard and some more budget, I've been thinking about complimenting the 115mm with something more powerful as a wide/deep imaging or imaging/visual combo. However it would still be great if they can ride on my current CEM40 since better mounts like CEM70 are much more expensive and heavier. Also considering reflectors like EdgeHD, but I like the simplicity of refractors, and feel that the 8" is not as good as the large refractors due to CO and image circle (but does looks like a cost effective option for small objects), 9.25" is also too long for DSOs even with FF, and Maksutov-Newtonians seem quite heavy.
Edited by 5th Gin, 26 July 2021 - 01:26 AM.