It's why Tak yanked the Sky 90 - poor CA control, excessive field curvature, POOR seller due to the abundance of negative feedback.
Having said that though, the Sky90 tests quite acceptably in the CRAP....errr...Strehl tests, but it is still considered the poorest performing Takahashi ever made.
Brian N, the NG I had was as poor as Wolfgang showed - I have often complained of excessive star bloat, star halo (VERY poorly controlled blue), and I am certainly NOT the only one. Some love them, but every single image I have seen published from an NG127 shows a lot of blue halo (due to the scatter in the lenses and the figure). ES's version is BETTER, but they insist on rigid QC standards.
Brian from Mandurah - please also note that the claim that your telescope's focuser (the UO 115) was made and designed in the USA has now been removed from the advertising, and now states the focuser are UO/Kunming made and designed. Be careful out there reporting things, especially when the facts change, NOT in your favour either.
I replied a lot more previously, but the mods saw to delete them all (yet the sleight against AEC remains???), so some will now seem out of context.
Vituttaa,
Lewis