I have been visually observing for years using 8 and 10 inch SCTs. Some "astrophotography" by simply mounting DSLRs on the OTA, nothing through the eyepiece.
I was considering purchase of an ED 127mm triplet for astrophotography.
I have seen some comments in these forums to the effect that experienced Astrophotographers recommend an 80mm or 102mm Triplet refractor scope over a larger version, say 127mm. I infer from those comments that the distinction is somehow related to the sophistication of the 127mm making it not a good fit for beginning or intermediate astrophotographers. Can anyone explain?