Hello - I produced this 'super-digiscope' attempt a few years ago - showing that I could resolve a small red flag on Great St Mary's Church adjacent to the iconic King's College Chapel in Cambridge, UK, photographed from the neighbouring county of Hertfordshire. From an OS map, I have measured the distance of the buildings to me as 20,000 metres. Interestingly, photographing the scene at this range gives the impression that the chapel is not nestling amongst the city's numerous buildings!
BTW I resisted changing to an LX7 panasonic as the newer model lost the useful filter thread surrounding the lens housing. The fluorite-crystal 823 kowa scope I use is now ~16 years old but still produces great images despite regular heavy use over the years. I'm not yet convinced I would get much better IQ from the replacement 88 mm model - but its successor could be tempting!
David
Impressive distance David. It's more likely that air quality and time of day would make a bigger difference at that distance than a new scope or camera.
Neil.