I wonder, because the set-up instructions of my
Tonight there's full moon, and very little clouds, so I got to (re-)do the setting up. Unlike trying in daytime with treetops half a kilometer away, this time all the eyepieces came to focus. It seems that half a kilometer is not nearly "optical infinity". But, this time the CC'c helical focuser needed to be screwed almost all in. No more extension tubes. Even the 26 mm Omegon SWAN 70° came to focus (that I saw around the huge secondary mirror shadow).
The reason I'm asking how CC works, is if there is an "alternative" way to set it up such that there'd be more room for focusing - or even play for tinkering with afocal photography. Or is there only one correct place where it works as it should? For prime focus photography, the helical focuser can be removed.
At least got enough "light treatment" tonight. (The full moon looked pretty bright through a 300 mm telescope.)
Couldn't do further tests, like with barlow, because it's already late (0:38 AM) and I got to wake up for work.