I know this is a long thread. probably read 1/2 of it all.
Just received my Orion CC8. I am setting this up for planetary Photography with a ASI462Mc camera.
I was finally able to achieve focus using all three extensions (4") and racking the focuser out to 45mm of the 50mm travel. The was NO barlow or diagonal used.
This just does not seem right to me, I took a not so good picture of my secondary.
Will measure later today but I would say the gap is closer to 5mm where you can see the threads.
I am not sure exactly what screws to loosen so I can screw in the lock ring to bring my focus in with out so many spacers.
Brand new scope from Orion, have actually thought about just sending it back.
If I read and understand all this correctly my mirrors may be too close to each other.
If this CC8 photo helps…I have collimated the scope, but never changed the secondary spacing. This is what it’s been since shipped from Orion. If you zoom in you can count the screw threads.