I have found on my Orion 10" Dob that i had to move the primary mirror 1 inch closer
to the secondary to be able to focus with my Canon 350D no matter what adapter i used.
Not enough in focus.
All works good now. Just that i now need to add a extension for visual.
You may want to look into a low profile focuser to get more in focus if i read you
orginal post correctly.
It may be something like that. I'll park this suggestion as I may need to come back to it once I exhaust all options. Thanks for commenting.
I have found on my Orion 10" Dob that i had to move the primary mirror 1 inch closer
to the secondary to be able to focus with my Canon 350D no matter what adapter i used.
Not enough in focus.
All works good now. Just that i now need to add a extension for visual.
You may want to look into a low profile focuser to get more in focus if i read you
orginal post correctly.
I replaced the stock focuser on my C8NGT with a low profile focuser for this very reason. Also the fine focusing I can now get with the 10:1 fine focuser really makes focusing so much easier. As mentioned above I also had to purchase an extension tube to continue using my eyepieces.
  