I feel like this is going to be a duplicate of this question, Astrophotography - Unable to achieve focus with current setup.
However, the suggestions to go to a straight adapter doesn't apply in my case. I have a Canon Rebel XT, with a 2" 48mm adapter https://www.amazon.com/gp/product/B00T3P5ABC/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1, on my Orion XT10 dob, http://www.telescope.com/Telescopes/Dobsonian-Telescopes/IntelliScope-Dobsonians/Orion-SkyQuest-XT10i-IntelliScope-Dobsonian-Telescope/pc/1/c/12/sc/27/p/102013.uts.
When I attach the adapter to the camera and focus on a planet or star, I can't achieve focus. My focus adjuster on the scope can't get close enough. It's as if the camera is just out of range of the focuser.
I'm not sure what the issue is and would love to hear some suggestions. I'm just a noob getting started and have a lot to learn so I apologize at all the beginner questions here.