Posted 26 August 2013 - 11:36 AM
When talking with Celestron about using their new off-axis guider (not the Orion StarShoot OAG, which may have different spacing requirements), with their various EdgeHD reducers, Celestron acknowledged that the one combination that does not work out of the box with their OAG would be the EdgeHD 800 +0.7x Reducer + DSLR. None of the adapters included with the OAG add up to the exact 105mm back focus distance required. Celestron feels there should be enough space to use their OAG (but no guarantees with the Orion) if a low profile 2” SCT back is used with a 2” to T-thread nosepiece instead of the long Celestron 8” EdgeHD T-adapter. The Edge T-adapter has to be long enough to accommodate the focus and mirror lock clutch knobs when used without the reducer, but that makes it too long to fit an OAG into the light path.
Celestron will be adding a knowledge base article to their site about this.