I have a BT-202 and use it for imaging with a Canon 400D fitted with a MPCC (Coma Corrector) - eg
M20
In order to achieve focus with the DSLR I had to move the mirror up the tube towards the secondary. Sounds complicated, but is actually dead easy. I simply replaced the M6 collimation screws and springs with longer ones from Bunnings.
see
here for details. Cost ~ $10-20, time required ~ 15mins, and totally reversible if you want to go back to the original setup