If you own a Schmidt–Cassegrain telescope and would like to attach a DSLR or MILC camera, you will also need this SC/T2 adapter (50 mm). Screwed onto the rear of the telescope, it provides a connection with a T2 thread, onto which a T2 adapter suitable for your camera type can be fitted.
The ideal backfocus distance is 105 mm for the Celestron f/6.3 focal reducer. For example, with a Canon EOS DSLR/MILC camera, the combined flange focal distance and T2 adapter length is 44 + 11 mm, i.e. 55 mm. Adding the 50 mm length of the SC/T2 adapter gives the ideal total distance of exactly 105 mm. This value may differ for other manufacturers, especially with MILC cameras.
