How to use 1.25" (31.7mm) filters in a T-adapter.
Note: Eyepiece holder has been disassembled and reverse mounted.
Remove locking screw (if too long to fit into telescope draw-tube) on T-adapter.
(To hold barrel in place use a piece of plastic, or glue in place.)
T-adapter now fitted into camera T-mount adaptor.
Filters can be fitted into the (hidden) Barlow barrel.