Cheers! Its not really the hard,you just get a camera body cap, a lens cap and a piece of pvc tubing around 5cm long.cut a hole in each of the caps so the tube fits tightly inside and then glue them in place.its best if you line the inside of the tube with black felt or card to stop light leaking/bouncing inside and wrap the joins in black tape.it works be if you use a manual focus lens that has manual aperture control.