Camera-microscope adapter for less than $15

Step 3 Cut and glue foam.

Cut (using hot wire) the foam to make a ring (like the one on the photo). The outside of the ring should be of the same diameter as the PVC pipe, the inside of the ring should be slightly (about 0.5cm / 1/5") smaller than the eye piece of the microscope that you will use (so you need to measure the eye pieces before you start).

Once you've got your ring, apply a small amount of crazy glue to one edge of the PVC pipe and glue it to the foam while applying pressure.