"Bargain Home-Made Wide-Field Eyepieces" - Richmond Windsor, (HAA)

Hawkesbury Society member Richmond Windsor, has been experimenting in amateur construction of wide field eyepieces. Richmond demonstrated his prototype 25mm eyepiece at a recent field night at Crago Observatory. The eyepiece was made at a total cost of 75 cents, plus labour, and gives an impressive 105° apparent field of view.

His method involves careful grinding and polishing of the bases of eleven jars, which formerly contained pickles and onions. Years of experimentation demonstrated that if the right combination of brand names was arranged in the correct sequence, minimum figuring and polishing was required.

Rough grinding was accomplished using a Ryobi Angle Grinder, while fine grinding was done using a small concrete mixer full of carefully screened Hawkesbury River sand.

The lenses were then polished using a domestic floor polisher and iron oxide fine ground using a coffee grinder. They were then inexpensively araldited in proper sequence using an empty beer can, so that Richmond's focuser had to be fitted with a special adaptor.

Field tests were encouraging. The eyepiece brilliantly displays all the colours of the moon, and many hitherto unsuspected planetary nebulae. Richmond hopes to use the new eyepiece with his Ultra Rich field 18" Newtonian with a stainless steel main mirror fabricated from a quality Chinese restaurant wok.