Jerome Klein - Island Park NY,
A method and apparatus that allows a ring to be inserted into the primary devices lens element or adapter without changing the offset (i.e., the distance between the camera and the lens along the optical path). This can be at the ocular or recording end of lenses. The ring can be hand turned and gently tightened with a key similar to a spanner wrench. The ring will maintain it's place and location when the amount of pressure applied to the accessory is less then that applied to the ring. When the insertion ring is in place, the screw mount diameter of the primary device is smaller without adding additional unnecessary offset when mounting the accessory. The present application covers the usage, design and manufacture of insertion rings, insertion ring keys and any modifications to the primary device.