Thanks for the reply's.
The lens is an 8mm fisheye which has a large DOF. When set to the hyperfocal(1.5m) distance for what I shoot, everything from 1m to infinity is in focus. The aperture performs best at f8.
So to alleviate having to check it everytime I shoot, I locked it to the preferred settings with the printed ring. I only shoot full spherical panoramas with this lens. Many people who shoot panoramas use duct tape to lock the focus and aperture. I just couldn't bring myself to use the duct tape.(and I love duct tape) Especially now that I can just print things of this nature.(yay Shapeways)
ps. examples of my work can be found at Buffalo VRBuffalo, 360Â° @ a time