Adapt a Video Focus Ring Gear for DSLR
Use soft rubber hose of the appropriate diameter. 5 or 6 pieces will keep the ring centered perfectly. Pictured here is a DVX100 focus ring gear that will work on many Canon and Nikon zoom lenses.
Video Focus Ring Gear for DSLR
Video Focus Ring Gear for DSLR
Video Focus Ring Gear for DSLR