The 5D Mark II Team has a good overview and demonstration of the prototype here. A 3rd party developer has created a USB control unit for Canon DSLRs which acts as a follow-focus, using the AF motors of the lens to gently rack focus via a large wheel on the device.
Browsing: follow focus
Above: who needs this rig when you have all the manual controls on your iPad? At some point in the midst of the early DSLR revolution I had an idea about a wireless follow focus which controlled the AF servo motors of a lens in a slow and steady way. Since then a couple of iPad / iPhone apps have been developed which do just this, but they require the…