Its still manual focus, not autofocus, but it can be done remotely, which might allow for a remote focus puller software application, which would be nice if its fast enough.
I could imagine applications that let you set focus points corresponding to actors positions and saving them in the remote. Then just push the position number, letter, or title and the camera focuses to the memorized point. That would be a really neat app to have for a studio on a low budget, since it would basically eliminate the need for a full time focus puller. Just setup once, and it can be used over and over until a scene is finished.
Its been long known that manually focusing Canon EF lenses is difficult. The higher end ones with USM motors are even trickier, since they have a slip clutch and the point of rotation on the focus ring for a given distance can and will vary everytime the clutch slips. The clutch is required in order to have full time manual focus. It means that a focus puller's job is extremely difficult, a hard geared lens would pay fo itself in short order if you are filming with a studio full of expensive talent and operators.
A hard geared lens will always have repeatable focus, so you can set it by a mark on the lens and return to it.
