Great post from No Film School
“If you’ve ever worked the first assistant camera position, or you pull your own focus, one of the most difficult parts of the job is making sure you’re pulling in sync with the movement of the actors. Often there is quite a bit of timing involved, especially with dolly moves. To do the job properly, you almost have to split your mind in two and watch the talent as you’re watching the marks on the follow focus, but a very simple trick can make that a little easier to accomplish.”
Looks a very cold spot to do a camera technique video.