Bokeh is a form of art photography I discovered on Morguefile, in which much of the image is deliberately out of focus, for effect. It brought to mind the work of focus pullers, and the choreography of acting for screen when the focus puller has certain marks on the set that the actors must hit on time to stay in focus. What looks pell-mell in an action sequence may have to be very tightly controlled to work for camera. In the credits, the focus puller may also be called the first assistant cameraman. This may be one of the toughest jobs in all the credits, not least of all because when the focus isn’t perfect every penny of production value and every iota of fleeting inspiration that has gone into the shot has been wasted.
You rarely sense how closely the focus puller manipulates your gaze by choosing which parts of the image on your screen are in sharpest focus. There is occasionally a reveal, as when the doctor examining a Galapagos beetle in Master and Commander suddenly spots the Acheron in the distance. If manipulating the focus for that shot sounds tricky, now imagine doing it without looking through the lens! The camera operator must tell the focus puller whether or not the shot is in focus – only a knowledge of optics and cinematography tells the focus puller how to judge the distance. I found a detailed description of out-of-focus photography technique that hints at the complexity of the focus puller’s job.