<title>Measurement method of zooming by a cameraman</title>

摘要

We are developing an intelligent robot camera that is capable of automatically shooting images like those taken by broadcasting cameramen. In order to elucidate the zooming techniques of broadcasting cameramen, we developed the new measurement tool of zooming works which is able to be attached to or detached from broadcasting cameras easily. Then we measured the zooming works of broadcasting cameramen in shooting the images of still subject with this tool, and analyzed them. We confirmed that it is possible to reproduce faithfully the subtle zooming techniques of broadcasting cameramen. It was also established that when a cameraman shoots the same scene repeatedly in an improvised manner, the velocity of the operation rod follows almost the same velocity curve each time. This has led us to believe that the cameramen conduct zooming on the basis of a method acquired through individual experience. The frequency components of the operation rod's subtle velocity changes are from 5 to 10 Hz and the frequency levels of less than 5 Hz are especially large. The peak of variation of the subject's size is observed at the timing of 0.53 to 0.66 (the second half) during zoom-in operation and at the timing of 0.38 to 0.47 (the first half) during zoom-out operation, with both measured in terms of normalized zooming time.