Basic Betacam Camerawork, 3rd Edition

Lens controls

The three main operational controls on the lens are focus, zoom and the lens aperture (f-number).

Focus: Sharp focus of the image is achieved by looking at the viewfinder image and either manually adjusting the focusing ring on the lens or by connecting a cable to the lens and controlling the focus by servo control mounted on a pan bar. Usually there is a switch on the zoom rocker module marked M (for manual control) and S (for servo control).

As we have discussed on page 39, the zoom must be pre-focused on its narrowest angle before recording a zoom into a subject, and the back focus of the lens must be correctly aligned (see page 43) for the sharpest focus to be maintained throughout the zoom.

If the required object in frame is ...