Focal length, measured in millimeters (mm), describes the distance between the lens’s optical center and the camera sensor. This measurement directly impacts the field of view captured; shorter focal lengths (e.g., 16mm) yield a wider field of view, while longer focal lengths (e.g., 200mm) produce a narrower, more telephoto view. For example, a 50mm lens is often considered “normal” as it approximates human vision, offering a balanced perspective without significant distortion.
Understanding focal length is fundamental to video production. The chosen length dictates the apparent distance between the subject and the background, influencing perspective and depth of field. Its careful selection contributes significantly to the visual narrative, shaping the audience’s perception and emotional connection to the content. Historically, limitations in lens technology dictated the available range. Advances now provide filmmakers with a vast array of options, empowering greater creative control.