Before the advent of autofocus, all cameras had manually adjusted focusing; thus, the term is a retronym.
Other methods include the rangefinder, which uses triangulation to determine the distance.
Twin lens reflex cameras use two lenses that are mechanically linked, one for focusing and the other to take the photograph.
Manual focus lenses can also be used on modern digital cameras with an adapter.
Zeiss, Leica and Cosina Voigtländer are among current manufacturers who continue to make manual lenses in lens mounts native to modern cameras.