ABSTRACT
A long focus lens, almost never called a ‘narrow-angle’ lens, in contrast to the use of the term ‘wide-angle’, is one whose focal length exceeds the length of the diagonal of the film format in use. Medium long focus (MLF) lenses, depending on construction, can be of large aperture, from f/1.2 to f/2.8 depending on focal length. A MLF lens for cine work is often called a pack shot lens, since the even more distant viewpoint for a regular-sided subject allows a higher viewpoint with acceptable perspective and subject shape, as there are no rising or falling lens movements normally available on a cine camera. The symmetrical lens could be produced in MLF versions, with exceptional covering power for a given format and possibly with the feature of being convertible to a longer extreme long focus by using the front or rear component alone.
