Lenses are characterized by their focal length (between the optical center and the film), aperture (ratio between the diameter of the lens and the focal length) and angle of view (width of the captured image).
Lens that produces an image close to that seen by the human eye.
lens aperture scale
Graduated scale that controls the diaphragm’s opening; it is measured in f-stops and a high f-stop indicates a small opening.
Scale that shows the zone of sharpest focus around the subject; this is a function of the diaphragm’s opening and the distance between the lens and the subject.
Scale that shows the distance between the lens and the subject on which it is focused.
Device for attaching the lens to the camera body by fitting lugs located on the lens into grooves on the camera and turning.
focus setting ring
Setting ring that sharpens the image of a subject.
Transparent optical disks through which ambient light enters; the disks correct each other to improve the quality of the image.