The fully automatic diaphragm of the Micro- Nikkor enables focusing with maximum image brightness throughout the entire focusing range of the lens. As the image is constantly viewed at the maximum aperture setting (i.e., f/4), the depth of field is minimized so that the image snaps in and out of focus rapidly and distinctly.
To focus, turn the focusing ring until the image on the focusing screen appears sharp and crisp. Via the special focusing helicoid, the Micro- Nikkor operates continuously from infinity
(oo)to 0.71m (2.34 ft) for a reproduction ratio of 1:2.
The distance scale on the focusing ring is marked in both meters (white) and feet (yel- low). These figures indicate the distance from the subject to the camera's film plane.