Nikon AI Micro-NIKKOR 105mm f-4 - Manual (Page 9)

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
(°°) to 0.47m (1.55 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.
Note: The exact position of the film plane is indicat­
ed on all cameras for convenience when measuring.
On Nikon F/F2 cameras, the top edge of the serial
number is the exact position of the plane. On
other Nikon and Nikkormat cameras, the plane is
indicated by the symbol (-Q-)