Nikon f2 - Manual (Page 56)

CHANGING THE LENS
To remove the lens from the camera, press the lens re­
lease button and, holding the button depressed, twist the
lens to the right as far as it will go. The lens will come
loose and can be lifted out.
To mount a lens, position it in the camera’s bayonet
mount so that the mounting index on the lens and the
camera are aligned; then, twist the lens counterclockwise
until it clicks and locks into place. While mounting the
lens, shade the camera from the sun with your body.
In order to measure exposure at full aperture with lenses
having different maximum apertures, the meter must be
indexed with the maximum aperture setting of the lens
in use. This must be done each time a lens is mounted, as
follows: After locking the lens in place, turn the aper­
ture ring all the way to the minimum aperture setting,
then all the way in the opposite direction. This step
automatically fits the coupling pin of the Photomic
finder into the coupling prong on the lens and adjusts
the meter to the maximum aperture of the lens.