Nikon EL2 - Manual (Page 50)

STOP-DOWN EXPOSURE MEASUREMENT
With some Nikkor lenses, full-aperture exposure mea­
surement is not possible, either because the lens has no
automatic diaphragm, or because the lens does not cou­
ple with the built-in meter; with certain accessories,
too, lens/meter coupling is not possible, thus, prevent­
ing full-aperture measurement. However, the camera’s
meter can still be used for exposure measurement via
the stop-down method. Before mounting the lens (or
accessory) on the camera body, lock the meter cou­
pling lever in the up position, as described in “Cou­
pling Lever Lock/Release Operation” on page 43; the
lever must remain up as long as stop-down measure­
ment is being performed. After setting the lever, mount
the lens or lens/accessory combination on the camera,
switch on the meter by moving the film-advance lever
to the standoff position (or moving the shutter-release
button lock to the left), and then set the controls for
correct exposure as follows:
For fixed-aperture lenses, such as Reflex-Nikkor lenses,
choose the desired shutter speed operation mode (ei­
ther automatic or manual selection) first. When auto­
matic shutter speed selection is used, no additional set­
tings are required; when manual speed selection is used,
adjust the shutter-speed dial until the meter needles in
the finder overlap. The exposure can additionally be
controlled via built-in or accessory ND filters.