Aperture Selector (fig 1-7) -
controls the action of the lens
diaphragm (opens or closes down,
with right to left movement).
Aperture Selector Pointer (fig
which is printed on the aperture
Figure 1-8. Aperture
Diaphragm Ring (fig 1-9) -
rotates (click stops) to preselect
the proper f/stop.
Selector will stop when being moved
from right to left, at the position
indicated by the Diaphragm Ring.